前言

相关jar依赖引入

<!-- Spring Boot 启动父依赖 -->
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.6.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
</properties>

<dependencies>
    <!-- Spring Boot Web 依赖 -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
</dependencies>

全局异常控制器

package com.yb.demo.common.handler;

import com.yb.demo.common.enums.CodeEnum;
import com.yb.demo.common.exception.BizException;
import com.yb.demo.pojo.response.Result;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.springframework.validation.BindException;
import org.springframework.web.HttpRequestMethodNotSupportedException;
import org.springframework.web.bind.MethodArgumentNotValidException;
import org.springframework.web.bind.MissingServletRequestParameterException;
import org.springframework.web.bind.annotation.ExceptionHandler;
import org.springframework.web.bind.annotation.RestControllerAdvice;

import javax.validation.ValidationException;
import java.util.StringJoiner;

/**
 * 全局异常处理
 * <p>
 * 规范：流程跳转尽量避免使用抛 BizException 来做控制。
 *
 * @author daoshenzzg@163.com
 * @date 2019-09-06 18:02
 */
@Slf4j
@RestControllerAdvice
public class GlobalExceptionHandler {

    /**
     * 处理自定义异常
     *
     * @param ex
     * @return
     */
    @ExceptionHandler(BizException.class)
    public Result handleBizException(BizException ex) {
        Result result = Result.renderErr(ex.getCode());
        if (StringUtils.isNotBlank(ex.getRemark())) {
            result.withRemark(ex.getRemark());
        }
        return result;
    }

    /**
     * 参数绑定错误
     *
     * @param ex
     * @return
     */
    @ExceptionHandler(BindException.class)
    public Result handleBindException(BindException ex) {
        StringJoiner sj = new StringJoiner(";");
        ex.getBindingResult().getFieldErrors().forEach(x -> sj.add(x.getDefaultMessage()));
        return Result.renderErr(CodeEnum.REQUEST_ERR).withRemark(sj.toString());
    }

    /**
     * 参数校验错误
     *
     * @param ex
     * @return
     */
    @ExceptionHandler(ValidationException.class)
    public Result handleValidationException(ValidationException ex) {
        return Result.renderErr(CodeEnum.REQUEST_ERR).withRemark(ex.getCause().getMessage());
    }

    /**
     * 字段校验不通过异常
     *
     * @param ex
     * @return
     */
    @ExceptionHandler(MethodArgumentNotValidException.class)
    public Result handleMethodArgumentNotValidException(MethodArgumentNotValidException ex) {
        StringJoiner sj = new StringJoiner(";");
        ex.getBindingResult().getFieldErrors().forEach(x -> sj.add(x.getDefaultMessage()));
        return Result.renderErr(CodeEnum.REQUEST_ERR).withRemark(sj.toString());
    }

    /**
     * Controller参数绑定错误
     *
     * @param ex
     * @return
     */
    @ExceptionHandler(MissingServletRequestParameterException.class)
    public Result handleMissingServletRequestParameterException(MissingServletRequestParameterException ex) {
        return Result.renderErr(CodeEnum.REQUEST_ERR).withRemark(ex.getMessage());
    }

    /**
     * 处理方法不支持异常
     *
     * @param ex
     * @return
     */
    @ExceptionHandler(value = HttpRequestMethodNotSupportedException.class)
    public Result handleHttpRequestMethodNotSupportedException(HttpRequestMethodNotSupportedException ex) {
        return Result.renderErr(CodeEnum.METHOD_NOT_ALLOWED);
    }

    /**
     * 其他未知异常
     *
     * @param ex
     * @return
     */
    @ExceptionHandler(value = Exception.class)
    public Result handleException(Exception ex) {
        log.error(ex.getMessage(), ex);
        return Result.renderErr(CodeEnum.SERVER_ERR);
    }
}

个性化异常处理

自定义异常

/**
 * 业务异常跳转。
 *
 * @author daoshenzzg@163.com
 * @date 2019-09-09 14:57
 */
@Data
public class BizException extends RuntimeException {
    private static final long serialVersionUID = 1L;

    private CodeEnum code;
    private String remark;

    public BizException(CodeEnum code) {
        super(code.getMessage());
        this.code = code;
    }

    public BizException withRemark(String remark) {
        this.remark = remark;
        return this;
    }
}

/**
     * 添加学生
     *
     * @param student
     * @return
     */
    public Student1DO addStudent(Student1DO student) {
        if (StringUtils.isNotBlank(student.getStudName())) {
            // 举例扔个业务异常，实际使用过程中，应该避免扔异常
            throw new BizException(CodeEnum.REQUEST_ERR).withRemark("studName不能为空");
        }
        student1Mapper.insert(student);
        return student;
    }

{
    "code": -400,
    "msg": "请求错误(studName不能为空)",
    "data": {},
    "ttl": 0
}

使用 Spring validation 完成数据后端校验

package com.yb.demo.pojo.model.db1;

import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableName;
import lombok.Data;

import javax.validation.constraints.Min;
import javax.validation.constraints.Size;

/**
 * @author daoshenzzg@163.com
 * @date 2019-08-05 17:58
 */
@Data
@TableName("student")
public class Student1DO {
    private Long id;
    @Size(max = 8, message = "studName长度不能超过8")
    private String studName;
    @Min(value = 12, message = "年龄不能低于12岁")
    private Integer studAge;
    private String studSex;
    @TableField(fill = FieldFill.INSERT)
    private Integer createTime;
    @TableField(fill = FieldFill.INSERT_UPDATE)
    private Integer updateTime;
}

@PostMapping("/student/add")
public Result addStudent(@Validated @RequestBody Student1DO student) {
    student = studentService.addStudent(student);
    return Result.renderOk(student);
}

{
    "code": -400,
    "msg": "请求错误(年龄不能低于12岁)",
    "data": {},
    "ttl": 0
}

结束语

具体代码见：https://github.com/daoshenzzg/springboot2.x-example

本系列文章

• springboot2.x Jackson自定义序列化，优雅实现String、List、Object返回""、[]、{}
• springboot2.x 集成 Mybatis plus(多数据源)，提升20%的开发效率
• springboot2.x 全局异常处理正确方式
• springboot2.x 如何优雅的实现API输出？
• 如何优雅的实现数据置顶、置尾、交换、拖动排序？