springboot做统一格式返回

1. message类。确定返回格式

package com.dbhd.gvs.common.result;

import org.springframework.http.HttpStatus;

public class Message<T> {
    String status;
    //向前端返回的内容
    String message;

    T data;

    public Message() {
    }

    public Message(String status, String message) {
        this.status = status;
        this.message = message;
    }

    public Message(String status, String message, T data) {
        this.data = data;
        this.status = status;
        this.message = message;
    }

    public static <T> Message<T> custom(String status, String message, T data) {
        return new Message(status, message, data);
    }

    public static <T> Message<T> custom(String status, String message) {
        return new Message(status, message);
    }

    public static HttpStatus num2HttpStatus(String code) {
        HttpStatus status = HttpStatus.NOT_FOUND;
        for (HttpStatus httpStatus : HttpStatus.values()) {
            boolean b = Integer.parseInt(code) == httpStatus.value();
            if (b) {
                return httpStatus;
            }
        }
        return status;
    }

    public String getStatus() {
        return status;
    }

    public void setStatus(String status) {
        this.status = status;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public T getData() {
        return data;
    }

    public void setData(T data) {
        this.data = data;
    }
}

2. ResultVo统一返回格式

package com.dbhd.gvs.common.result;

import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;

/**
 * 统一返回格式，错误处理
 *
 * @param <T>
 */
public class ResultVo<T> extends ResponseEntity<Message> {

    public ResultVo(HttpStatus status) {
        super(status);
    }

    public ResultVo(String code, String msg) {
        super(Message.custom(code, msg), Message.num2HttpStatus(code));
    }

    public ResultVo(String code, String msg, T data) {
        super(Message.custom(code, msg, data), Message.num2HttpStatus(code));
    }

    public static <T> ResultVo<T> success(T data) {
        return new ResultVo("200", "成功", data);
    }

    public static <T> ResultVo<T> saveSuccess(T data) {
        return new ResultVo("201", "添加成功", data);
    }

    public static <T> ResultVo<T> failed(T data) {
        return new ResultVo("422", "失败", data);
    }

    public static <T> ResultVo<T> failMsg(String msg) {
        return new ResultVo("422", msg);
    }

    public static <T> ResultVo<T> custom(String code, String msg, T data) {
        return new ResultVo(code, msg, data);
    }

    public static <T> ResultVo<T> custom(String code, String msg) {
        return new ResultVo(code, msg);
    }

}

3. 不同错误处理,以BadRequestException举例

package com.dbhd.gvs.common.exception;

import lombok.Data;
import lombok.EqualsAndHashCode;
import org.springframework.web.bind.annotation.ResponseBody;

@ResponseBody
@Data
@EqualsAndHashCode(callSuper = true)
public class BadRequestException extends Exception{

    public BadRequestException(String msg) {
        this.msg = msg;
    }

    private final String code = "400";
    private String msg;
}

MyControllerAdvide类处理错误类：

package com.dbhd.gvs.common.exception;

import com.dbhd.gvs.common.result.ResultVo;
import org.springframework.http.HttpStatus;
import org.springframework.validation.BindException;
import org.springframework.validation.BindingResult;
import org.springframework.validation.FieldError;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.ResponseStatus;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import java.util.Objects;

@RestControllerAdvice
public class MyControllerAdvice {

    /**
     * 自定义捕捉异常
     * @param ex
     * @return
     */
    @ExceptionHandler(CustomException.class)
    public ResultVo myErrorHandler(CustomException ex) {
        return ResultVo.custom(ex.getCode(), ex.getMsg());
    }

    /**
     *
     * @param ex
     * @return
     */
    @ExceptionHandler(NotFoundException.class)
    public ResultVo NotFoundException(NotFoundException ex) {
        return ResultVo.custom(ex.getCode(), ex.getMsg());
    }

    @ExceptionHandler(BadRequestException.class)
    public ResultVo BadRequestException(BadRequestException ex) {
        return ResultVo.custom(ex.getCode(), ex.getMsg());
    }

    /**
     * validator注解校验返回 拦截表单参数校验
     * @param ex
     * @return
     */
    @ResponseStatus(HttpStatus.OK)
    @ExceptionHandler({BindException.class})
    public ResultVo bindException(BindException ex) {
        System.out.println("--bindException---");
        BindingResult bindingResult = ex.getBindingResult();
        return ResultVo.custom("400", Objects.requireNonNull(bindingResult.getFieldError()).getDefaultMessage());
    }

    /**
     * validator注解校验返回 拦截JSON参数校验
     * @param ex
     * @return
     */
    @ResponseStatus(HttpStatus.OK)
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public ResultVo bindException(MethodArgumentNotValidException ex) {
        System.out.println("----拦截JSON参数校验-----");
        BindingResult bindingResult = ex.getBindingResult();
        StringBuilder errorMessage = new StringBuilder(bindingResult.getFieldErrors().size() * 16);
//        errorMessage.append("Invalid Request:");
        for (int i = 0; i < bindingResult.getFieldErrors().size(); i++) {
            if (i > 0) {
                errorMessage.append(", ");
            }
            FieldError fieldError = bindingResult.getFieldErrors().get(i);
            errorMessage.append(fieldError.getField());
            errorMessage.append(": ");
            errorMessage.append(fieldError.getDefaultMessage());
        }
        return ResultVo.custom("400", errorMessage.toString());
    }

}

controller使用：

public class CoordinateController {

    @Autowired
    CoordinateService coordinateService;

    @GetMapping
    @ApiOperation("所有坐标列表")
    public ResultVo get() throws Exception {
        List<Coordinate> list = coordinateService.getList();
        return ResultVo.success(list);
    }

serveice使用错误处理：

    @Override
    public Coordinate update(CoordinateDto dto) throws NotFoundException {
        Coordinate coordinate = coordinateDao.getById(dto.getCoordinateId());
        if (coordinate == null) {
            throw new NotFoundException("坐标不存在，可以先添加");
        }
        coordinate.setCoordinate(dto.getCoordinate());
        coordinateDao.update(coordinate);
        return coordinate;
    }