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22 - 安全护栏

版本说明

本文档基于 LangChain4j 1.10.0 版本编写。

学习目标

通过本章节学习，你将能够：

理解 LangChain4j 中安全护栏的概念和重要性
掌握 @ModerateModel 注解的使用
学会实现内容审核和安全检查
理解输出验证和过滤
掌握速率限制和配额控制
实现一个完整的安全护栏解决方案

前置知识

完成《01 - LangChain4j 简介》章节
完成《02 - 你的第一个 Chat 应用》章节

核心概念

什么是安全护栏？

安全护栏（Guardrails）是指在 LLM 应用中实施的安全措施，用于：

控制模型的输入和输出
防止有害或不当内容
确保应用符合政策和法规
保护用户免受不良信息影响

类比理解：

无护栏的 LLM = 高速公路上没有护栏，可能偏离路线
有护栏的 LLM = 铁路两侧有护栏，确保安全行驶

为什么需要安全护栏？

安全挑战：

有害内容
- 暴力、仇恨言论
- 非法内容
- 不当信息
隐私问题
- 泄露敏感信息
- 个人身份信息（PII）
- 商业机密
合规要求
- GDPR 等数据保护法规
- 行业标准（医疗、金融）
- 内容分级要求
用户体验
- 不当内容影响品牌形象
- 破坏用户信任
- 导致负面的社会影响

基础安全护栏

内容审核

import dev.langchain4j.service.AiServices;
import dev.langchain4j.service.SystemMessage;
import dev.langchain4j.model.chat.ChatModel;
import dev.langchain4j.model.openai.OpenAiChatModel;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 内容审核示例
 */
public class ContentModerationExample {

    private static final Logger logger = LoggerFactory.getLogger(ContentModerationExample.class);

    /**
     * 审核结果
     */
    public static class ModerationResult {
        private final boolean isAllowed;
        private final String reason;
        private final ModerationCategory category;
        private final double confidence;

        public ModerationResult(boolean isAllowed, String reason, 
                             ModerationCategory category, double confidence) {
            this.isAllowed = isAllowed;
            this.reason = reason;
            this.category = category;
            this.confidence = confidence;
        }

        public boolean isAllowed() { return isAllowed; }
        public String getReason() { return reason; }
        public ModerationCategory getCategory() { return category; }
        public double getConfidence() { return confidence; }
    }

    /**
     * 审核类别
     */
    public enum ModerationCategory {
        SAFE("安全"),
        VIOLENCE("暴力"),
        HATE("仇恨"),
        SEXUAL("色情"),
        ILLEGAL("非法"),
        INAPPROPRIATE("不当"),
        PRIVACY("隐私"),
        UNKNOWN("未知");

        private final String description;

        ModerationCategory(String description) {
            this.description = description;
        }

        public String getDescription() { return description; }
    }

    /**
     * 审核服务
     */
    @AiService
    public interface ContentModerationService {
        /**
         * 审核文本内容
         */
        ModerationResult moderateText(String text);
    }

    /**
     * 创建审核服务
     */
    public static ContentModerationService createModerationService(String apiKey) {
        return AiServices.builder(ContentModerationService.class)
                .chatModel(OpenAiChatModel.builder()
                        .apiKey(apiKey)
                        .modelName("gpt-4o-mini")
                        .build())
                .systemMessageProvider(chatMemoryId -> 
                    "你是一个内容审核专家。" +
                    "你的任务是分析给定的文本内容，判断其是否安全。" +
                    "请检查以下方面：" +
                    "1. 是否包含暴力、仇恨、色情等不当内容" +
                    "2. 是否包含非法内容（如毒品、武器等）" +
                    "3. 是否包含不当言论或冒犯性语言" +
                    "4. 是否包含个人隐私信息（如电话号码、地址等）" +
                    "如果内容安全，返回 isAllowed=true，category=SAFE" +
                    "如果内容不安全，返回 isAllowed=false，" +
                    "并指定具体的违规类别（VIOLENCE、HATE、SEXUAL、ILLEGAL、INAPPROPRIATE、PRIVACY之一）" +
                    "对于每个判断，提供 confidence（0.0 到 1.0）表示确信程度" +
                    "同时提供 reason 简要说明违规原因。"
                )
                .build();
    }

    /**
     * 带安全护栏的聊天
     */
    public static String chatWithGuardrails(
            ContentModerationService moderationService,
            ChatModel model,
            String message
    ) {
        // 审核输入
        ModerationResult moderationResult = moderationService.moderateText(message);

        if (!moderationResult.isAllowed()) {
            logger.warn("消息未通过审核: {}", moderationResult.getReason());
            return "抱歉，您的消息违反了我们的内容政策。";
        }

        // 消息安全，正常处理
        logger.info("消息通过审核: {}", message);
        return model.chat(message);
    }

    public static void main(String[] args) {
        String apiKey = System.getenv("OPENAI_API_KEY");

        // 创建审核服务
        ContentModerationService moderationService = createModerationService(apiKey);

        // 创建聊天模型
        ChatModel model = OpenAiChatModel.builder()
                .apiKey(apiKey)
                .modelName("gpt-4o-mini")
                .build();

        // 测试安全消息
        String safeMessage = "你好，请问今天天气如何？";
        String response1 = chatWithGuardrails(moderationService, model, safeMessage);
        System.out.println("用户: " + safeMessage);
        System.out.println("AI: " + response1);
        System.out.println();

        // 测试不安全消息
        String unsafeMessage = "我讨厌所有人，我要报复他们！";
        String response2 = chatWithGuardrails(moderationService, model, unsafeMessage);
        System.out.println("用户: " + unsafeMessage);
        System.out.println("AI: " + response2);
    }
}

输入验证

输入过滤

import dev.langchain4j.service.AiServices;
import dev.langchain4j.service.SystemMessage;
import dev.langchain4j.model.chat.ChatModel;
import dev.langchain4j.model.openai.OpenAiChatModel;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.List;
import java.util.regex.Pattern;

/**
 * 输入验证示例
 */
public class InputValidationExample {

    private static final Logger logger = LoggerFactory.getLogger(InputValidationExample.class);

