java使用泛型定义结果集

介绍

写三个文件ResultsCode.java、ResponseData.java、Result.java，使用泛型让java项目中返回结果集，能够提高代码的可读性、可维护性和可扩展性

代码

ResultsCode.java：

package com.rds.study.pojo;

public enum ResultsCode {
    SUCCESS(200, "操作成功"),
    ERROR(500, "服务器异常"),
    UNAUTHORIZED(401, "未认证（签名错误）"),
    NOT_FOUNT(404, "接口不存在");

    public int code;
    public String message;

    ResultsCode(int code, String message) {
        this.code = code;
        this.message = message;
    }
}

ResponseData.java：

package com.rds.study.pojo;

public class ResponseData {
    public static <T> Result<T> success(T info) {
        return new Result<T>()
                .setCode(ResultsCode.SUCCESS.code)
                .setMsg(ResultsCode.SUCCESS.message)
                .setInfo(info);
    }

    public static Result success() {
        return new Result();
    }

    public static Result error() {
        return error(ResultsCode.ERROR.message); // 输出定义好的errormessage
    }

    public static Result error(String message) { // 输出自己想输出的errormessage
        return new Result()
                .setCode(ResultsCode.ERROR)
                .setMsg(message);
    }
}

Result.java：

package com.rds.study.pojo;

import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

@ApiModel
public class Result<T> implements Serializable {
    private static final long serialVersionUID = 1L;
    private final Map<String, Object> map = new HashMap<>();

    @ApiModelProperty(value = "状态码")
    public int code; // 状态码
    @ApiModelProperty(value = "信息")
    private String msg; // 信息
    @ApiModelProperty(value = "对象")
    private T info; // 对象

    public Result(){
        this.code = ResultsCode.SUCCESS.code;
        this.msg = ResultsCode.SUCCESS.message;
    }

    public int getCode() {
        return code;
    }

    public Result<T> setCode(int code) {
        this.code = code;
        return this;
    }

    public Result<T> setCode(ResultsCode resultsCode) {
        this.code = resultsCode.code;
        return this;
    }

    public String getMsg() {
        return msg;
    }

    public Result<T> setMsg(String msg) {
        this.msg = msg;
        return this;
    }

    public Result<T> setMsg(ResultsCode resultsCode) {
        this.msg = resultsCode.message;
        return this;
    }


    public T getInfo() {
        return info;
    }

    public Result<T> setInfo(T info) {
        this.info = info;
        return this;
    }

    public Result<T> putDataValue(String key, Object value) {
        map.put(key, value);
        this.info = (T) map;
        return this;
    }

    @Override
    public String toString() {
        return "{" +
                "code = " +
                " , msg = " +
                " , info = " +
                info +
                "}";
    }
}

这样controller里方法返回成功后，直接return ResponseData.success(T)即可