From 94423833dcaf85f710a1bb627d1f95f0c8b293ae Mon Sep 17 00:00:00 2001
From: zhuangtianxiang <2913129173@qq.com>
Date: Mon, 9 Dec 2024 16:41:47 +0800
Subject: [PATCH] =?UTF-8?q?feat(gateway):=20=E6=B7=BB=E5=8A=A0=E5=85=A8?=
 =?UTF-8?q?=E5=B1=80=E5=93=8D=E5=BA=94=E5=A4=84=E7=90=86=E5=99=A8=E5=92=8C?=
 =?UTF-8?q?=E7=BB=9F=E4=B8=80=E8=BF=94=E5=9B=9E=E7=BB=93=E6=9E=9C=E5=B0=81?=
 =?UTF-8?q?=E8=A3=85?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

- 新增 GlobalResponseHandler 类实现全局响应处理
- 添加 Result 类用于统一返回结果封装
- 实现 JsonUtil 工具类用于对象与 JSON 字符串转换
-优化了返回类型为 String 时的处理逻辑
---
 .../response/GlobalResponseHandler.java       | 65 +++++++++++++++++++
 .../gateway/framework/response/JsonUtil.java  | 26 ++++++++
 .../gateway/framework/response/Result.java    | 51 +++++++++++++++
 3 files changed, 142 insertions(+)
 create mode 100644 src/main/java/com/zsc/edu/gateway/framework/response/GlobalResponseHandler.java
 create mode 100644 src/main/java/com/zsc/edu/gateway/framework/response/JsonUtil.java
 create mode 100644 src/main/java/com/zsc/edu/gateway/framework/response/Result.java

diff --git a/src/main/java/com/zsc/edu/gateway/framework/response/GlobalResponseHandler.java b/src/main/java/com/zsc/edu/gateway/framework/response/GlobalResponseHandler.java
new file mode 100644
index 0000000..dffbca2
--- /dev/null
+++ b/src/main/java/com/zsc/edu/gateway/framework/response/GlobalResponseHandler.java
@@ -0,0 +1,65 @@
+package com.zsc.edu.gateway.framework.response;
+
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.core.MethodParameter;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.http.converter.HttpMessageConverter;
+import org.springframework.http.server.ServerHttpRequest;
+import org.springframework.http.server.ServerHttpResponse;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+import org.springframework.web.servlet.mvc.method.annotation.ResponseBodyAdvice;
+
+/**
+ * 响应统一封装
+ * <p>
+ * 将响应数据，封装成统一的数据格式。
+ * <p>
+ * 通过本处理器，将接口方法返回的数据，统一封装到 Result 的 data 字段中，如果接口方法返回为 void，则 data 字段的值为 null。
+ *
+ * @author zhuang
+ */
+@Slf4j
+@RestControllerAdvice(basePackages = "com.example.web")
+public class GlobalResponseHandler implements ResponseBodyAdvice<Object> {
+
+    /**
+     * 此组件是否支持给定的控制器方法返回类型和选定的 {@code HttpMessageConverter} 类型。
+     *
+     * @return 如果应该调用 {@link #beforeBodyWrite} ，则为 {@code true}；否则为false。
+     */
+    @Override
+    public boolean supports(MethodParameter returnType, Class<? extends HttpMessageConverter<?>> converterType) {
+        // 返回类型不为Result，才需要封装
+        return returnType.getParameterType() != Result.class;
+    }
+
+
+    /**
+     * 统一封装返回响应数据
+     */
+    @Override
+    public Object beforeBodyWrite(Object body, MethodParameter returnType, MediaType selectedContentType,
+                                  Class<? extends HttpMessageConverter<?>> selectedConverterType, ServerHttpRequest request,
+                                  ServerHttpResponse response) {
+
+        // 数据封装为Result：将接口方法返回的数据，封装到 Result.data 字段中。
+        Result<Object> result = Result.success(body);
+
+        // 返回类型不是 String：直接返回
+        if (returnType.getParameterType() != String.class) {
+            return result;
+        }
+
+        // 返回类型是 String：不能直接返回，需要进行额外处理
+        // 1. 将 Content-Type 设为 application/json ；返回类型是String时，默认 Content-Type = text/plain
+        HttpHeaders headers = response.getHeaders();
+        headers.setContentType(MediaType.APPLICATION_JSON);
+        // 2. 将 Result 转为 Json字符串 再返回
+        // （否则会报错 java.lang.ClassCastException: com.example.core.model.Result cannot be cast to java.lang.String）
+        return JsonUtil.toJson(result);
+    }
+
+}
+
diff --git a/src/main/java/com/zsc/edu/gateway/framework/response/JsonUtil.java b/src/main/java/com/zsc/edu/gateway/framework/response/JsonUtil.java
new file mode 100644
index 0000000..0d7fbbc
--- /dev/null
+++ b/src/main/java/com/zsc/edu/gateway/framework/response/JsonUtil.java
@@ -0,0 +1,26 @@
+package com.zsc.edu.gateway.framework.response;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+/**
+ * @author zhuang
+ */
+public class JsonUtil {
+
+    private static final ObjectMapper objectMapper = new ObjectMapper();
+
+    /**
+     * 将对象转换为 JSON 字符串
+     *
+     * @param obj 需要转换的对象
+     * @return JSON 字符串
+     */
+    public static String toJson(Object obj) {
+        try {
+            return objectMapper.writeValueAsString(obj);
+        } catch (JsonProcessingException e) {
+            throw new RuntimeException("Failed to convert object to JSON", e);
+        }
+    }
+}
diff --git a/src/main/java/com/zsc/edu/gateway/framework/response/Result.java b/src/main/java/com/zsc/edu/gateway/framework/response/Result.java
new file mode 100644
index 0000000..c571a03
--- /dev/null
+++ b/src/main/java/com/zsc/edu/gateway/framework/response/Result.java
@@ -0,0 +1,51 @@
+package com.zsc.edu.gateway.framework.response;
+
+import lombok.*;
+
+/**
+ * 返回响应，统一封装实体
+ *
+ * @param <T> 数据实体泛型
+ * @author zhuang
+ */
+@Getter
+@ToString
+@EqualsAndHashCode
+@AllArgsConstructor(access = AccessLevel.PRIVATE)
+public class Result<T> {
+
+    private String userMessage;
+
+    /**
+     * 错误码<br>
+     * 调用成功时，为 null。<br>
+     * 示例：A0211
+     */
+    private String errorCode;
+
+    /**
+     * 错误信息<br>
+     * 调用成功时，为 null。<br>
+     * 示例："用户输入密码错误次数超限"
+     */
+    private String errorMessage;
+
+    /**
+     * 数据实体（泛型）<br>
+     * 当接口没有返回数据时，为 null。
+     */
+    private T data;
+
+
+    public static <T> Result<T> success(T data) {
+        return new Result<>("操作成功！", null, null, data);
+    }
+
+
+    public static <T> Result<T> fail(String userMessage, String errorCode, String errorMessage) {
+        return new Result<>(userMessage, errorCode, errorMessage, null);
+    }
+
+}
+
+