SpringBoot 集成HttpClientUtil 實現http/https請求

原文地址：https://blog.csdn.net/qq_27661035/article/details/88654727

 

1.簡介Https

 

HTTPS協議 = HTTP協議 + SSL/TLS協議，在HTTPS數據傳輸的過程中，需要用SSL/TLS對數據進行加密和解密，需要用HTTP對加密后的數據進行傳輸，由此可以看出HTTPS是由HTTP和SSL/TLS一起合作完成的。

一個HTTPS證書的價格還是有點貴，國內有一些雲服務器廠商提供免費的HTTPS證書。不過在JDK中提供了一個Java數字證書管理工具keytool,在\jdk\bin目錄下，通過這個工具可以自己生成一個數字證書，命令如下

keytool -genkey  -alias tomcathttps -keyalg RSA -keysize 2048 -keystore sang.p12 -validity 365

　　

2. 在Spring boot中利用HttpClientUtil 實現http/https請求

試過Spring的RestTemplate，好像Apache的Http Client更合適

2.1 導入jar包

<dependency>
            <groupId>org.apache.httpcomponents</groupId>
            <artifactId>httpclient</artifactId>
            <version>4.5.7</version>
</dependency>

2.2 編寫HttpClientUtil 

import org.apache.http.HttpEntity;
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.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.ssl.SSLContextBuilder;
import org.apache.http.ssl.TrustStrategy;
import org.apache.http.util.EntityUtils;
import javax.net.ssl.SSLContext;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;

public class HttpUtils {
     //Http協議GET請求
     public static String httpGet(String url) throws Exception{
         //初始化HttpClient
         CloseableHttpClient httpClient = HttpClients.createDefault();
         //創建HttpGet
         HttpGet httpGet = new HttpGet(url);
         //發起請求，獲取response對象
         CloseableHttpResponse response = httpClient.execute(httpGet);
         //獲取請求狀態碼
         //response.getStatusLine().getStatusCode();
         //獲取返回數據實體對象
         HttpEntity entity = response.getEntity();
         //轉為字符串
         String result = EntityUtils.toString(entity,"UTF-8");
         return result;

     }

     //Http協議Post請求
     public static String httpPost (String url,String json) throws Exception{
         //初始HttpClient
         CloseableHttpClient httpClient = HttpClients.createDefault();
         //創建Post對象
         HttpPost httpPost = new HttpPost(url);
         //設置Content-Type
         httpPost.setHeader("Content-Type","application/json");
         //寫入JSON數據
         httpPost.setEntity(new StringEntity(json));
         //發起請求，獲取response對象
         CloseableHttpResponse response = httpClient.execute(httpPost);
         //獲取請求碼
         //response.getStatusLine().getStatusCode();
         //獲取返回數據實體對象
         HttpEntity entity = response.getEntity();
         //轉為字符串
         String result = EntityUtils.toString(entity,"UTF-8");
         return result;

     }

    //Https協議Get請求
    public static String httpsGet(String url) throws Exception{
        CloseableHttpClient hp = createSSLClientDefault();
        HttpGet hg = new HttpGet(url);
        CloseableHttpResponse response = hp.execute(hg);
        HttpEntity entity = response.getEntity();
        String content = EntityUtils.toString(entity,"UTF-8");
        hp.close();
        return content;
    }
    //Https協議Post請求
    public static String httpsPost(String url, String json) throws Exception{

         CloseableHttpClient hp = createSSLClientDefault();
         HttpPost httpPost = new HttpPost(url);
         httpPost.setHeader("Content-Type","application/json");
         httpPost.setEntity(new StringEntity(json));
         CloseableHttpResponse response = hp.execute(httpPost);
         HttpEntity entity = response.getEntity();
         String content = EntityUtils.toString(entity,"UTF-8");
         hp.close();
         return content;
    }

	
	public static CloseableHttpClient createSSLClientDefault() throws Exception{
	//如果下面的方法證書還是不過，報錯的話試試下面第二種
		/* SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy(){
		//信任所有
		public boolean isTrusted(X509Certificate[] chain, String authType) throws CertificateException {
		return true;
		}
		}).build();
		SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext);
		return HttpClients.custom().setSSLSocketFactory(sslsf).build();*/

	    SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(
               SSLContexts.custom().loadTrustMaterial(null, new TrustSelfSignedStrategy()).build(), 
                  NoopHostnameVerifier.INSTANCE);
        return HttpClients.custom().setSSLSocketFactory(sslsf).build();

}


}

　　

 

2.3  編寫測試類

    @Test
    public void contextLoads() {

        try {
            String result = HttpUtils.httpGet("https://XXX");
            System.out.println("返回值>>>："+result);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

這樣就可以成功發送HTTPS請求了！

如果想嘗試Spring的RestTemplate，可以參考：https://www.cnblogs.com/softidea/p/10663849.html

 

補充

如果報如下錯誤,只需要在JDK中添加安全證書就好：

sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

添加證書命令如下:

• 在命令行切換到證書解壓后所在目錄  cd /d D:\cert
• 設置JDK的路徑　set cacerts="C:\Program Files\java\jdk1.8.0_231\jre\lib\security\cacerts"
• 添加證書　keytool -importcert -keystore %cacerts% -alias nexus -file D:\cert\nexus.cer -storepass changeit -noprompt
• 查看證書列表  keytool -list -v -alias cacert -keystore "C:/Program Files/java/jdk1.8.0_231/jre/lib/security/cacerts" -storepass changeit