Java實現http請求的幾種常見方式

一、概述

在實際開發過程中，我們經常需要調用對方提供的接口或測試自己寫的接口是否合適。很多項目都會封裝規定好本身項目的接口規範，所以大多數需要去調用對方提供的接口或第三方接口（短信、天氣等）。

在Java項目中調用第三方接口的方式有：

1、通過JDK網絡類Java.net.HttpURLConnection；

2、通過common封裝好的HttpClient；

3、通過Apache封裝好的CloseableHttpClient；

4、通過SpringBoot-RestTemplate；

二、 Java調用第三方http接口的方式

2.1、通過JDK網絡類Java.net.HttpURLConnection

比較原始的一種調用做法，這裏把get請求和post請求都統一放在一個方法裏面。
實現過程：

GET:
1、創建遠程連接
2、設置連接方式（get、post、put。。。）
3、設置連接超時時間
4、設置響應讀取時間
5、發起請求
6、獲取請求數據
7、關閉連接

POST:
1、創建遠程連接
2、設置連接方式（get、post、put。。。）
3、設置連接超時時間
4、設置響應讀取時間
5、當向遠程服務器傳送數據/寫數據時，需要設置爲true（setDoOutput）
6、當前向遠程服務讀取數據時，設置爲true，該參數可有可無（setDoInput）
7、設置傳入參數的格式:（setRequestProperty）
8、設置鑑權信息：Authorization:（setRequestProperty）
9、設置參數
10、發起請求
11、獲取請求數據
12、關閉連接

直接上代碼：

package com.riemann.springbootdemo.util.common.httpConnectionUtil;

import org.springframework.lang.Nullable;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;

/**

@author riemann

@date 2019/05/24 23:42
*/
public class HttpURLConnectionUtil {

/**

Http get請求
@param httpUrl 連接
@return 響應數據
*/
public static String doGet(String httpUrl){
//鏈接
HttpURLConnection connection = null;
InputStream is = null;
BufferedReader br = null;
StringBuffer result = new StringBuffer();
try {
//創建連接
URL url = new URL(httpUrl);
connection = (HttpURLConnection) url.openConnection();
//設置請求方式
connection.setRequestMethod(“GET”);
//設置連接超時時間
connection.setReadTimeout(15000);
//開始連接
connection.connect();
//獲取響應數據
if (connection.getResponseCode() == 200) {
//獲取返回的數據
is = connection.getInputStream();
if (null != is) {
br = new BufferedReader(new InputStreamReader(is, “UTF-8”));
String temp = null;
while (null != (temp = br.readLine())) {
result.append(temp);
}
}
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (null != br) {
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (null != is) {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
//關閉遠程連接
connection.disconnect();
}
return result.toString();
}

/**

Http post請求
@param httpUrl 連接
@param param 參數

@return
/
public static String doPost(String httpUrl, @Nullable String param) {
StringBuffer result = new StringBuffer();
//連接
HttpURLConnection connection = null;
OutputStream os = null;
InputStream is = null;
BufferedReader br = null;
try {
//創建連接對象
URL url = new URL(httpUrl);
//創建連接
connection = (HttpURLConnection) url.openConnection();
//設置請求方法
connection.setRequestMethod(“POST”);
//設置連接超時時間
connection.setConnectTimeout(15000);
//設置讀取超時時間
connection.setReadTimeout(15000);
//DoOutput設置是否向httpUrlConnection輸出，DoInput設置是否從httpUrlConnection讀入，此外發送post請求必須設置這兩個
//設置是否可讀取
connection.setDoOutput(true);
connection.setDoInput(true);
//設置通用的請求屬性
connection.setRequestProperty(“accept”, "/*");
connection.setRequestProperty(“connection”, “Keep-Alive”);
connection.setRequestProperty(“user-agent”, “Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1)”);
connection.setRequestProperty(“Content-Type”, “application/json;charset=utf-8”);

