springboot 统一异常处理

由于接口返回的数据格式必须有固定的格式，方便调用者能够对不同异常进行统一的处理。

1.定义一个全局的异常类,继承Exception

public class GlobalException extends Exception{
    private static final long serialVersionUID = -5701182284190108797L;
    private int code;

    public GlobalException(String message) {
        super(message);
    }

    public GlobalException(String message, int code) {
        super(message);
        this.code =code;
    }

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }
}

2.根据自己的需求自定义响应码枚举类

public enum ResponseCode {
    PARAM_ERROR_CODE(400),
    SERVER_ERROR_CODE(500),
    NOT_FIND_ERROR_CODE(404);
    private int code;

    public int getCode() {
        return code;
    }

    public void setCode(int code) {
        this.code = code;
    }

    ResponseCode(int code) {
        this.code = code;
    }
}

3.根据不同的响应码创建相应的异常类

public class ServerException extends GlobalException{
    private static final long serialVersionUID = -1355046108056594333L;
    public ServerException(String message) {
        super(message,ResponseCode.SERVER_ERROR_CODE.getCode());
    }
}

public class ParamException extends GlobalException{
    private static final long serialVersionUID = 6021390821349937519L;

    public ParamException(String message) {
        super(message,ResponseCode.PARAM_ERROR_CODE.getCode());
    }
}

4.定义一个统一的接口返回格式类

public class ResponseData {
    private Boolean status = true;
    private int code = 200;
    private String message;
    private Object data;
    public static ResponseData ok(Object data) {
        return new ResponseData(data);
    }
    public ResponseData(Object data) {
        super();
        this.data = data;
    }
    public ResponseData() {
        super();
    }
    public Boolean getStatus() {
        return status;
    }
    public void setStatus(Boolean status) {
        this.status = status;
    }
    public int getCode() {
        return code;
    }
    public void setCode(int code) {
        this.code = code;
    }
    public String getMessage() {
        return message;
    }
    public void setMessage(String message) {
        this.message = message;
    }
    public Object getData() {
        return data;
    }
    public void setData(Object data) {
        this.data = data;
    }
}

5.定义一个全局异常处理Handler

在这里拦截异常，返回封装的统一的格式

@ControllerAdvice
public class GlobalExceptionHandler {
    @ExceptionHandler(value = GlobalException.class)
    @ResponseBody
    public ResponseData jsonErrorHandler(HttpServletRequest req,GlobalException e){
        ResponseData r = new ResponseData();
        r.setCode(e.getCode());
        r.setData(null);
        r.setMessage(e.getMessage());
        r.setStatus(false);
        return  r;
    }
}

6.模拟使用自定义异常

 @GetMapping("/students/{name}")
    Object queryStudentByName(@PathVariable String name) throws ParamException, ServerException {
        if (name.equals("1")){
            throw  new ParamException("参数错误");
        }
        if (name.equals("2")){
            throw new ServerException("服务器错误");
        }
        return "success";
    }

7.测试