SpringBoot 如何使用RestTemplate發(fā)送Post請求

更新時間：2021年08月19日 11:53:30 作者：占位符號

這篇文章主要介紹了SpringBoot 如何使用RestTemplate發(fā)送Post請求的操作，具有很好的參考價值，希望對大家有所幫助。如有錯誤或未考慮完全的地方，望不吝賜教

背景：

用戶信息放在8081端口的應用上，8082端口應用通過調(diào)用api，傳遞參數(shù)，從8081端口應用的數(shù)據(jù)庫中獲取用戶的信息。

1、待訪問的API

我要訪問的api是 localhost:8081/authority/authorize，這個api需要傳遞三個參數(shù)，分別是domain(域名)，account（用戶賬號），key（用戶秘鑰）。先用postman測試一下，返回結果如下：

分別展示了驗證成功和驗證失敗的例子。

2、返回對象

ResultVO類是我構造的類，將會格式化api返回的數(shù)據(jù)，實現(xiàn)如下：

ResultVO.java

package com.seven.site.VO;
/**
 * @author: Seven.wk
 * @description: 數(shù)據(jù)返回類
 * @create: 2018/07/04
 */
public class ResultVO<T> {
    private Integer code;
    private String message;
    private T data;
    public ResultVO() {
    }
    public ResultVO(Integer code, String message) {
        this.code = code;
        this.message = message;
    }
    public ResultVO(Integer code, String message, T data) {
        this.code = code;
        this.message = message;
        this.data = data;
    }
    public Integer getCode() {
        return code;
    }
    public void setCode(Integer code) {
        this.code = code;
    }
    public String getMessage() {
        return message;
    }
    public void setMessage(String message) {
        this.message = message;
    }
    public T getData() {
        return data;
    }
    public void setData(T data) {
        this.data = data;
    }    
}

3、將發(fā)送Post請求的部分封裝如下

Utils.java

package com.seven.site.utils;
import com.seven.site.VO.ResultVO;
import org.springframework.http.*;
import org.springframework.util.MultiValueMap;
import org.springframework.web.client.RestTemplate;
/**
 * @author: Seven.wk
 * @description: 輔助工具類
 * @create: 2018/07/04
 */
public class Utils {
    /**
     * 向目的URL發(fā)送post請求
     * @param url       目的url
     * @param params    發(fā)送的參數(shù)
     * @return  ResultVO
     */
    public static ResultVO sendPostRequest(String url, MultiValueMap<String, String> params){
        RestTemplate client = new RestTemplate();
        HttpHeaders headers = new HttpHeaders();
        HttpMethod method = HttpMethod.POST;
        // 以表單的方式提交
        headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
        //將請求頭部和參數(shù)合成一個請求
        HttpEntity<MultiValueMap<String, String>> requestEntity = new HttpEntity<>(params, headers);
        //執(zhí)行HTTP請求，將返回的結構使用ResultVO類格式化
        ResponseEntity<ResultVO> response = client.exchange(url, method, requestEntity, ResultVO.class);
        return response.getBody();
    }
}

4、UserInfo對象

UserInfo.java

package com.seven.site.entity;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import java.util.Date;
/**
 * @author: Seven.wk
 * @description: 用戶信息實體
 * @create: 2018/07/04
 */
@Entity
public class UserInfo {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer userId;         //用戶標識id
    private String userName;        //用戶姓名
    private String userAccount;         //用戶賬號
    private String userPassword;        //用戶密碼
    private Date createTime = new Date(System.currentTimeMillis());     //創(chuàng)建時間
    public UserInfo() {
    }
    public UserInfo(Object userAccount, Object userName) {
    }
    public UserInfo(String userAccount, String userName) {
        this.userName = userName;
        this.userAccount = userAccount;
    }
    public UserInfo(String userAccount, String userName, String userPassword) {
        this.userName = userName;
        this.userAccount = userAccount;
        this.userPassword = userPassword;
    }
    public Integer getUserId() {
        return userId;
    }
    public void setUserId(Integer userId) {
        this.userId = userId;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public String getUserAccount() {
        return userAccount;
    }
    public void setUserAccount(String userAccount) {
        this.userAccount = userAccount;
    }
    public String getUserPassword() {
        return userPassword;
    }
    public void setUserPassword(String userPassword) {
        this.userPassword = userPassword;
    }
    public Date getCreateTime() {
        return createTime;
    }
    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }
    @Override
    public String toString() {
        return "UserInfo{" +
                "userId=" + userId +
                ", userName='" + userName + '\'' +
                ", userAccount='" + userAccount + '\'' +
                ", userPassword='" + userPassword + '\'' +
                ", createTime=" + createTime +
                '}';
    }
}

5、在Service層封裝將要發(fā)送的參數(shù)

并調(diào)用該方法，將返回的結果格式化成UserInfo對象，其中的異常處理部分就不詳述了。

注:其中的URL地址一定要加上協(xié)議前綴（http，https等）

UserInfoServiceImpl.java

public UserInfo getUserInfoFromAuthority(String domain, String account, String key) {
    String authorizeUrl = "http://localhost:8081/authority/authorize";
    MultiValueMap<String, String> params = new LinkedMultiValueMap<>();
    params.add("domain", domain);
    params.add("account", account);
    params.add("key", key);
    //發(fā)送Post數(shù)據(jù)并返回數(shù)據(jù)
    ResultVO resultVo = Utils.sendPostRequest(authorizeUrl, params);
    if(resultVo.getCode() != 20){       //進行異常處理
        switch (resultVo.getCode()){
            case 17: throw new SiteException(ResultEnum.AUTHORIZE_DOMAIN_NOT_EXIST);
            case 18: throw new SiteException(ResultEnum.AUTHORIZE_USER_NOT_EXIST);
            case 19: throw new SiteException(ResultEnum.AUTHORIZE_USER_INFO_INCORRECT);
            default: throw new SiteException(ResultEnum.SYSTEM_ERROR);
        }
    }
    LinkedHashMap infoMap = (LinkedHashMap) resultVo.getData();
    return new UserInfo((String) infoMap.get("userAccount"), (String) infoMap.get("userName"), key);
}

6、在控制器中調(diào)用service中的方法，并返回數(shù)據(jù)

IndexController.java

/**
 * 獲取用戶信息
 * @param domain        域名
 * @param account       用戶輸入的賬號
 * @param password      用戶輸入的密碼
 * @return ResultVO
 */
@PostMapping("/getInfo")
@ResponseBody
public ResultVO getInfo(@RequestParam("domain") String domain,
                        @RequestParam("account") String account,
                        @RequestParam("password") String password) {
    UserInfo userInfo;
    try{
        userInfo = userInfoService.getUserInfoFromAuthority(domain, account, password);
    }catch(SiteException e){
        return new ResultVO(e.getCode(), e.getMessage());
    }
    return new ResultVO<>(20, "登錄成功", userInfo);
}