 <span class="token comment">//拼裝參數</span>
 <span class="token keyword">if</span> <span class="token punctuation">(</span>null <span class="token operator">!=</span> param <span class="token operator">&amp;&amp;</span> param<span class="token punctuation">.</span><span class="token function">equals</span><span class="token punctuation">(</span><span class="token string">""</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
     <span class="token operator">/</span><span class="token operator">/</span>設置參數
     os <span class="token operator">=</span> connection<span class="token punctuation">.</span><span class="token function">getOutputStream</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
     <span class="token operator">/</span><span class="token operator">/</span>拼裝參數
     os<span class="token punctuation">.</span><span class="token function">write</span><span class="token punctuation">(</span>param<span class="token punctuation">.</span><span class="token function">getBytes</span><span class="token punctuation">(</span><span class="token string">"UTF-8"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
 <span class="token punctuation">}</span>
 <span class="token operator">/</span><span class="token operator">/</span>設置權限
 <span class="token operator">/</span><span class="token operator">/</span>設置請求頭等
 <span class="token operator">/</span><span class="token operator">/</span>開啓連接
 <span class="token operator">/</span><span class="token operator">/</span>connection<span class="token punctuation">.</span><span class="token function">connect</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
 <span class="token operator">/</span><span class="token operator">/</span>讀取響應
 <span class="token keyword">if</span> <span class="token punctuation">(</span>connection<span class="token punctuation">.</span><span class="token function">getResponseCode</span><span class="token punctuation">(</span><span class="token punctuation">)</span> <span class="token operator">==</span> <span class="token number">200</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
     is <span class="token operator">=</span> connection<span class="token punctuation">.</span><span class="token function">getInputStream</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
     <span class="token keyword">if</span> <span class="token punctuation">(</span>null <span class="token operator">!=</span> is<span class="token punctuation">)</span> <span class="token punctuation">{</span>
         br <span class="token operator">=</span> <span class="token keyword">new</span> <span class="token class-name">BufferedReader</span><span class="token punctuation">(</span><span class="token keyword">new</span> <span class="token class-name">InputStreamReader</span><span class="token punctuation">(</span>is<span class="token punctuation">,</span> <span class="token string">"GBK"</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
         String temp <span class="token operator">=</span> null<span class="token punctuation">;</span>
         <span class="token keyword">while</span> <span class="token punctuation">(</span>null <span class="token operator">!=</span> <span class="token punctuation">(</span>temp <span class="token operator">=</span> br<span class="token punctuation">.</span><span class="token function">readLine</span><span class="token punctuation">(</span><span class="token punctuation">)</span><span class="token punctuation">)</span><span class="token punctuation">)</span> <span class="token punctuation">{</span>
             result<span class="token punctuation">.</span><span class="token function">append</span><span class="token punctuation">(</span>temp<span class="token punctuation">)</span><span class="token punctuation">;</span>
             result<span class="token punctuation">.</span><span class="token function">append</span><span class="token punctuation">(</span><span class="token string">"\r\n"</span><span class="token punctuation">)</span><span class="token punctuation">;</span>
         <span class="token punctuation">}</span>
     <span class="token punctuation">}</span>
 <span class="token punctuation">}</span>

} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} finally {
//關閉連接
if(br!=null){
try {
br.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if(os!=null){
try {
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if(is!=null){
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
//關閉連接
connection.disconnect();
}
return result.toString();
}

public static void main(String[] args) {
String message = doPost(“https://tcc.taobao.com/cc/json/mobile_tel_segment.htm?tel=13026194071”, “”);
System.out.println(message);
}
}

運行結果：

2.2 通過apache common封裝好的HttpClient

httpClient的get或post請求方式步驟：

生成一個HttpClient對象並設置相應的參數；
生成一個GetMethod對象或PostMethod並設置響應的參數；
用HttpClient生成的對象來執行GetMethod生成的Get方法；
處理響應狀態碼；
若響應正常，處理HTTP響應內容；
釋放連接。