    /**
     * 验证规则
     */
    public static class ValidationRule {
        private final String name;
        private final Pattern pattern;
        private final String description;

        public ValidationRule(String name, String pattern, String description) {
            this.name = name;
            this.pattern = Pattern.compile(pattern, Pattern.CASE_INSENSITIVE);
            this.description = description;
        }

        public String getName() { return name; }
        public Pattern getPattern() { return pattern; }
        public String getDescription() { return description; }
    }

    /**
     * 验证结果
     */
    public static class ValidationResult {
        private final boolean isValid;
        private final String message;
        private final List<String> violatedRules;

        public ValidationResult(boolean isValid, String message, List<String> violatedRules) {
            this.isValid = isValid;
            this.message = message;
            this.violatedRules = violatedRules;
        }

        public boolean isValid() { return isValid; }
        public String getMessage() { return message; }
        public List<String> getViolatedRules() { return violatedRules; }
    }

    /**
     * 验证配置
     */
    public static class ValidationConfig {
        private final int maxLength;
        private final int minLength;
        private final List<ValidationRule> rules;
        private final boolean checkSensitiveData;

        public ValidationConfig(int maxLength, int minLength, 
                           List<ValidationRule> rules, boolean checkSensitiveData) {
            this.maxLength = maxLength;
            this.minLength = minLength;
            this.rules = rules;
            this.checkSensitiveData = checkSensitiveData;
        }

        public int getMaxLength() { return maxLength; }
        public int getMinLength() { return minLength; }
        public List<ValidationRule> getRules() { return rules; }
        public boolean isCheckSensitiveData() { return checkSensitiveData; }
    }

    /**
     * 验证服务
     */
    @AiService
    public interface InputValidationService {
        /**
         * 验证输入
         */
        ValidationResult validateInput(String input);
    }

    /**
     * 创建默认验证配置
     */
    public static ValidationConfig createDefaultValidationConfig() {
        List<ValidationRule> rules = new ArrayList<>();

        // 长度规则
        rules.add(new ValidationRule(
            "max_length",
            "^.{0,1000}$",
            "输入不能超过 1000 个字符"
        ));

        // 内容规则
        rules.add(new ValidationRule(
            "no_email",
            "[\\w\\.\\-]+@[\\w\\.\\-]+\\.[a-zA-Z]{2,}",
            "请勿在输入中提供邮箱地址"
        ));

        rules.add(new ValidationRule(
            "no_phone",
            "\\d{11}",
            "请勿在输入中提供电话号码"
        ));

        rules.add(new ValidationRule(
            "no_url",
            "https?://[\\w\\-]+(\\.[\\w\\-]+)+[/\\w\\-?=%&]*",
            "请勿在输入中提供 URL"
        ));

        // 不当内容规则
        rules.add(new ValidationRule(
            "no_profanity",
            "(暴力|仇恨|色情|毒品|赌博)",
            "输入中包含不当内容"
        ));

        return new ValidationConfig(
                1000,          // 最大长度
                1,             // 最小长度
                rules,
                true           // 检查敏感数据
        );
    }

    /**
     * 验证输入
     */
    public static ValidationResult validateInput(String input, ValidationConfig config) {
        List<String> violatedRules = new ArrayList<>();

        // 检查长度
        if (input.length() > config.getMaxLength()) {
            violatedRules.add("max_length");
        } else if (input.length() < config.getMinLength()) {
            violatedRules.add("min_length");
        }

        // 检查各项规则
        for (ValidationRule rule : config.getRules()) {
            if (rule.getPattern().matcher(input).find()) {
                violatedRules.add(rule.getName());
            }
        }

        // 检查敏感数据
        if (config.isCheckSensitiveData()) {
            if (containsSensitiveData(input)) {
                violatedRules.add("sensitive_data");
            }
        }

        // 生成结果
        if (violatedRules.isEmpty()) {
            return new ValidationResult(true, "输入有效", List.of());
        } else {
            String message = String.format("输入违反了以下规则: %s", 
                        String.join(", ", violatedRules));
            return new ValidationResult(false, message, violatedRules);
        }
    }

    /**
     * 检查敏感数据
     */
    private static boolean containsSensitiveData(String input) {
        // 简化实现：实际应该使用更复杂的规则
        String[] sensitiveKeywords = {
            "身份证", "护照", "银行卡", "密码", "信用卡",
            "账号", "密码", "支付", "转账", "地址", "电话"
        };

        String lowerInput = input.toLowerCase();
        for (String keyword : sensitiveKeywords) {
            if (lowerInput.contains(keyword.toLowerCase())) {
                return true;
            }
        }

        return false;
    }

    /**
     * 创建验证服务
     */
    public static InputValidationService createValidationService(String apiKey, ValidationConfig config) {
        return AiServices.builder(InputValidationService.class)
                .chatModel(OpenAiChatModel.builder()
                        .apiKey(apiKey)
                        .modelName("gpt-4o-mini")
                        .build())
                .systemMessageProvider(chatMemoryId -> 
                    "你是一个输入验证专家。" +
                    "你的任务是分析用户的输入，判断其是否符合指定的验证规则。" +
                    "请检查：" +
                    "1. 输入长度是否在允许范围内" +
                    "2. 输入是否包含邮箱地址、电话号码、URL 等敏感信息" +
                    "3. 输入是否包含暴力、仇恨、色情等不当内容" +
                    "4. 输入是否违反任何其他指定的规则" +
                    "如果输入有效，返回 isValid=true" +
                    "如果输入无效，返回 isValid=false，" +
                    "并列出所有被违反的规则名称。" +
                    "规则包括: " + String.join(", ", 
                        config.getRules().stream()
                                .map(ValidationRule::getName)
                                .toArray(String[]::new)) +
                    "。" +
                    "提供 message 简要说明验证结果。"
                )
                .build();
    }

    public static void main(String[] args) {
        String apiKey = System.getenv("OPENAI_API_KEY");

        // 创建验证配置
        ValidationConfig config = createDefaultValidationConfig();

        // 创建验证服务
        InputValidationService validationService = createValidationService(apiKey, config);

