自定义HttpClient
使用HttpClients.createDefault()这个默认配置的方法有时候并不能满足需求，无法配置证书和协议，下面代码演示怎样自定义HttpClient.
package com.jiangtengfei.https;
import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
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.io.IOException;
import java.security.KeyManagementException;
import java.security.KeyStoreException;
import java.security.NoSuchAlgorithmException;
import java.security.cert.CertificateException;
import java.security.cert.X509Certificate;
/**
* Created by jiangtengfei on 16/3/2.
*/
public class HttpClientHttpsTest {
public static void httpsTest() {
CloseableHttpClient httpClient = null;
try {
SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, new TrustStrategy() {
public boolean isTrusted(X509Certificate[] x509Certificates, String s) throws CertificateException {
return true;
}
}).build();
SSLConnectionSocketFactory sslsf = new SSLConnectionSocketFactory(sslContext);
httpClient = HttpClients.custom().setSSLSocketFactory(sslsf).build();
if (httpClient != null) {
HttpGet httpGet = new HttpGet("https://www.baidu.com");
CloseableHttpResponse response = httpClient.execute(httpGet);
try {
HttpEntity entity = response.getEntity();
System.out.println("--------------------------------------");
if (entity != null) {
System.out.println("Response content length: " + entity.getContentLength());
System.out.println(EntityUtils.toString(entity));
EntityUtils.consume(entity);
}
} finally {
response.close();
}
}
} catch (KeyManagementException e) {
e.printStackTrace();
} catch (KeyStoreException e) {
e.printStackTrace();
} catch (NoSuchAlgorithmException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
HttpClientHttpsTest.httpsTest();
}
}
有些情况下可能会报这样的错：
javax.net.ssl.SSLProtocolException: handshake alert: unrecognized_name
这是可以试试在方法里加上：
System.setProperty ("jsse.enableSNIExtension", "false");
如果需要使用HttpClient获取cookie信息，则在构建HttpClient实例的时候需要加上相关配置：
CookieStore cookieStore = new BasicCookieStor();
httpClient = HttpClients.custom().setSSLSocketFactory(salsa).setDefaultCookieStore(cookieStore).build();
等执行了httpClient.execute(httpGet);后，就可以获取到cookie了：
List cookies = cookieStore.getCookies();
禁止HttpClient follow redirect
要禁止HttpClient重定向，可以传入自定义的DefaultRedirectStrategy重定向策略
HttpClient httpClient = HttpClientBuilder.create().setRedirectStrategy(new DefaultRedirectStrategy() {
@Override
protected boolean isRedirectable(String method) {
return false
}
}).build()
仅作演示用，不要在意代码风格这些细节