導入如下jar包：

<!--HttpClient-->
<dependency>
    <groupId>commons-httpclient</groupId>
    <artifactId>commons-httpclient</artifactId>
    <version>3.1</version>
</dependency>

<!–fastjson–>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.32</version>
</dependency>

代碼如下：

package com.riemann.springbootdemo.util.common.httpConnectionUtil;

import com.alibaba.fastjson.JSONObject;
import org.apache.commons.httpclient.*;
import org.apache.commons.httpclient.methods.GetMethod;
import org.apache.commons.httpclient.methods.PostMethod;
import org.apache.commons.httpclient.params.HttpMethodParams;

import java.io.IOException;

/**

@author riemann
@date 2019/05/25 0:58
/
public class HttpClientUtil {
/*
- httpClient的get請求方式
- 使用GetMethod來訪問一個URL對應的網頁實現步驟：
- 1.生成一個HttpClient對象並設置相應的參數；
- 2.生成一個GetMethod對象並設置響應的參數；
- 3.用HttpClient生成的對象來執行GetMethod生成的Get方法；
- 4.處理響應狀態碼；
- 5.若響應正常，處理HTTP響應內容；
- 6.釋放連接。
- @param url
- @param charset
- @return
 */
 public static String doGet(String url, String charset) {
 //1.生成HttpClient對象並設置參數
 HttpClient httpClient = new HttpClient();
 //設置Http連接超時爲5秒
 httpClient.getHttpConnectionManager().getParams().setConnectionTimeout(5000);
 //2.生成GetMethod對象並設置參數
 GetMethod getMethod = new GetMethod(url);
 //設置get請求超時爲5秒
 getMethod.getParams().setParameter(HttpMethodParams.SO_TIMEOUT, 5000);
 //設置請求重試處理，用的是默認的重試處理：請求三次
 getMethod.getParams().setParameter(HttpMethodParams.RETRY_HANDLER, new DefaultHttpMethodRetryHandler());
 String response = “”;
 //3.執行HTTP GET 請求
 try {
 int statusCode = httpClient.executeMethod(getMethod);
 //4.判斷訪問的狀態碼
 if (statusCode != HttpStatus.SC_OK) {
 System.err.println(“請求出錯：” + getMethod.getStatusLine());
 }
 //5.處理HTTP響應內容
 //HTTP響應頭部信息，這裏簡單打印
 Header[] headers = getMethod.getResponseHeaders();
 for(Header h : headers) {
 System.out.println(h.getName() + “---------------” + h.getValue());
 }
 //讀取HTTP響應內容，這裏簡單打印網頁內容
 //讀取爲字節數組
 byte[] responseBody = getMethod.getResponseBody();
 response = new String(responseBody, charset);
 System.out.println("-----------response:" + response);
 //讀取爲InputStream，在網頁內容數據量大時候推薦使用
 //InputStream response = getMethod.getResponseBodyAsStream();
 } catch (HttpException e) {
 //發生致命的異常，可能是協議不對或者返回的內容有問題
 System.out.println(“請檢查輸入的URL!”);
 e.printStackTrace();
 } catch (IOException e) {
 //發生網絡異常
 System.out.println(“發生網絡異常!”);
 } finally {
 //6.釋放連接
 getMethod.releaseConnection();
 }
 return response;
 }
/**
- post請求
- @param url
- @param json
- @return
 */
 public static String doPost(String url, JSONObject json){
 HttpClient httpClient = new HttpClient();
 PostMethod postMethod = new PostMethod(url);
 
 postMethod.addRequestHeader(“accept”, “/”);
 postMethod.addRequestHeader(“connection”, “Keep-Alive”);
 //設置json格式傳送
 postMethod.addRequestHeader(“Content-Type”, “application/json;charset=GBK”);
 //必須設置下面這個Header
 postMethod.addRequestHeader(“User-Agent”, “Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36”);
 //添加請求參數
 postMethod.addParameter(“commentId”, json.getString(“commentId”));
 
