以下实例基于HttpClient 4.3：
package com.alimama.utils;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.nio.charset.CodingErrorAction;
import java.util.Arrays;
import javax.net.ssl.SSLContext;
import org.apache.http.Consts;
import org.apache.http.Header;
import org.apache.http.HttpHost;
import org.apache.http.HttpRequest;
import org.apache.http.HttpResponse;
import org.apache.http.ParseException;
import org.apache.http.client.CookieStore;
import org.apache.http.client.CredentialsProvider;
import org.apache.http.client.config.AuthSchemes;
import org.apache.http.client.config.CookieSpecs;
import org.apache.http.client.config.RequestConfig;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.protocol.HttpClientContext;
import org.apache.http.config.ConnectionConfig;
import org.apache.http.config.MessageConstraints;
import org.apache.http.config.Registry;
import org.apache.http.config.RegistryBuilder;
import org.apache.http.config.SocketConfig;
import org.apache.http.conn.DnsResolver;
import org.apache.http.conn.HttpConnectionFactory;
import org.apache.http.conn.ManagedHttpClientConnection;
import org.apache.http.conn.routing.HttpRoute;
import org.apache.http.conn.socket.ConnectionSocketFactory;
import org.apache.http.conn.socket.PlainConnectionSocketFactory;
import org.apache.http.conn.ssl.SSLConnectionSocketFactory;
import org.apache.http.impl.DefaultHttpResponseFactory;
import org.apache.http.impl.client.BasicCookieStore;
import org.apache.http.impl.client.BasicCredentialsProvider;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.DefaultHttpRequestRetryHandler;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.impl.conn.DefaultHttpResponseParser;
import org.apache.http.impl.conn.DefaultHttpResponseParserFactory;
import org.apache.http.impl.conn.ManagedHttpClientConnectionFactory;
import org.apache.http.impl.conn.PoolingHttpClientConnectionManager;
import org.apache.http.impl.conn.SystemDefaultDnsResolver;
import org.apache.http.impl.io.DefaultHttpRequestWriterFactory;
import org.apache.http.io.HttpMessageParser;
import org.apache.http.io.HttpMessageParserFactory;
import org.apache.http.io.HttpMessageWriterFactory;
import org.apache.http.io.SessionInputBuffer;
import org.apache.http.message.BasicHeader;
import org.apache.http.message.BasicLineParser;
import org.apache.http.message.LineParser;
import org.apache.http.ssl.SSLContexts;
import org.apache.http.util.CharArrayBuffer;
import org.apache.http.util.EntityUtils;
/**
* This example demonstrates how to customize and configure the most common aspects
* of HTTP request execution and connection management.
*/
public class ClientConfiguration {
public final static void main(String[] args) throws Exception {
// Use custom message parser / writer to customize the way HTTP
// messages are parsed from and written out to the data stream.
HttpMessageParserFactory<HttpResponse> responseParserFactory = new DefaultHttpResponseParserFactory() {
@Override
public HttpMessageParser<HttpResponse> create(
SessionInputBuffer buffer, MessageConstraints constraints) {
LineParser lineParser = new BasicLineParser() {
@Override
public Header parseHeader(final CharArrayBuffer buffer) {
try {
return super.parseHeader(buffer);
} catch (ParseException ex) {
return new BasicHeader(buffer.toString(), null);
}
}
};
return new DefaultHttpResponseParser(
buffer, lineParser, DefaultHttpResponseFactory.INSTANCE, constraints) {
@Override
protected boolean reject(final CharArrayBuffer line, int count) {
// try to ignore all garbage preceding a status line infinitely
return false;
}
};
}
};
HttpMessageWriterFactory<HttpRequest> requestWriterFactory = new DefaultHttpRequestWriterFactory();
// Use a custom connection factory to customize the process of
// initialization of outgoing HTTP connections. Beside standard connection
// configuration parameters HTTP connection factory can define message
// parser / writer routines to be employed by individual connections.
