springboot + 统一返回json数据 + 统一异常处理

迈不过友情╰ 2024-03-16 10:26 127阅读 0赞

### 环境 ###

#### 1、创建一个springboot项目 ####

*  只需引入web依赖即可

![在这里插入图片描述][6c496d270669418d87f8f807bb6a9ff9.png]

*  pom.xml文件

<dependencies>
         <dependency>
              <groupId>org.springframework.boot</groupId>
              <artifactId>spring-boot-starter-web</artifactId>
          </dependency>
    </dependencies>

#### 2、简单的配置 ####

# 应用名称
    spring.application.name=res_exc_demo
    # 端口号
    server.port=8099

### 统一返回 ###

#### 1、定义一个类，返回固定的格式 ####

一般格式包括

*  状态码
 *  状态码信息
 *  具体返回数据

public class Resp<T> {
        
    
        //状态码
        private int code = 200;
        //状态码信息
        private String msg = "success";
        //返回的信息
        private T data;
    
        private Resp(int code,String msg,T data){
        
            this.code = code;
            this.msg = msg;
            this.data = data;
        }
    
        public static <T> Resp success(T data){
        
            Resp resp = new Resp(200, "success", data);
            return resp;
        }
    
        public static <T> Resp success(String msg,T data){
        
            Resp resp = new Resp(200,msg, data);
            return resp;
        }
    
        public static <T> Resp error(AppExceptionCodeMsg appExceptionCodeMsg){
        
            Resp resp = new Resp(appExceptionCodeMsg.getCode(), appExceptionCodeMsg.getMsg(), null);
            return resp;
        }
        public static <T> Resp error(int code,String msg){
        
            Resp resp = new Resp(code,msg, null);
            return resp;
        }
    
        public int getCode() {
        
            return code;
        }
    
        public String getMsg() {
        
            return msg;
        }
    
        public T getData() {
        
            return data;
        }
    
    }

#### 2、controller统一返回 ####

@RestController
    public class DemoController {
        
    
        @GetMapping("demo")
        public Resp<String> demo1(String name){
        
        	//...
           return Resp.success("default");
        }
    }

### 统一异常处理 ###

#### 1、创建一个枚举类型 ####

存储各种类型的异常状态码和信息

package com.pzz.exce;
    
    /**
     * 枚举类，所有自定义异常的状态码和信息
     */
    //这个枚举类中定义的都是跟业务有关的异常
    public enum AppExceptionCodeMsg {
        
    
        INVALID_CODE(10000,"验证码无效"),
        USERNAME_NOT_EXISTS(10001,"用户名不存在"),
        USER_CREDIT_NOT_ENOUTH(10002,"用户积分不足");
    
        private int code ;
        private String msg ;
    
        public int getCode() {
        
            return code;
        }
    
        public String getMsg() {
        
            return msg;
        }
    
    
        AppExceptionCodeMsg(int code, String msg){
        
            this.code = code;
            this.msg = msg;
        }
    
    }

#### 2、创建自定义的异常类 ####

package com.pzz.exce;
    
    public class AppException extends RuntimeException{
        
    
        private int code = 500;
        private String msg = "服务器异常";
    
    
        public AppException(AppExceptionCodeMsg appExceptionCodeMsg){
        
            super();
            this.code = appExceptionCodeMsg.getCode();
            this.msg = appExceptionCodeMsg.getMsg();
    
        }
    
        public AppException(int code,String msg){
        
            super();
            this.code = code;
            this.msg = msg;
    
        }
    
        public int getCode() {
        
            return code;
        }
    
        public String getMsg() {
        
            return msg;
        }
    
    }

#### 3、创建全局统一异常处理类 ####

package com.pzz.exce;
    
    import com.pzz.resp.Resp;
    import org.springframework.web.bind.annotation.ControllerAdvice;
    import org.springframework.web.bind.annotation.ExceptionHandler;
    import org.springframework.web.bind.annotation.ResponseBody;
    
    /**
     * 全局异常
     */
    @ControllerAdvice
    public class GlobalExceptionHandler {
        
    
    
        @ExceptionHandler(value = {
        Exception.class})
        @ResponseBody
        public <T> Resp<T> exceptionHandler(Exception e){
        
            //这里先判断拦截到的Exception是不是我们自定义的异常类型
            if(e instanceof AppException){
        
                AppException appException = (AppException)e;
                return Resp.error(appException.getCode(),appException.getMsg());
            }
    
            //如果拦截的异常不是我们自定义的异常(例如：数据库主键冲突)
            return Resp.error(500,"服务器端异常");
        }
    }

#### 4、controller ####

package com.pzz.controller;
    
    import com.pzz.exce.AppException;
    import com.pzz.exce.AppExceptionCodeMsg;
    import com.pzz.resp.Resp;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.util.Arrays;
    import java.util.List;
    
    @RestController
    public class DemoController {
        
    
    
        @GetMapping("demo")
        public Resp<String> demo1(String name){
        
    
            if("ok".equals(name)){
        
                return Resp.success("succ");
            }
            if("err".equals(name)){
        
                //抛业务相关的异常
                throw new AppException(AppExceptionCodeMsg.USERNAME_NOT_EXISTS);
            }
    
            if("errcode".equals(name)){
        
                throw new AppException(AppExceptionCodeMsg.INVALID_CODE);
            }
            if("0".equals(name)){
        
                int i=1/0;
            }
    
            //检查用户积分是否足够，如果不够，就抛出异常
            if("notenough".equals(name)){
        
                throw new AppException(AppExceptionCodeMsg.USER_CREDIT_NOT_ENOUTH);
            }
    
            return Resp.success("default");
        }
        
       @GetMapping("list")
        public Resp<List> list(){
        
    		List<String> list = Arrays.asList("zhangsan","lisi","wangwu");
    
            return Resp.success(list);
        }
    }

#### 测试效果 ####

![在这里插入图片描述][fe3d3b4464c74db6a89fe329abd8fdff.png]  
![在这里插入图片描述][d90598d95e2f47b58795ab724af73a60.png]

结束！  
hy:6

--------------------

人可以犯错，但是不可犯同一个错。---苏格拉底

[6c496d270669418d87f8f807bb6a9ff9.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/efb971d3eaff47de8a86ef2b30ce7a71.png
[fe3d3b4464c74db6a89fe329abd8fdff.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/af19c758223e4bf396e2e97ee4ed809f.png
[d90598d95e2f47b58795ab724af73a60.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/16/e6d39ace8c1043aebc9edf4f65d43edb.png