 String res = “”;
 try {
 int code = httpClient.executeMethod(postMethod);
 if (code == 200){
 res = postMethod.getResponseBodyAsString();
 System.out.println(res);
 }
 } catch (IOException e) {
 e.printStackTrace();
 }
 return res;
 }
public static void main(String[] args) {
System.out.println(doGet(“http://tcc.taobao.com/cc/json/mobile_tel_segment.htm?tel=13026194071”, “GBK”));
System.out.println("-----------分割線------------");
System.out.println("-----------分割線------------");
System.out.println("-----------分割線------------");
```
 JSONObject jsonObject = new JSONObject();
 jsonObject.put("commentId", "13026194071");
 System.out.println(doPost("http://tcc.taobao.com/cc/json/mobile_tel_segment.htm?tel=13026194071", jsonObject));
```
}
}

運行結果：

post請求的jsonObject 的參數也成功寫入

2.3 通過Apache封裝好的CloseableHttpClient

CloseableHttpClient是在HttpClient的基礎上修改更新而來的，這裏還涉及到請求頭token的設置（請求驗證），利用fastjson轉換請求或返回結果字符串爲json格式，當然上面兩種方式也是可以設置請求頭token、json的，這裏只在下面說明。

導入如下jar包：

<!--CloseableHttpClient-->
<dependency>
    <groupId>org.apache.httpcomponents</groupId>
    <artifactId>httpclient</artifactId>
    <version>4.5.2</version>
</dependency>

<!–fastjson–>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.32</version>
</dependency>

代碼如下：

package com.riemann.springbootdemo.util.common.httpConnectionUtil;

import com.alibaba.fastjson.JSONObject;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClientBuilder;
import org.apache.http.util.EntityUtils;

import java.io.IOException;
import java.io.UnsupportedEncodingException;

/**

@author riemann
@date 2019/05/25 1:35
*/
public class CloseableHttpClientUtil {

private static String tokenString = “”;
private static String AUTH_TOKEN_EXPIRED = “AUTH_TOKEN_EXPIRED”;
private static CloseableHttpClient httpClient = null;

/**
- 以get方式調用第三方接口
- @param url
- @param token
- @return
 */
 public static String doGet(String url, String token) {
 //創建HttpClient對象
 CloseableHttpClient httpClient = HttpClientBuilder.create().build();
 HttpGet httpGet = new HttpGet(url);
 if (null != tokenString && !tokenString.equals("")) {
 tokenString = getToken();
 }
 //api_gateway_auth_token自定義header頭，用於token驗證使用
 httpGet.addHeader(“api_gateway_auth_token”,tokenString);
 httpGet.addHeader(“User-Agent”, “Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36”);
 try {
 HttpResponse response = httpClient.execute(httpGet);
 if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
 //返回json格式
 String res = EntityUtils.toString(response.getEntity());
 return res;
 }
 } catch (IOException e) {
 e.printStackTrace();
 }
 return null;
 }
/**
- 以post方式調用第三方接口
- @param url
- @param json
- @return
 */
 public static String doPost(String url, JSONObject json) {
 if (null httpClient) {
 httpClient = HttpClientBuilder.create().build();
 }
 HttpPost httpPost = new HttpPost(url);
 if (null != tokenString && tokenString.equals("")) {
 tokenString = getToken();
 }
 //api_gateway_auth_token自定義header頭，用於token驗證使用
 httpPost.addHeader(“api_gateway_auth_token”, tokenString);
 httpPost.addHeader(“User-Agent”, “Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36”);
 try {
 StringEntity se = new StringEntity(json.toString());
 se.setContentEncoding(“UTF-8”);
 //發送json數據需要設置contentType
 se.setContentType(“application/x-www-form-urlencoded”);
 //設置請求參數
 httpPost.setEntity(se);
 HttpResponse response = httpClient.execute(httpPost);
 if (response.getStatusLine().getStatusCode() HttpStatus.SC_OK) {
 //返回json格式
 String res = EntityUtils.toString(response.getEntity());
 return res;
 }
 } catch (IOException e) {
 e.printStackTrace();
 } finally {
 if (httpClient != null){
 try {
 httpClient.close();
 } catch (IOException e) {
 e.printStackTrace();
 }
 }
 }
 return null;
 }
/**
- 獲取第三方接口的token
 */
 public static String getToken() {
 String token = “”;
 JSONObject object = new JSONObject();
 object.put(“appid”, “appid”);
 object.put(“secretkey”, “secretkey”);
 if (null == httpClient) {
 httpClient = HttpClientBuilder.create().build();
 }
 HttpPost httpPost = new HttpPost(“http://localhost/login”);
 httpPost.addHeader(“User-Agent”, “Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.81 Safari/537.36”);
 try {
 StringEntity se = new StringEntity(object.toString());
 se.setContentEncoding(“UTF-8”);
 //發送json數據需要設置contentType
 se.setContentType(“application/x-www-form-urlencoded”);
 //設置請求參數
 httpPost.setEntity(se);
 HttpResponse response = httpClient.execute(httpPost);
 //這裏可以把返回的結果按照自定義的返回數據結果，把string轉換成自定義類
 //ResultTokenBO result = JSONObject.parseObject(response, ResultTokenBO.class);
 //把response轉爲jsonObject
 JSONObject result = (JSONObject) JSONObject.parseObject(String.valueOf(response));
 if (result.containsKey(“token”)) {
 token = result.getString(“token”);
 }
 } catch (IOException e) {
 e.printStackTrace();
 }
 return token;
 }
/**
- 測試
 */
 public static void test(String telephone) {
 
