SpringBoot中的添加操作

1.userMapper中定义方法

 //添加操作(返回的是受影响的行数)
    int save(User user);

2.定义一个工具类判断是否为空（其中使用到StringUtil类，需要引入依赖）

public class AssertUtil {
    public static void isTrue(Boolean flag,String msg){
        if(flag){
            throw new ParamException(msg);
        }
    }
}

3.定义一个ResultInfo类

package org.example.springboot.po.vo;

public class ResultInfo {
    private Integer code=200;
    private String msg="操作成功";
    private Object result;

    public Integer getCode() {
        return code;
    }

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

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }

    public Object getResult() {
        return result;
    }

    public void setResult(Object result) {
        this.result = result;
    }
}

4.service层

    /* 添加用户操作*/
    public void saveUser(User user){
        AssertUtil.isTrue(StringUtils.isBlank(user.getUserName()),"用户名为空");
        AssertUtil.isTrue(StringUtils.isBlank(user.getUserPwd()),"密码为空");
        //通过用户名查询对象是否存在
        User temp=userMapper.queryUserByUserName(user.getUserName());
        AssertUtil.isTrue(null!=temp,"用户已经存在");
        AssertUtil.isTrue(userMapper.save(user)<1,"用户添加失败");
    }

5.定义一个异常类

public class ParamException extends RuntimeException{
    private Integer code=300;
    private String msg="参数异常";

    public ParamException(){
        super("参数异常！");
    }

    public ParamException(String msg){
        super(msg);
        this.msg=msg;
    }

    public ParamException(Integer code){
        super("参数异常");
        this.code=code;
    }

    public ParamException(Integer code, String msg) {
        super(msg);
        this.code = code;
        this.msg = msg;
    }

    public Integer getCode() {
        return code;
    }

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

    public String getMsg() {
        return msg;
    }

    public void setMsg(String msg) {
        this.msg = msg;
    }
}

6.controller层

@PutMapping("/user")
    public ResultInfo saveUser(User user){
        ResultInfo resultInfo=new ResultInfo();
        try{
            userService.saveUser(user);
        }catch(ParamException e){
            resultInfo.setCode(e.getCode());
            resultInfo.setResult(e.getMsg());
            e.printStackTrace();
        }catch(Exception e){
            resultInfo.setCode(300);
            resultInfo.setResult("添加失败");
            e.printStackTrace();
        }
        return resultInfo;
    }