        // 测试有效输入
        String validInput = "你好，我想了解一下天气预报";
        ValidationResult result1 = validationService.validateInput(validInput);
        System.out.println("输入: " + validInput);
        System.out.println("验证结果: " + result1.isValid());
        System.out.println("消息: " + result1.getMessage());
        System.out.println();

        // 测试无效输入
        String invalidInput = "我的邮箱是 [email protected]，电话 13800138000，我想报复所有人！";
        ValidationResult result2 = validationService.validateInput(invalidInput);
        System.out.println("输入: " + invalidInput);
        System.out.println("验证结果: " + result2.isValid());
        System.out.println("违规规则: " + String.join(", ", result2.getViolatedRules()));
        System.out.println("消息: " + result2.getMessage());
    }
}

输出过滤

输出审核

import dev.langchain4j.model.chat.ChatModel;
import dev.langchain4j.data.message.AiMessage;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 输出过滤示例
 */
public class OutputFilteringExample {

    private static final Logger logger = LoggerFactory.getLogger(OutputFilteringExample.class);

    /**
     * 过滤规则
     */
    public static class FilterRule {
        private final String name;
        private final Pattern pattern;
        private final String replacement;
        private final String description;

        public FilterRule(String name, String pattern, String replacement, String description) {
            this.name = name;
            this.pattern = Pattern.compile(pattern, Pattern.CASE_INSENSITIVE);
            this.replacement = replacement;
            this.description = description;
        }

        public String getName() { return name; }
        public Pattern getPattern() { return pattern; }
        public String getReplacement() { return replacement; }
        public String getDescription() { return description; }
    }

    /**
     * 过滤结果
     */
    public static class FilterResult {
        private final String originalOutput;
        private final String filteredOutput;
        private final List<FilterRule> appliedRules;

        public FilterResult(String originalOutput, String filteredOutput, List<FilterRule> appliedRules) {
            this.originalOutput = originalOutput;
            this.filteredOutput = filteredOutput;
            this.appliedRules = appliedRules;
        }

        public String getOriginalOutput() { return originalOutput; }
        public String getFilteredOutput() { return filteredOutput; }
        public List<FilterRule> getAppliedRules() { return appliedRules; }
    }

    /**
     * 过滤配置
     */
    public static class FilterConfig {
        private final List<FilterRule> filterRules;
        private final boolean applyAllRules;
        private final boolean logFilteredContent;

        public FilterConfig(List<FilterRule> filterRules, boolean applyAllRules, boolean logFilteredContent) {
            this.filterRules = filterRules;
            this.applyAllRules = applyAllRules;
            this.logFilteredContent = logFilteredContent;
        }

        public List<FilterRule> getFilterRules() { return filterRules; }
        public boolean isApplyAllRules() { return applyAllRules; }
        public boolean isLogFilteredContent() { return logFilteredContent; }
    }

    /**
     * 创建默认过滤配置
     */
    public static FilterConfig createDefaultFilterConfig() {
        List<FilterRule> rules = new ArrayList<>();

        // 个人信息过滤
        rules.add(new FilterRule(
            "remove_email",
            "\\b[\\w\\.\\-]+@[\\w\\.\\-]+\\.[a-zA-Z]{2,}\\b",
            "[已过滤邮箱地址]",
            "移除个人邮箱地址"
        ));

        rules.add(new FilterRule(
            "remove_phone",
            "\\d{11}",
            "[已过滤电话号码]",
            "移除个人电话号码"
        ));

        // 不当内容过滤
        rules.add(new FilterRule(
            "remove_profanity",
            "暴力|仇恨|色情|毒品|赌博",
            "[已过滤不当内容]",
            "移除不当言论"
        ));

        // API 密钥过滤
        rules.add(new FilterRule(
            "remove_api_key",
            "sk-[a-zA-Z0-9]{48}",
            "[已过滤 API Key]",
            "移除敏感凭证"
        ));

        return new FilterConfig(
                rules,
                true,   // 应用所有过滤规则
                true    // 记录过滤内容
        );
    }

    /**
     * 过滤输出
     */
    public static FilterResult filterOutput(String output, FilterConfig config) {
        String filteredOutput = output;
        List<FilterRule> appliedRules = new ArrayList<>();

        // 应用每个过滤规则
        for (FilterRule rule : config.getFilterRules()) {
            String previousOutput = filteredOutput;
            filteredOutput = rule.getPattern().matcher(filteredOutput).replaceAll(rule.getReplacement());

            if (!previousOutput.equals(filteredOutput)) {
                appliedRules.add(rule);
                if (config.isLogFilteredContent()) {
                    logger.info("应用过滤规则 '{}': {}", rule.getName(), rule.getDescription());
                }
            }
        }

        return new FilterResult(output, filteredOutput, appliedRules);
    }

    /**
     * 带过滤的生成
     */
    public static String generateWithFilter(
            ChatModel model,
            FilterConfig filterConfig,
            String prompt
    ) {
        // 生成原始响应
        String rawResponse = model.chat(prompt);

        // 过滤响应
        FilterResult filterResult = filterOutput(rawResponse, filterConfig);

        if (!filterResult.getAppliedRules().isEmpty()) {
            logger.info("响应已应用 {} 个过滤规则", filterResult.getAppliedRules().size());
        }

        return filterResult.getFilteredOutput();
    }

    public static void main(String[] args) {
        String apiKey = System.getenv("OPENAI_API_KEY");

        // 创建模型
        ChatModel model = OpenAiChatModel.builder()
                .apiKey(apiKey)
                .modelName("gpt-4o-mini")
                .build();

        // 创建过滤配置
        FilterConfig filterConfig = createDefaultFilterConfig();

        // 测试过滤
        String prompt = "我的邮箱是 [email protected]，电话 13800138000，API Key 是 sk-1234567890，" +
                     "你可以看到我的银行卡号吗？";

        System.out.println("╔═════════════════════════════════════════════════════╗");
        System.out.println("║              输出过滤示例                              ║");
        System.out.println("╠═════════════════════════════════════════════════════╣");
        System.out.println("║ 提示词:                                                 ║");
        System.out.println("║ " + prompt);
        System.out.println("╠═════════════════════════════════════════════════════╣");

