Spring Boot Advanced Web Advanced Learning - Unified Exception Handling

1. Create a new return result class result.java

public class Result<T> { 

    //Error code 
    private Integer code; 
    //Prompt information 
    private String msg; 
    //Specific content 
    private T data; 

    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 T getData() { 
        return data; 
    } 

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

2. Custom exception handling class GirlException.java

public class GirlException extends RuntimeException{

    private Integer code;

    public GirlException(ResultEnum resultEnum){
        super(resultEnum.getMsg());
        this.code = resultEnum.getCode();
    }

    public Integer getCode() {
        return code;
    }

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

}

3. The new service GirlService.java throws an exception

public void getAge (Integer id) throws Exception { 
    Girl girl = girlReposistory.findById(id).get(); 
    Integer age = girl.getAge(); 

    if(age<10){ 
       throw new GirlException ( ResultEnum.PRIMARY_SCHOOL ); / /Define enumeration, unified management 
    }else if (age >10 && age <16){ 
        throw new GirlException ( ResultEnum.MIDDLE_SCHOOL ); 
    } 

} 

4. The girlService.getAge(id) method is called in the controller class and an exception is thrown

@GetMapping(value = "/getage/{id}")
public void getAge(@PathVariable("id") Integer id) throws Exception{
    girlService.getAge(id);

}

5.新建 ResultEnum.java枚举

public enum ResultEnum { 
    UNKONW_ERROR(-1,"unknown error"), 
    SUCCESS(0,"success"), 
    PRIMARY_SCHOOL(100,"you may still be in elementary school"), 
    MIDDLE_SCHOOL(101,"you may be in junior high school") 

    ; 


    private Integer code; 
    private String msg; 

    ResultEnum(Integer code, String msg) { 
        this.code = code; 
        this.msg = msg; 
    } 

    public Integer getCode() { 
        return code; 
    } 


    public String getMsg() { 
        return msg; 
    } 


}