文章目录
前言
本篇主要针对前后端分离的项目，做的一个统一响应包装、统一异常捕获处理。
在Spring里，我们可以使用@ControllerAdvice来声明一些关于controller的全局性的东西，其用法主要有以下三点：
1、@ExceptionHandler注解标注的方法：用于捕获Controller中抛出的不同类型的异常，从而达到异常全局处理的目的；
2、@ModelAttribute注解标注的方法：表示此方法会在执行目标Controller方法之前执行；
3、@InitBinder注解标注的方法：用于请求中注册自定义参数的解析，从而达到自定义请求参数格式的目的；
参考：
@ControllerAdvice注解作用及源码解析
@ControllerAdvice 的介绍及三种用法
1、工程包结构
2、POM依赖
xml
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>3、Java代码
AppExceptionCodeMsg
java
//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;
}
}AppException
java
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;
}
}Resp
java
import com.atguigu.boot.exception.AppExceptionCodeMsg;
public class Resp<T> {
//服务端返回的错误码
private int code = 200;
//服务端返回的错误信息
private String msg = "success";
//我们服务端返回的数据
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;
}
}GlobalExceptionHandler
java
import com.atguigu.boot.bean.Resp;
import com.atguigu.boot.exception.AppException;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseBody;
@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");
}
}ExpTestController
java
import com.atguigu.boot.bean.Resp;
import com.atguigu.boot.exception.AppException;
import com.atguigu.boot.exception.AppExceptionCodeMsg;
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 ExpTestController {
@GetMapping("demo")
public Resp<String> demo(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);
}
}