        String filteredResponse = generateWithFilter(model, filterConfig, prompt);

        System.out.println("║ 原始响应:                                               ║");
        System.out.println("║ " + model.chat(prompt).substring(0, Math.min(100, model.chat(prompt).length())));
        System.out.println("╠─────────────────────────────────────────────────────╣");
        System.out.println("║ 过滤后响应:                                               ║");
        System.out.println("║ " + filteredResponse.substring(0, Math.min(100, filteredResponse.length())));
        System.out.println("╚═══════════════════════════════════════════════════════════╝");
    }
}

速率限制

请求限流

import dev.langchain4j.service.AiServices;
import dev.langchain4j.service.SystemMessage;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicLong;
import java.time.LocalDateTime;
import java.time.format.DateTimeFormatter;

/**
 * 速率限制示例
 */
public class RateLimitingExample {

    private static final Logger logger = LoggerFactory.getLogger(RateLimitingExample.class);

    /**
     * 速率限制配置
     */
    public static class RateLimitConfig {
        private final int maxRequestsPerMinute;
        private final int maxRequestsPerHour;
        private final int maxRequestsPerDay;
        private final int burstLimit;

        public RateLimitConfig(int maxRequestsPerMinute, int maxRequestsPerHour,
                            int maxRequestsPerDay, int burstLimit) {
            this.maxRequestsPerMinute = maxRequestsPerMinute;
            this.maxRequestsPerHour = maxRequestsPerHour;
            this.maxRequestsPerDay = maxRequestsPerDay;
            this.burstLimit = burstLimit;
        }

        public int getMaxRequestsPerMinute() { return maxRequestsPerMinute; }
        public int getMaxRequestsPerHour() { return maxRequestsPerHour; }
        public int getMaxRequestsPerDay() { return maxRequestsPerDay; }
        public int getBurstLimit() { return burstLimit; }
    }

    /**
     * 速率限制状态
     */
    public static class RateLimitState {
        private final String userId;
        private final AtomicLong requestsInLastMinute;
        private final AtomicLong requestsInLastHour;
        private final AtomicLong requestsInLastDay;
        private volatile long lastResetTime;
        private final String lastRateLimitReset;

        public RateLimitState(String userId) {
            this.userId = userId;
            this.requestsInLastMinute = new AtomicLong(0);
            this.requestsInLastHour = new AtomicLong(0);
            this.requestsInLastDay = new AtomicLong(0);
            this.lastResetTime = System.currentTimeMillis();
            this.lastRateLimitReset = LocalDateTime.now().toString();
        }

        public String getUserId() { return userId; }
        public long getRequestsInLastMinute() { return requestsInLastMinute.get(); }
        public long getRequestsInLastHour() { return requestsInLastHour.get(); }
        public long getRequestsInLastDay() { return requestsInLastDay.get(); }
        public String getLastRateLimitReset() { return lastRateLimitReset; }
    }

    /**
     * 速率限制管理器
     */
    public static class RateLimiter {
        private final Map<String, RateLimitState> userStates;
        private final RateLimitConfig config;

        public RateLimiter(RateLimitConfig config) {
            this.userStates = new ConcurrentHashMap<>();
            this.config = config;
        }

        /**
         * 检查速率限制
         */
        public RateLimitResult checkRateLimit(String userId) {
            RateLimitState state = userStates.computeIfAbsent(userId, RateLimitState::new);

            // 检查突发限制
            if (state.getRequestsInLastMinute().get() >= config.getBurstLimit()) {
                logger.warn("用户 {} 触发突发限制", userId);
                return new RateLimitResult(false, "请求过于频繁", 
                                      state.getLastRateLimitReset());
            }

            // 检查每分钟限制
            if (state.getRequestsInLastMinute().get() >= config.getMaxRequestsPerMinute()) {
                logger.warn("用户 {} 超过每分钟请求限制", userId);
                return new RateLimitResult(false, "每分钟请求限制", 
                                      state.getLastRateLimitReset());
            }

            // 检查每小时限制
            if (state.getRequestsInLastHour().get() >= config.getMaxRequestsPerHour()) {
                logger.warn("用户 {} 超过每小时请求限制", userId);
                return new RateLimitResult(false, "每小时请求限制", 
                                      state.getLastRateLimitReset());
            }

            // 检查每天限制
            if (state.getRequestsInLastDay().get() >= config.getMaxRequestsPerDay()) {
                logger.warn("用户 {} 超过每天请求限制", userId);
                return new RateLimitResult(false, "每天请求限制", 
                                      state.getLastRateLimitReset());
            }

            // 通过检查，增加计数
            state.requestsInLastMinute.incrementAndGet();
            state.requestsInLastHour.incrementAndGet();
            state.requestsInLastDay.incrementAndGet();

            return new RateLimitResult(true, "允许", state.getLastRateLimitReset());
        }

        /**
         * 重置用户状态
         */
        public void resetUserState(String userId) {
            RateLimitState state = userStates.get(userId);
            if (state != null) {
                state.requestsInLastMinute.set(0);
                state.requestsInLastHour.set(0);
                state.requestsInLastDay.set(0);
                state.lastRateLimitReset = LocalDateTime.now().toString();
                logger.info("重置用户 {} 的速率限制状态", userId);
            }
        }

        /**
         * 获取用户状态
         */
        public RateLimitState getUserState(String userId) {
            return userStates.get(userId);
        }

        /**
         * 获取所有用户状态
         */
        public Map<String, RateLimitState> getAllUserStates() {
            return new ConcurrentHashMap<>(userStates);
        }
    }

    /**
     * 速率限制结果
     */
    public static class RateLimitResult {
        private final boolean isAllowed;
        private final String message;
        private final String resetTime;

        public RateLimitResult(boolean isAllowed, String message, String resetTime) {
            this.isAllowed = isAllowed;
            this.message = message;
            this.resetTime = resetTime;
        }

        public boolean isAllowed() { return isAllowed; }
        public String getMessage() { return message; }
        public String getResetTime() { return resetTime; }
    }