 JSONObject object = new JSONObject();
 object.put(“telephone”, telephone);
 
 //首先獲取token
 tokenString = getToken();
 String response = doPost(“http://localhost/searchUrl”, object);
 //如果返回的結果是list形式的，需要使用JSONObject.parseArray轉換
 //List<Result> list = JSONObject.parseArray(response, Result.class);
 System.out.println(response);
 }
public static void main(String[] args) {
test(“12345678910”);
}
}

2.4 通過SpringBoot-RestTemplate

springBoot-RestTemple是上面三種方式的集大成者，代碼編寫更加簡單，目前可以採用的調用第三方接口有：

delete() 在特定的URL上對資源執行HTTP DELETE操作
exchange() 在URL上執行特定的HTTP方法，返回包含對象的ResponseEntity，這個對象是從響應體中映射得到的
execute() 在URL上執行特定的HTTP方法，返回一個從響應體映射得到的對象
getForEntity() 發送一個HTTP GET請求，返回的ResponseEntity包含了響應體所映射成的對象
getForObject() 發送一個HTTP GET請求，返回的請求體將映射爲一個對象
postForEntity() POST 數據到一個URL，返回包含一個對象的ResponseEntity，這個對象是從響應體中映射得到的
postForObject() POST 數據到一個URL，返回根據響應體匹配形成的對象
headForHeaders() 發送HTTP HEAD請求，返回包含特定資源URL的HTTP頭
optionsForAllow() 發送HTTP OPTIONS請求，返回對特定URL的Allow頭信息
postForLocation() POST 數據到一個URL，返回新創建資源的URL
put() PUT 資源到特定的URL

注意：目前標粗的爲常用的

首先導入springboot的web包

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.4.RELEASE</version>
    </parent>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependencies</span><span class="token punctuation">&gt;</span></span>
    <span class="token comment">&lt;!--CloseableHttpClient--&gt;</span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.apache.httpcomponents<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>httpclient<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>version</span><span class="token punctuation">&gt;</span></span>4.5.2<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>version</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>

