springboot rest controller 统一异常处理，ajax 形式

1. 建立 json 结果类，用于统一显示 json 结果

[code]public class JsonResult<T> {
// code=0表示成功，返回数据data。data!=0，表示错误，返回错误信息msg
private int code;
// 若有错误，data不生成json
@JsonInclude(JsonInclude.Include.NON_NULL)
private T data;
// 若无错误，msg 不生成 json
@JsonInclude(JsonInclude.Include.NON_NULL)
private String msg;

public JsonResult() {
code = 0;
}
public JsonResult<T> ok(T data) {
this.code = 0;
this.data = data;
return this;
}
public JsonResult<T> error(int code, String msg) {
this.code = code;
this.msg = msg;
return this;
}
// getter and setter
}

2. 建立自定义异常类，用于显示自定义的异常

[code]public class CustemerException extends Exception {
public CustemerException(String message) {
super(message);
}
}

3. 建立 rest controller 的异常抓捕类

[code]@RestControllerAdvice
public class JsonExceptionHandler {
@ExceptionHandler(value = Exception.class)
public JsonResult<String> resolveException(HttpServletRequest request, HttpServletResponse response, Exception e) {
JsonResult<String> result = new JsonResult<>();
return result.error(1, e.getMessage());
}
}

4. 在 rest controller的方法中抛出异常

[code]@RestController
public class TestController {
@RequestMapping("/test_error")
public Object testError() throws Exception {
if (true) {
throw new CustemerException("抛出自定义异常");
}
return 1;
}
}

5. 测试，运行项目，打开浏览器输入url

参考：http://www.fengyunxiao.cn