SpringBoot 集成HttpClientUtil 实现http/https请求

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

 

1.简介Https

 

HTTPS协议 = HTTP协议 + SSL/TLS协议，在HTTPS数据传输的过程中，需要用SSL/TLS对数据进行加密和解密，需要用HTTP对加密后的数据进行传输，由此可以看出HTTPS是由HTTP和SSL/TLS一起合作完成的。

一个HTTPS证书的价格还是有点贵，国内有一些云服务器厂商提供免费的HTTPS证书。不过在JDK中提供了一个Java数字证书管理工具keytool,在\jdk\bin目录下，通过这个工具可以自己生成一个数字证书，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 实现http/https请求

试过Spring的RestTemplate，好像Apache的Http Client更合适

2.1 导入jar包

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

2.2 编写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协议GET请求
     public static String httpGet(String url) throws Exception{
         //初始化HttpClient
         CloseableHttpClient httpClient = HttpClients.createDefault();
         //创建HttpGet
         HttpGet httpGet = new HttpGet(url);
         //发起请求，获取response对象
         CloseableHttpResponse response = httpClient.execute(httpGet);
         //获取请求状态码
         //response.getStatusLine().getStatusCode();
         //获取返回数据实体对象
         HttpEntity entity = response.getEntity();
         //转为字符串
         String result = EntityUtils.toString(entity,"UTF-8");
         return result;

     }

     //Http协议Post请求
     public static String httpPost (String url,String json) throws Exception{
         //初始HttpClient
         CloseableHttpClient httpClient = HttpClients.createDefault();
         //创建Post对象
         HttpPost httpPost = new HttpPost(url);
         //设置Content-Type
         httpPost.setHeader("Content-Type","application/json");
         //写入JSON数据
         httpPost.setEntity(new StringEntity(json));
         //发起请求，获取response对象
         CloseableHttpResponse response = httpClient.execute(httpPost);
         //获取请求码
         //response.getStatusLine().getStatusCode();
         //获取返回数据实体对象
         HttpEntity entity = response.getEntity();
         //转为字符串
         String result = EntityUtils.toString(entity,"UTF-8");
         return result;

     }

    //Https协议Get请求
    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协议Post请求
    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{
	//如果下面的方法证书还是不过，报错的话试试下面第二种
		/* 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  编写测试类

    @Test
    public void contextLoads() {

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

这样就可以成功发送HTTPS请求了！

如果想尝试Spring的RestTemplate，可以参考：https://www.cnblogs.com/softidea/p/10663849.html

 

补充

如果报如下错误,只需要在JDK中添加安全证书就好：

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

添加证书命令如下:

• 在命令行切换到证书解压后所在目录  cd /d D:\cert
• 设置JDK的路径　set cacerts="C:\Program Files\java\jdk1.8.0_231\jre\lib\security\cacerts"
• 添加证书　keytool -importcert -keystore %cacerts% -alias nexus -file D:\cert\nexus.cer -storepass changeit -noprompt
• 查看证书列表  keytool -list -v -alias cacert -keystore "C:/Program Files/java/jdk1.8.0_231/jre/lib/security/cacerts" -storepass changeit