    /**
     * 创建默认速率限制配置
     */
    public static RateLimitConfig createDefaultRateLimitConfig() {
        return new RateLimitConfig(
                60,      // 每分钟最多 60 次请求
                1000,    // 每小时最多 1000 次请求
                10000,   // 每天最多 10000 次请求
                10       // 突发限制：每分钟最多 10 次请求
        );
    }

    public static void main(String[] args) {
        // 创建速率限制器
        RateLimiter limiter = new RateLimiter(createDefaultRateLimitConfig());

        String testUser = "user123";

        System.out.println("╔═════════════════════════════════════════════════════════════╗");
        System.out.println("║              速率限制示例                              ║");
        System.out.println("╠═══════════════════════════════════════════════════════════╣");
        System.out.println("║ 用户 ID: " + testUser);
        System.out.println("╠═══════════════════════════════════════════════════════════╣");

        // 模拟请求
        for (int i = 1; i <= 80; i++) {
            RateLimitResult result = limiter.checkRateLimit(testUser);

            String status = result.isAllowed() ? "✅ 允许" : "❌ 拒绝";
            String statusColor = result.isAllowed() ? "绿色" : "红色";

            System.out.printf("║ 请求 [%3d] %s %s - %s                            ║\n",
                        i,
                        status,
                        statusColor,
                        result.getMessage());

            if (!result.isAllowed() && i % 20 == 0) {
                System.out.println("╠─────────────────────────────────────────────────────────────╣");
                System.out.println("║ 重置用户状态                                         ║\n");
                limiter.resetUserState(testUser);
            }
        }

        System.out.println("╚═════════════════════════════════════════════════════════════════════╝");
    }
}

综合安全系统

完整的安全护栏

import dev.langchain4j.service.AiServices;
import dev.langchain4j.model.chat.ChatModel;
import dev.langchain4j.model.openai.OpenAiChatModel;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 综合安全系统
 */
public class SecurityGuardrails {

    private static final Logger logger = LoggerFactory.getLogger(SecurityGuardrails.class);

    /**
     * 安全事件
     */
    public static class SecurityEvent {
        private final String eventId;
        private final String eventType;
        private final String userId;
        private final String message;
        private final Map<String, Object> details;
        private final long timestamp;

        public SecurityEvent(String eventType, String userId, String message, 
                            Map<String, Object> details) {
            this.eventId = generateEventId();
            this.eventType = eventType;
            this.userId = userId;
            this.message = message;
            this.details = details;
            this.timestamp = System.currentTimeMillis();
        }

        // Getters
        public String getEventId() { return eventId; }
        public String getEventType() { return eventType; }
        public String getUserId() { return userId; }
        public String getMessage() { return message; }
        public Map<String, Object> getDetails() { return details; }
        public long getTimestamp() { return timestamp; }

        private static String generateEventId() {
            return "SEC-" + System.currentTimeMillis() + "-" + 
                   Integer.toHexString((int) (Math.random() * 10000));
        }
    }

    /**
     * 安全策略
     */
    public static class SecurityPolicy {
        private final String policyId;
        private final String policyName;
        private final String description;
        private final boolean isEnabled;
        private final String action;

        public SecurityPolicy(String policyId, String policyName, String description, 
                             boolean isEnabled, String action) {
            this.policyId = policyId;
            this.policyName = policyName;
            this.description = description;
            this.isEnabled = isEnabled;
            this.action = action;
        }

        // Getters
        public String getPolicyId() { return policyId; }
        public String getPolicyName() { return policyName; }
        public String getDescription() { return description; }
        public boolean isEnabled() { return isEnabled; }
        public String getAction() { return action; }
    }

    /**
     * 安全策略管理器
     */
    public static class SecurityPolicyManager {
        private final Map<String, SecurityPolicy> policies;
        private final List<SecurityEvent> securityEvents;

        public SecurityPolicyManager() {
            this.policies = new ConcurrentHashMap<>();
            this.securityEvents = new ArrayList<>();
        }

        /**
         * 添加安全策略
         */
        public void addPolicy(SecurityPolicy policy) {
            policies.put(policy.getPolicyId(), policy);
            logger.info("添加安全策略: {} - {}", policy.getPolicyName(), policy.getDescription());
        }

        /**
         * 检查策略违规
         */
        public List<SecurityPolicy> checkPolicyViolations(String input, String userId) {
            List<SecurityPolicy> violations = new ArrayList<>();

            for (SecurityPolicy policy : policies.values()) {
                if (!policy.isEnabled()) {
                    continue;
                }

                // 检查政策违规
                if (isPolicyViolation(input, policy)) {
                    violations.add(policy);

                    // 记录安全事件
                    recordSecurityEvent("POLICY_VIOLATION", userId, policy.getPolicyName(), policy.getPolicyId());
                }
            }

            return violations;
        }

        /**
         * 检查是否违反政策
         */
        private boolean isPolicyViolation(String input, SecurityPolicy policy) {
            // 简化：实际应该根据政策类型进行不同的检查
            return switch (policy.getPolicyId()) {
                case "content_moderation" -> false;  // 由专门的审核服务处理
                case "rate_limiting" -> false;  // 由速率限制器处理
                case "input_validation" -> false;  // 由输入验证处理
                default -> false;
            };
        }

        /**
         * 记录安全事件
         */
        public void recordSecurityEvent(String eventType, String userId, String message, String policyId) {
            Map<String, Object> details = new ConcurrentHashMap<>();
            details.put("policyId", policyId);
            details.put("timestamp", System.currentTimeMillis());

            SecurityEvent event = new SecurityEvent(eventType, userId, message, details);
            securityEvents.add(event);

            logger.warn("安全事件 - 类型: {}, 用户: {}, 策略: {}", 
                        eventType, userId, policyId);
        }

        /**
         * 获取安全事件
         */
        public List<SecurityEvent> getSecurityEvents() {
            return new ArrayList<>(securityEvents);
        }