    <span class="token comment">&lt;!--spring restTemplate--&gt;</span>
    <span class="token comment">&lt;!-- @ConfigurationProperties annotation processing (metadata for IDEs)
            生成spring-configuration-metadata.json類，需要引入此類--&gt;</span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.springframework.boot<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>spring-boot-configuration-processor<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>optional</span><span class="token punctuation">&gt;</span></span>true<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>optional</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.springframework.boot<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>spring-boot-starter-aop<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.springframework.boot<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>spring-boot-starter-web<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>exclusions</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>exclusion</span><span class="token punctuation">&gt;</span></span>
                <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.springframework.boot<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
                <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>spring-boot-starter-tomcat<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
            <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>exclusion</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>exclusions</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.springframework.boot<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>spring-boot-starter-jetty<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>dependency</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>groupId</span><span class="token punctuation">&gt;</span></span>org.springframework.boot<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>groupId</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>artifactId</span><span class="token punctuation">&gt;</span></span>spring-boot-starter-test<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>artifactId</span><span class="token punctuation">&gt;</span></span>
        <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;</span>scope</span><span class="token punctuation">&gt;</span></span>test<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>scope</span><span class="token punctuation">&gt;</span></span>
    <span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependency</span><span class="token punctuation">&gt;</span></span>
<span class="token tag"><span class="token tag"><span class="token punctuation">&lt;/</span>dependencies</span><span class="token punctuation">&gt;</span></span>

在啓動類同包下創建RestTemplateConfig.java類

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.http.client.ClientHttpRequestFactory;
import org.springframework.http.client.SimpleClientHttpRequestFactory;
import org.springframework.web.client.RestTemplate;

/**

@author riemann
@date 2019/05/25 2:16
*/
@Configuration
public class RestTemplateConfig {

@Bean
public RestTemplate restTemplate(ClientHttpRequestFactory factory){
return new RestTemplate(factory);
}

@Bean
public ClientHttpRequestFactory simpleClientHttpRequestFactory(){
SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
factory.setConnectTimeout(15000);
factory.setReadTimeout(5000);
return factory;
}
}

然後在Service類（RestTemplateToInterface ）中注入使用

具體代碼如下：

import com.alibaba.fastjson.JSONObject;
import com.swordfall.model.User;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.*;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

/**

@author riemann
@date 2019/05/25 2:20
*/
@Service
public class RestTemplateToInterface {

@Autowired
private RestTemplate restTemplate;

/**
- 以get方式請求第三方http接口 getForEntity
- @param url
- @return
 */
 public User doGetWith1(String url){
 ResponseEntity<User> responseEntity = restTemplate.getForEntity(url, User.class);
 User user = responseEntity.getBody();
 return user;
 }
/**
- 以get方式請求第三方http接口 getForObject
- 返回值返回的是響應體，省去了我們再去getBody()
- @param url
- @return
 */
 public User doGetWith2(String url){
 User user = restTemplate.getForObject(url, User.class);
 return user;
 }
/**
- 以post方式請求第三方http接口 postForEntity
- @param url
- @return
 */
 public String doPostWith1(String url){
 User user = new User(“小白”, 20);
 ResponseEntity<String> responseEntity = restTemplate.postForEntity(url, user, String.class);
 String body = responseEntity.getBody();
 return body;
 }
/**
- 以post方式請求第三方http接口 postForEntity
- @param url
- @return
 */
 public String doPostWith2(String url){
 User user = new User(“小白”, 20);
 String body = restTemplate.postForObject(url, user, String.class);
 return body;
 }
/**
- exchange
- @return
 */
 public String doExchange(String url, Integer age, String name){
 //header參數
 HttpHeaders headers = new HttpHeaders();
 String token = “asdfaf2322”;
 headers.add(“authorization”, token);
 headers.setContentType(MediaType.APPLICATION_JSON);
 
 //放入body中的json參數
 JSONObject obj = new JSONObject();
 obj.put(“age”, age);
 obj.put(“name”, name);
 
 //組裝
 HttpEntity<JSONObject> request = new HttpEntity<>(obj, headers);
 ResponseEntity<String> responseEntity = restTemplate.exchange(url, HttpMethod.POST, request, String.class);
 String body = responseEntity.getBody();
 return body;
 }
 }

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