spring boot 统一RESTful风格处理

RESTful 风格规范

1.HTTP 协议的请求动作

动作	说明
GET	在 URL 中传递参数，一般用户定义“查询”功能接口
POST	通过请求体传递参数，一般用于定义实现“查询”和插入功能的接口
PUT	一般用于定义实现“更新”功能的接口
DELETE	一般用于定义“删除”功能的接口

2.HTTP 返回码说明

返回码	说明
200	服务端正确地处理了请求
201	根据(创建数据的)请求以及参数正确地创建对象
301	请求所对应的服务被重定向到其他 URL 地址，此时会进行请求重定向操作
400	服务器不理解请求的语法，一般指参数错误
404	服务器找不到请求的页面
500	服务器遇到错误，无法返回请求
504	网关超时，所以无法返回请求

3.增删改查方法对应的 RESTful 接口名

动作	URL 请求	HTTP 动作	参数说明
查询指定 id 的库存	/stock/{id}	GET	{id}表示带查询的库存数据 id
查询所有库存信息	/stocks	GET	返回所有库存，无需参数
创建新的库存数据	/stock	POST	在请求体(Body)中传入待插入的库存数据
修改指定 id 的库存	/stock/{id}	PUT	{id}表示待修改的库存数据 id,而具体待修改的库存数据会通过请求体(Body)传入
删除指定 id 的库存	/stock/{id}	DELETE	{id}表示待删除的库存数据 id

一般通过/{id}的形式传递参数

RESTful 风格实现

1.HttpCodeEnum 返回码和返回信息

public enum HttpCodeEnum {
    //用枚举的方式定义Http返回码和返回信息
    OK(200, "OK"),
    CREATEOK(201, "CREATEOK"),
    REDIRECT(301, "REDIRECT"),
    PARAM_ERROR(400,"PARAM_ERROR"),
    NOT_FOUND(404, "NOT_FOUND"),
    SERVER_ERROR(500, "SERVER_ERROR");
    //http返回码和返回信息的变量
    private Integer httpCode;
    private String httpMsg;
    //通过构造函数传入http返回码和返回信息
    HttpCodeEnum(Integer code, String msg) {
        this.httpCode = code;
        this.httpMsg = msg;
    }
    public void setHttpCode(Integer httpCode) {
        this.httpCode = httpCode;
    }
    public void setHttpMsg(String httpMsg) {
        this.httpMsg = httpMsg;
    }
    public Integer getHttpCode() {
        return httpCode;
    }
    public String getHttpMsg() {
        return httpMsg;
    }
}

2.HttpReturn 统一返回信息

import java.io.Serializable;

public class HttpReturn  <T> implements Serializable {
    //http返回码
    private Integer httpCode;
    //http返回码对应的信息
    private String httpMsg;
    //返回的数据，用泛型定义
    private T data;

    public Integer getHttpCode() {
        return httpCode;
    }

    public void setHttpCode(Integer httpCode) {
        this.httpCode = httpCode;
    }

    public String getHttpMsg() {
        return httpMsg;
    }

    public void setHttpMsg(String httpMsg) {
        this.httpMsg = httpMsg;
    }

    public T getData() {
        return data;
    }

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

    public HttpReturn(HttpCodeEnum httpCodeEnum, T data) {
        this.httpCode = httpCodeEnum.getHttpCode();
        this.httpMsg = httpCodeEnum.getHttpMsg();
        this.data = data;
    }

    @Override
    public String toString() {
        return "HttpResult{" +
                ", httpCode=" + httpCode +
                ", httpMsg=" + httpMsg +
                ", data='" + data + '\'' +
                '}';
    }

}

3.使用

参数错误

@RequestMapping( value = "/stock/{id}",method = RequestMethod.GET)
public HttpReturn getStockByID(@PathVariable Integer id){
    //如果id大于100，则抛出自定义的异常
    if(id>100){
        throw new ParamException(400,"Param id is more than 100");
    }
    return new HttpReturn(HttpCodeEnum.OK, stockHM.get(id));
}

正确返回

@RequestMapping( value = "/stocks",method = RequestMethod.GET)
public HttpReturn getStocks(){
    //返回整个HashMap里包含的数据
    return new HttpReturn(HttpCodeEnum.OK, stockHM);
}

4.异常处理

参数异常类exception/ParamException.java

public class ParamException extends RuntimeException {

    //错误码，一般的http返回码对应
    private Integer errorCode;
    //错误信息
    private String errorMsg;

    public ParamException(Integer errorCode,String errorMsg){
        this.errorCode = errorCode;
        this.errorMsg = errorMsg;
    }

    public void setErrorCode(Integer errorCode) {
        this.errorCode = errorCode;
    }

    public void setErrorMsg(String errorMsg) {
        this.errorMsg = errorMsg;
    }

    public Integer getErrorCode() {
        return errorCode;
    }

    public String getErrorMsg() {
        return errorMsg;
    }
}

全局异常处理exception/GlobalExceptionHandler.java

@RestControllerAdvice
public class GlobalExceptionHandler {

    @ExceptionHandler(ParamException.class)
    public HttpReturn handlerParamException(ParamException e) {
        HttpCodeEnum httpCodeEnum;
        httpCodeEnum = HttpCodeEnum.PARAM_ERROR;
        return new HttpReturn(httpCodeEnum,e.getErrorMsg());
    }

    @ExceptionHandler(Exception.class)
    public HttpReturn handlerOtherException(Exception e) {
        HttpCodeEnum httpCodeEnum;
        // 其他异常，当我们定义了多个异常时，这里可以增加判断和记录
        httpCodeEnum = HttpCodeEnum.SERVER_ERROR;
        return new HttpReturn(httpCodeEnum,e.getMessage());
    }
}

使用

@RequestMapping( value = "/stock/{id}",method = RequestMethod.GET)
public HttpReturn getStockByID(@PathVariable Integer id){
    //如果id大于100，则抛出自定义的异常
    if(id>100){
        throw new ParamException(400,"Param id is more than 100");
    }
    return new HttpReturn(HttpCodeEnum.OK, stockHM.get(id));
}