        /**
         * 生成安全报告
         */
        public String generateSecurityReport() {
            StringBuilder report = new StringBuilder();
            report.append("╔═════════════════════════════════════════════════════════════════════╗\n");
            report.append("║              安全报告                                      ║\n");
            report.append("╠═════════════════════════════════════════════════════════════════════╣\n");
            report.append("║ 安全政策总数: ").append(policies.size()).append("\n");
            report.append("╠═════════════════════════════════════════════════════════════════════╣\n");
            report.append("║ 安全事件总数: ").append(securityEvents.size()).append("\n");
            report.append("╠═════════════════════════════════════════════════════════════════════╣\n");

            // 按事件类型分组
            Map<String, Integer> eventCounts = new HashMap<>();
            for (SecurityEvent event : securityEvents) {
                eventCounts.merge(event.getEventType(), 1, Integer::sum);
            }

            eventCounts.forEach((eventType, count) -> {
                report.append("║   ").append(eventType).append(": ").append(count).append(" 次\n");
            });

            report.append("╠═════════════════════════════════════════════════════════════════════╣\n");
            report.append("║ 时间: ").append(
                java.time.LocalDateTime.now().format(java.time.format.DateTimeFormatter.ISO_LOCAL_DATE_TIME))
            ).append("\n");
            report.append("╚═════════════════════════════════════════════════════════════════════════════╝\n");

            return report.toString();
        }
    }

    /**
     * 安全护栏服务
     */
    @AiService
    public interface SecurityGuardrailsService {
        /**
         * 安全检查
         */
        SecurityCheckResult performSecurityCheck(String input, String userId);
    }

    /**
     * 安全检查结果
     */
    public static class SecurityCheckResult {
        private final boolean isSafe;
        private final List<SecurityPolicy> violations;
        private final String message;
        private final SecurityAction action;

        public SecurityCheckResult(boolean isSafe, List<SecurityPolicy> violations, 
                                   String message, SecurityAction action) {
            this.isSafe = isSafe;
            this.violations = violations;
            this.message = message;
            this.action = action;
        }

        public boolean isSafe() { return isSafe; }
        public List<SecurityPolicy> getViolations() { return violations; }
        public String getMessage() { return message; }
        public SecurityAction getAction() { return action; }
    }

    /**
     * 安全行动
     */
    public enum SecurityAction {
        ALLOW("允许"),
        BLOCK("阻止"),
        MODERATE("审核"),
        RATE_LIMIT("限流"),
        FILTER("过滤"),
        LOG_ONLY("仅记录")
    }

    public static void main(String[] args) {
        String apiKey = System.getenv("OPENAI_API_KEY");

        // 创建安全政策管理器
        SecurityPolicyManager policyManager = new SecurityPolicyManager();

        // 添加安全政策
        policyManager.addPolicy(new SecurityPolicy(
            "content_moderation",
            "内容审核",
            "禁止有害、暴力、仇恨、色情等不当内容",
            true,
            "BLOCK"
        ));

        policyManager.addPolicy(new SecurityPolicy(
            "input_validation",
            "输入验证",
            "验证输入长度、格式和内容",
            true,
            "REJECT"
        ));

        policyManager.addPolicy(new SecurityPolicy(
            "rate_limiting",
            "速率限制",
            "限制用户请求频率",
            true,
            "RATE_LIMIT"
        ));

        policyManager.addPolicy(new SecurityPolicy(
            "output_filtering",
            "输出过滤",
            "过滤输出中的敏感信息",
            true,
            "FILTER"
        ));

        // 生成安全报告
        System.out.println(policyManager.generateSecurityReport());
    }
}

测试代码示例

import dev.langchain4j.service.AiServices;
import dev.langchain4j.model.chat.ChatModel;
import dev.langchain4j.model.openai.OpenAiChatModel;

import org.junit.jupiter.api.*;
import static org.junit.jupiter.api.Assertions.*;

/**
 * 安全护栏测试
 */
class GuardrailsTest {

    @Test
    void should_reject_harmful_content() {
        // 创建审核服务
        String apiKey = System.getenv("OPENAI_API_KEY");
        ContentModerationService service = ContentModerationExample.createModerationService(apiKey);

        // 测试有害内容
        ModerationResult result = service.moderateText("我要杀了所有的人");

        // 验证
        assertFalse(result.isAllowed());
        assertTrue(result.getCategory() == ContentModerationExample.ModerationCategory.VIOLENCE || 
                   result.getCategory() == ContentModerationExample.ModerationCategory.HATE);
    }

    @Test
    void should_allow_safe_content() {
        String apiKey = System.getenv("OPENAI_API_KEY");
        ContentModerationService service = ContentModerationExample.createModerationService(apiKey);

        ModerationResult result = service.moderateText("今天天气真好");

        assertTrue(result.isAllowed());
        assertTrue(result.getCategory() == ContentModerationExample.ModerationCategory.SAFE);
    }

    @Test
    void should_reject_input_with_sensitive_data() {
        String apiKey = System.getenv("OPENAI_API_KEY");
        ValidationConfig config = InputValidationExample.createDefaultValidationConfig();
        InputValidationService service = InputValidationExample.createValidationService(apiKey, config);

        ValidationResult result = service.validateInput("我的邮箱是 [email protected]");

        assertFalse(result.isValid());
        assertTrue(result.getViolatedRules().contains("no_email"));
    }

    @Test
    void should_apply_output_filter() {
        String output = "我的邮箱是 [email protected]，电话 13800138000";

        FilterConfig config = OutputFilteringExample.createDefaultFilterConfig();
        FilterResult result = OutputFilteringExample.filterOutput(output, config);

        assertFalse(result.getOriginalOutput().equals(result.getFilteredOutput()));
        assertTrue(result.getAppliedRules().size() > 0);
    }

    @Test
    void should_enforce_rate_limit() {
        RateLimitingExample.RateLimiter limiter = new RateLimitingExample.RateLimiter(
            new RateLimitingExample.RateLimitConfig(
                    5,      // 每分钟 5 次
                    10,     // 每小时 10 次
                    100,    // 每天 100 次
                    3       // 突发 3 次
            )
        );

        String userId = "test_user";

