详解sslconnectionsocketfactory

一、什么是sslconnectionsocketfactory

sslconnectionsocketfactory是Java中处理与HTTPS连接有关的类。在Java中，这个类是用于启用SSL（安全套接层）或TLS（传输层安全协议）加密的，从而为数据传输提供更高的安全性。

使用sslconnectionsocketfactory，可以使Java应用程序得以对HTTPS请求进行安全的网络通信。

二、sslconnectionsocketfactory的使用方法

打开Java的官方文档，我们可以看到使用sslconnectionsocketfactory的流程如下：

// 创建sslcontext对象
SSLContext sslContext = SSLContext.getInstance("SSL");

// 设置信任管理器
TrustManager[] trustManagers = {new X509TrustManager() {...}};
sslContext.init(null, trustManagers, null);

// 创建sslconnectionsocketfactory对象，并将sslContext作为参数传入
SSLSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext);

// 创建HttpClient对象，并将sslsf作为参数传入
CloseableHttpClient httpClient = HttpClients.custom().setSSLSocketFactory(sslsf).build();

通过上述代码，我们使用sslconnectionsocketfactory建立了一个HTTPS连接，其中：

• 创建sslcontext对象：SSL协议上下文
• 设置信任管理器：定义信任的策略
• 创建sslconnectionsocketfactory对象：负责传输安全数据的实例
• 创建HttpClient对象：访问HTTPS网站的对象

三、sslconnectionsocketfactory的主要方法

sslconnectionsocketfactory类提供了以下重要的方法：

1. createSocket()

创建套接字连接。

public Socket createSocket(final HttpContext context) throws IOException { ... }

2. connectSocket()

与服务器建立SSL/TLS连接。

public Socket connectSocket(
    final int connectTimeout,
    final Socket socket,
    final HttpHost host,
    final InetSocketAddress remoteAddress,
    final InetSocketAddress localAddress,
    final HttpContext context) throws IOException { ... }

3. getSocketFactory()

获取套接字工厂。

public static SSLConnectionSocketFactory getSocketFactory() {...}

四、示例代码

示例1：创建HttpClient对象并访问HTTPS网站

import javax.net.ssl.SSLContext;
import javax.net.ssl.X509TrustManager;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpUriRequest;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.conn.ssl.TrustStrategy;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class HttpClientUtil {

    /**
     * 发送Https请求
     *
     * @param url 请求地址
     * @return 返回响应结果
     */
    public static String sendHttpsRequest(String url) {
        String respContent = null;
        CloseableHttpClient httpClient = null;
        CloseableHttpResponse httpResponse = null;
        try {
            // Create a trust manager that does not validate certificate chains
            TrustStrategy trustStrategy = (chain, authType) -> true;
            SSLContext sslContext = SSLContext.getInstance("TLS");
            sslContext.init(null, new X509TrustManager[]{new X509TrustManager() {
                @Override
                public void checkClientTrusted(java.security.cert.X509Certificate[] chain, String authType) {}

                @Override
                public void checkServerTrusted(java.security.cert.X509Certificate[] chain, String authType) {}

                @Override
                public java.security.cert.X509Certificate[] getAcceptedIssuers() {
                    return null;
                }
            }}, null);
            SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext);
            httpClient = HttpClients.custom().setSSLSocketFactory(sslsf).build();
            HttpUriRequest request = new HttpGet(url);

            httpResponse = httpClient.execute(request);
            HttpEntity entity = httpResponse.getEntity();
            respContent = EntityUtils.toString(entity, "UTF-8");
            System.out.println(respContent);
        } catch (Exception e) {
            System.out.println(e.getMessage());
        } finally {
            try {
                httpResponse.close();
                httpClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return respContent;
    }
}

示例2：信任任何HTTPS证书

    public static CloseableHttpClient createIgnoreSslHttpClient() throws Exception {
        SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, TrustAllStrategy.INSTANCE).build();
        SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext, (hostname, session) -> true);
        return HttpClients.custom().setSSLSocketFactory(sslsf).build();
    }
    
    private static enum TrustAllStrategy implements TrustStrategy {
        INSTANCE;

        @Override
        public boolean isTrusted(X509Certificate[] chain, String authType) {
            return true;
        }
    }