统一结果返回

接口(常量)版

　　ResultCode.java

public interface ResultCode {
    Integer SUCCESS = 20000;
    Integer ERROR = 20001;
}

　　R.java

@Data      //lombok
public class R {
    @ApiModelProperty(value = "是否成功")   //swagger
    private Boolean success;

    @ApiModelProperty(value = "返回码")
    private Integer code;

    @ApiModelProperty(value = "返回消息")
    private String message;

    @ApiModelProperty(value = "返回数据")
    private Map<String, Object> data = new HashMap<String, Object>();

    private R(){}    //禁止创建对象，只使用静态方法

    //成功静态方法
    public static R ok() {
        R r = new R();
        r.setSuccess(true);
        r.setCode(ResultCode.SUCCESS);
        r.setMessage("成功");
        return r;
    }

    //失败静态方法
    public static R error() {
        R r = new R();
        r.setSuccess(false);
        r.setCode(ResultCode.ERROR);
        r.setMessage("失败");
        return r;
    }

    public R success(Boolean success){
        this.setSuccess(success);
        return this;    
    }      // return this;用于可以使用链式编程，使代码更简洁

    public R message(String message){
        this.setMessage(message);
        return this;
    }

    public R code(Integer code){
        this.setCode(code);
        return this;
    }

    public R data(String key, Object value){
        this.data.put(key, value);
        return this;
    }

    public R data(Map<String, Object> map){
        this.setData(map);
        return this;
    }
}

创建了统一结果返回之后，javaweb的控制器方法返回结果都以R返回，使代码更加规范