        // 前 5 个请求应该被允许
        for (int i = 1; i <= 5; i++) {
            RateLimitingExample.RateLimitResult result = limiter.checkRateLimit(userId);
            assertTrue(result.isAllowed(), "第 " + i + " 个请求应该被允许");
        }

        // 第 6 个请求应该被拒绝
        RateLimitingExample.RateLimitResult result = limiter.checkRateLimit(userId);
        assertFalse(result.isAllowed(), "第 6 个请求应该被拒绝");
        assertEquals("每分钟请求限制", result.getMessage());
    }

    @Test
    void should_reset_rate_limit() {
        RateLimitingExample.RateLimiter limiter = new RateLimitingExample.RateLimiter(
            new RateLimitingExample.RateLimitConfig(
                    3,      // 每分钟 3 次
                    10,     // 每小时 10 次
                    100,    // 每天 100 次
                    2       // 突发 2 次
            )
        );

        String userId = "test_user";

        // 使用所有请求
        for (int i = 0; i < 3; i++) {
            limiter.checkRateLimit(userId);
        }

        // 第 4 个请求应该被拒绝
        RateLimitingExample.RateLimitResult result = limiter.checkRateLimit(userId);
        assertFalse(result.isAllowed());

        // 重置
        limiter.resetUserState(userId);

        // 重置后的请求应该被允许
        result = limiter.checkRateLimit(userId);
        assertTrue(result.isAllowed());
    }
}

实践练习

练习 1：实现多层级审核

import dev.langchain4j.service.AiServices;
import dev.langchain4j.service.SystemMessage;
import dev.langchain4j.model.chat.ChatModel;
import dev.langchain4j.model.openai.OpenAiChatModel;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 多层级审核
 */
public class MultiLevelModeration {

    private static final Logger logger = LoggerFactory.getLogger(MultiLevelModeration.class);

    /**
     * 审核级别
     */
    public enum ModerationLevel {
        LEVEL_1("第一层 - 基础关键词检查"),
        LEVEL_2("第二层 - 语义分析"),
        LEVEL_3("第三层 - 上下文分析"),
        LEVEL_4("第四层 - 专家审核");

        private final String description;

        ModerationLevel(String description) {
            this.description = description;
        }

        public String getDescription() { return description; }
    }

    /**
     * 审核结果
     */
    public static class MultiLevelResult {
        private final ModerationLevel passedAt;
        private final boolean isAllowed;
        private final String reason;
        private final double confidence;
        private final List<ModerationLevel> checkedLevels;

        public MultiLevelResult(ModerationLevel passedAt, boolean isAllowed, 
                            String reason, double confidence, 
                            List<ModerationLevel> checkedLevels) {
            this.passedAt = passedAt;
            this.isAllowed = isAllowed;
            this.reason = reason;
            this.confidence = confidence;
            this.checkedLevels = checkedLevels;
        }

        public ModerationLevel getPassedAt() { return passedAt; }
        public boolean isAllowed() { return isAllowed; }
        public String getReason() { return reason; }
        public double getConfidence() { return confidence; }
        public List<ModerationLevel> getCheckedLevels() { return checkedLevels; }
    }

    /**
     * 多层级审核服务
     */
    @AiService
    public interface MultiLevelModerationService {
        /**
         * 执行多层级审核
         */
        MultiLevelResult performModeration(String text);
    }

    /**
     * 创建多层级审核服务
     */
    public static MultiLevelModerationService createMultiLevelModerationService(String apiKey) {
        return AiServices.builder(MultiLevelModerationService.class)
                .chatModel(OpenAiChatModel.builder()
                        .apiKey(apiKey)
                        .modelName("gpt-4o-mini")
                        .build())
                .systemMessageProvider(chatMemoryId -> 
                    "你是一个多层级内容审核专家。" +
                    "你的任务是按照指定的层级顺序，对给定的文本进行审核。" +
                    "\n第一层审核（LEVEL_1 - 基础关键词检查）：" +
                    "快速检查文本中是否包含明显的违规关键词。" +
                    "如果有，直接拒绝，停止后续审核。" +
                    "\n第二层审核（LEVEL_2 - 语义分析）：" +
                    "分析文本的语义，判断其意图和含义是否安全。" +
                    "即使没有明显关键词，也要判断文本整体语境。" +
                    "\n第三层审核（LEVEL_3 - 上下文分析）：" +
                    "结合文本的上下文信息（如对话历史）进行判断。" +
                    "考虑文本的潜在隐含意义和可能的影响。" +
                    "\n第四层审核（LEVEL_4 - 专家审核）：" +
                    "对于复杂的边缘情况，进行深入的人工专家级分析。" +
                    "综合考虑所有因素，做出最终判断。" +
                    "\n请以 JSON 格式返回结果，包含：" +
                    "- passedAt: 通过审核的最低级别（LEVEL_1、LEVEL_2、LEVEL_3、LEVEL_4 或 FAILED）" +
                    "- isAllowed: 内容是否被允许" +
                    "- reason: 审核结果的简要说明" +
                    "- confidence: 审核确信度（0.0 到 1.0）" +
                    "- checkedLevels: 实际检查的所有级别列表"
                )
                .build();
    }

    /**
     * 执行审核
     */
    public static MultiLevelResult performModeration(String text, String apiKey) {
        MultiLevelModerationService service = createMultiLevelModerationService(apiKey);
        return service.performModeration(text);
    }

    public static void main(String[] args) {
        String apiKey = System.getenv("OPENAI_API_KEY");

        // 测试安全内容
        String safeText = "请问今天天气如何？";
        MultiLevelResult result1 = performModeration(safeText, apiKey);
        System.out.println("╔═════════════════════════════════════════════════════════════╗");
        System.out.println("║              多层级审核示例                              ║");
        System.out.println("╠═══════════════════════════════════════════════════════════╣");
        System.out.println("║ 输入: " + safeText);
        System.out.println("╠═══════════════════════════════════════════════════════════╣");
        System.out.println("║ 审核级别: " + result1.getPassedAt().getDescription());
        System.out.println("║ 是否允许: " + (result1.isAllowed() ? "✅ 允许" : "❌ 拒绝"));
        System.out.println("║ 原因: " + result1.getReason());
        System.out.println("║ 确信度: " + String.format("%.2f", result1.getConfidence()));
        System.out.println("║ 检查级别: " + result1.getCheckedLevels());
        System.out.println("╚═══════════════════════════════════════════════════════════════════════╝");
        System.out.println();

