fix: 脱敏多模态图片请求日志

- 隐去图片 Data URI 编码正文并保留 MIME 与长度

- 补充日志脱敏和 image_url 序列化测试

easy-agents-core/src/main/java/com/easyagents/core/model/chat/log/ChatLogSanitizer.java

@@ -0,0 +1,72 @@
+/*
+ *  Copyright (c) 2023-2026, Easy-Agents (fuhai999@gmail.com).
+ *  <p>
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ */
+package com.easyagents.core.model.chat.log;
+
+/**
+ * 清理聊天请求日志中的大体积或敏感媒体内容。
+ */
+final class ChatLogSanitizer {
+
+    private static final String DATA_URI_PREFIX = "data:image/";
+    private static final String BASE64_MARKER = ";base64,";
+
+    private ChatLogSanitizer() {
+    }
+
+    /**
+     * 隐去图片 Data URI 的编码正文，仅保留 MIME 和字符长度。
+     *
+     * @param message 原始日志消息
+     * @return 脱敏后的日志消息
+     */
+    static String redactImageDataUris(String message) {
+        if (message == null || message.indexOf(DATA_URI_PREFIX) < 0) {
+            return message;
+        }
+
+        StringBuilder sanitized = new StringBuilder(message.length());
+        int cursor = 0;
+        while (cursor < message.length()) {
+            int dataUriStart = message.indexOf(DATA_URI_PREFIX, cursor);
+            if (dataUriStart < 0) {
+                sanitized.append(message, cursor, message.length());
+                break;
+            }
+            int base64Marker = message.indexOf(BASE64_MARKER, dataUriStart);
+            if (base64Marker < 0) {
+                sanitized.append(message, cursor, message.length());
+                break;
+            }
+            int payloadStart = base64Marker + BASE64_MARKER.length();
+            int payloadEnd = payloadStart;
+            while (payloadEnd < message.length() && isBase64Character(message.charAt(payloadEnd))) {
+                payloadEnd++;
+            }
+
+            sanitized.append(message, cursor, payloadStart);
+            sanitized.append("<已脱敏，编码长度=").append(payloadEnd - payloadStart).append('>');
+            cursor = payloadEnd;
+        }
+        return sanitized.toString();
+    }
+
+    /**
+     * 判断字符是否可能属于 Base64 正文。
+     *
+     * @param value 待判断字符
+     * @return 是否属于 Base64 字符集
+     */
+    private static boolean isBase64Character(char value) {
+        return value >= 'A' && value <= 'Z'
+                || value >= 'a' && value <= 'z'
+                || value >= '0' && value <= '9'
+                || value == '+'
+                || value == '/'
+                || value == '='
+                || value == '-'
+                || value == '_';
+    }
+}

easy-agents-core/src/main/java/com/easyagents/core/model/chat/log/DefaultChatMessageLogger.java

@@ -36,7 +36,8 @@ public class DefaultChatMessageLogger implements IChatMessageLogger {
         if (shouldLog(config)) {
             String provider = getProviderName(config);
             String model = getModelName(config);
-            logConsumer.accept(String.format("[%s/%s] >>>> request: %s", provider, model, message));
+            logConsumer.accept(String.format("[%s/%s] >>>> request: %s",
+                    provider, model, ChatLogSanitizer.redactImageDataUris(message)));
         }
     }
 

easy-agents-core/src/test/java/com/easyagents/core/model/chat/log/DefaultChatMessageLoggerTest.java

@@ -0,0 +1,32 @@
+package com.easyagents.core.model.chat.log;
+
+import com.easyagents.core.model.chat.ChatConfig;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.concurrent.atomic.AtomicReference;
+
+/**
+ * 默认聊天日志记录器测试。
+ */
+public class DefaultChatMessageLoggerTest {
+
+    /**
+     * 验证请求日志不会输出完整图片 Base64。
+     */
+    @Test
+    public void shouldRedactImageDataUriPayload() {
+        AtomicReference<String> logged = new AtomicReference<>();
+        DefaultChatMessageLogger logger = new DefaultChatMessageLogger(logged::set);
+        ChatConfig config = new ChatConfig();
+        config.setProvider("test");
+        config.setModel("vision");
+
+        logger.logRequest(config,
+                "{\"url\":\"data:image/png;base64,AQIDBA==\",\"text\":\"ok\"}");
+
+        Assert.assertNotNull(logged.get());
+        Assert.assertTrue(logged.get().contains("data:image/png;base64,<已脱敏，编码长度=8>"));
+        Assert.assertFalse(logged.get().contains("AQIDBA=="));
+    }
+}

easy-agents-core/src/test/java/com/easyagents/core/test/model/client/OpenAIChatMessageSerializerTest.java

@@ -0,0 +1,36 @@
+package com.easyagents.core.test.model.client;
+
+import com.easyagents.core.message.UserMessage;
+import com.easyagents.core.model.chat.ChatConfig;
+import com.easyagents.core.model.client.OpenAIChatMessageSerializer;
+import org.junit.Assert;
+import org.junit.Test;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * OpenAI-compatible 多模态消息序列化测试。
+ */
+public class OpenAIChatMessageSerializerTest {
+
+    /**
+     * 验证 Data URI 会写入标准的 image_url.url 字段。
+     */
+    @Test
+    public void shouldSerializeImageDataUriIntoImageUrlField() {
+        String dataUri = "data:image/png;base64,AQID";
+        UserMessage message = new UserMessage("识别图片");
+        message.addImageUrl(dataUri);
+
+        List<Map<String, Object>> messages = new OpenAIChatMessageSerializer()
+                .serializeMessages(List.of(message), new ChatConfig());
+
+        Assert.assertNotNull(messages);
+        List<?> content = (List<?>) messages.get(0).get("content");
+        Map<?, ?> imageContent = (Map<?, ?>) content.get(1);
+        Map<?, ?> imageUrl = (Map<?, ?>) imageContent.get("image_url");
+        Assert.assertEquals("image_url", imageContent.get("type"));
+        Assert.assertEquals(dataUri, imageUrl.get("url"));
+    }
+}