        // 测试有害内容
        String harmfulText = "我讨厌所有人，我要报复他们，毁灭这个世界！";
        MultiLevelResult result2 = performModeration(harmfulText, apiKey);
        System.out.println("╔═════════════════════════════════════════════════════════════╗");
        System.out.println("║              多层级审核示例                              ║");
        System.out.println("╠═══════════════════════════════════════════════════════════╣");
        System.out.println("║ 输入: " + harmfulText);
        System.out.println("╠═════════════════════════════════════════════════════════════╣");
        System.out.println("║ 审核级别: " + result2.getPassedAt().getDescription());
        System.out.println("║ 是否允许: " + (result2.isAllowed() ? "✅ 允许" : "❌ 拒绝"));
        System.out.println("║ 原因: " + result2.getReason());
        System.out.println("║ 确信度: " + String.format("%.2f", result2.getConfidence()));
        System.out.println("║ 检查级别: " + result2.getCheckedLevels());
        System.out.println("╠─────────────────────────────────────────────────────────────╣");
        System.out.println("║ 审核详情:                                               ║");
        System.out.println("║ LEVEL_1: 基础关键词检查 - 检测到违规关键词               ║");
        System.out.println("║           仇恨言论、暴力内容                                 ║");
        System.out.println("║ LEVEL_2: 语义分析 - 文本表达了敌对情绪               ║");
        System.out.println("║           具有攻击性和威胁意图                               ║");
        System.out.println("║ LEVEL_3: 上下文分析 - 分析对话和场景             ║");
        System.out.println("║           明显的威胁和危险意图                               ║");
        System.out.println("║ LEVEL_4: 专家审核 - 专家判断                       ║");
        System.out.println("║           高风险，建议拒绝                                 ║");
        System.out.println("╠─────────────────────────────────────────────────────────────╣");
        System.out.println("║ 最终判断: 拒绝                                         ║");
        System.out.println("║ 原因: 内容包含多个违规关键词和敌对意图，属于高风险内容       ║");
        System.out.println("║ 建议: 立即阻止用户，并记录安全事件                       ║");
        System.out.println("╠─────────────────────────────────────────────────────────────╣");
        System.out.println("║ 审核级别: LEVEL_1                                        ║");
        System.out.println("║ 确信度: 0.95                                               ║");
        System.out.println("║ 检查级别: [LEVEL_1, LEVEL_2, LEVEL_3, LEVEL_4]            ║");
        System.out.println("╚═══════════════════════════════════════════════════════════════════════════════════╝");
    }
}

总结

本章要点

安全护栏重要性
- 防止有害内容
- 保护用户隐私
- 确保合规要求
- 维护品牌形象
审核类型
- 内容审核
- 输入验证
- 输出过滤
- 速率限制
实现方式
- 基于规则（关键词、正则表达式）
- 基于模型（语义分析）
- 混合方法（规则 + 模型）
- 多层级审核
最佳实践
- 立即阻止明显违规
- 使用多层审核提高准确度
- 记录所有安全事件
- 定期审查和更新政策
- 提供清晰的反馈
应用场景
- 社交媒体平台
- 即时通讯应用
- 用户生成内容平台
- 教育和儿童应用
- 金融和医疗应用

下一步

在下一章节中，我们将学习：

其他模型提供商
自定义模型集成
本地模型部署
性能优化技巧
生产环境部署

常见问题

Q1：如何平衡安全性和用户体验？ A：平衡策略：

第一层快速检查避免明显违规
第二层语义分析减少误报
对可疑内容使用人工审核
提供清晰的政策说明
允许用户申诉

Q2：如何检测隐含的违规内容？ A：检测方法：

语义分析识别意图
上下文分析了解场景
情感分析判断语气
隐喻和讽刺识别
多模型交叉验证

Q3：如何处理多语言内容审核？ A：处理策略：

使用多语言审核模型
翻译后审核（成本高）
针对每种语言制定规则
使用通用语义模型
组合多种方法

Q4：如何减少误报？ A：减少策略：

调整审核阈值
使用上下文信息
允许用户申诉
人工审核边缘案例
定期审核和更新规则

Q5：如何监控安全护栏效果？ A：监控指标：

违规内容拦截率
误报率和假阴性率
审核时间和延迟
用户投诉率
安全事件趋势

参考资料

版权归属于 LangChat Team
官网：https://langchat.cn

关于

基础入门

核心概念

高级功能

工程实践

生产部署

高级主题

安全护栏

22 - 安全护栏

版本说明

学习目标

前置知识

核心概念

什么是安全护栏？

为什么需要安全护栏？

基础安全护栏

内容审核

输入验证

输入过滤

输出过滤

输出审核

速率限制

请求限流

综合安全系统

完整的安全护栏

测试代码示例

实践练习

练习 1：实现多层级审核

总结

本章要点

下一步

常见问题

参考资料

关于

基础入门

核心概念

高级功能

工程实践

生产部署

高级主题

​22 - 安全护栏

​版本说明

​学习目标

​前置知识

​核心概念

​什么是安全护栏？

​为什么需要安全护栏？

​基础安全护栏

​内容审核

​输入验证

​输入过滤

​输出过滤

​输出审核

​速率限制

​请求限流

​综合安全系统

​完整的安全护栏

​测试代码示例

​实践练习

​练习 1：实现多层级审核

​总结

​本章要点

​下一步

​常见问题

​参考资料

22 - 安全护栏

版本说明

学习目标

前置知识

核心概念

什么是安全护栏？

为什么需要安全护栏？

基础安全护栏

内容审核

输入验证

输入过滤

输出过滤

输出审核

速率限制

请求限流

综合安全系统

完整的安全护栏

测试代码示例

实践练习

练习 1：实现多层级审核

总结

本章要点

下一步

常见问题

参考资料