HttpConnectionFactory<HttpRoute, ManagedHttpClientConnection> connFactory = new ManagedHttpClientConnectionFactory(
requestWriterFactory, responseParserFactory);
// Client HTTP connection objects when fully initialized can be bound to
// an arbitrary network socket. The process of network socket initialization,
// its connection to a remote address and binding to a local one is controlled
// by a connection socket factory.
// SSL context for secure connections can be created either based on
// system or application specific properties.
SSLContext sslcontext = SSLContexts.createSystemDefault();
// Create a registry of custom connection socket factories for supported
// protocol schemes.
Registry<ConnectionSocketFactory> socketFactoryRegistry = RegistryBuilder.<ConnectionSocketFactory>create()
.register("http", PlainConnectionSocketFactory.INSTANCE)
.register("https", new SSLConnectionSocketFactory(sslcontext))
.build();
// Use custom DNS resolver to override the system DNS resolution.
DnsResolver dnsResolver = new SystemDefaultDnsResolver() {
@Override
public InetAddress[] resolve(final String host) throws UnknownHostException {
if (host.equalsIgnoreCase("myhost")) {
return new InetAddress[] { InetAddress.getByAddress(new byte[] {127, 0, 0, 1}) };
} else {
return super.resolve(host);
}
}
};
// Create a connection manager with custom configuration.
PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager(
socketFactoryRegistry, connFactory, dnsResolver);
// Create socket configuration
SocketConfig socketConfig = SocketConfig.custom()
.setTcpNoDelay(true)
.build();
// Configure the connection manager to use socket configuration either
// by default or for a specific host.
connManager.setDefaultSocketConfig(socketConfig);
connManager.setSocketConfig(new HttpHost("somehost", 80), socketConfig);
// Validate connections after 1 sec of inactivity
connManager.setValidateAfterInactivity(1000);
// Create message constraints
MessageConstraints messageConstraints = MessageConstraints.custom()
.setMaxHeaderCount(200)
.setMaxLineLength(2000)
.build();
// Create connection configuration
ConnectionConfig connectionConfig = ConnectionConfig.custom()
.setMalformedInputAction(CodingErrorAction.IGNORE)
.setUnmappableInputAction(CodingErrorAction.IGNORE)
.setCharset(Consts.UTF_8)
.setMessageConstraints(messageConstraints)
.build();
// Configure the connection manager to use connection configuration either
// by default or for a specific host.
connManager.setDefaultConnectionConfig(connectionConfig);
connManager.setConnectionConfig(new HttpHost("somehost", 80), ConnectionConfig.DEFAULT);
// Configure total max or per route limits for persistent connections
// that can be kept in the pool or leased by the connection manager.
connManager.setMaxTotal(100);
connManager.setDefaultMaxPerRoute(10);
connManager.setMaxPerRoute(new HttpRoute(new HttpHost("somehost", 80)), 20);
// Use custom cookie store if necessary.
CookieStore cookieStore = new BasicCookieStore();
// Use custom credentials provider if necessary.
CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
// Create global request configuration
RequestConfig defaultRequestConfig = RequestConfig.custom()
.setCookieSpec(CookieSpecs.DEFAULT)
.setExpectContinueEnabled(true)
.setTargetPreferredAuthSchemes(Arrays.asList(AuthSchemes.NTLM, AuthSchemes.DIGEST))
.setProxyPreferredAuthSchemes(Arrays.asList(AuthSchemes.BASIC))
.build();
// Create an HttpClient with the given custom dependencies and configuration.
CloseableHttpClient httpclient = HttpClients.custom()
.setConnectionManager(connManager)
.setDefaultCookieStore(cookieStore)
.setDefaultCredentialsProvider(credentialsProvider)
.setProxy(new HttpHost("myproxy", 8080))
.setDefaultRequestConfig(defaultRequestConfig)
.setRetryHandler(new DefaultHttpRequestRetryHandler(0,false))
.build();
try {
HttpGet httpget = new HttpGet("http://httpbin.org/get");
// Request configuration can be overridden at the request level.
// They will take precedence over the one set at the client level.
RequestConfig requestConfig = RequestConfig.copy(defaultRequestConfig)
.setSocketTimeout(5000)
.setConnectTimeout(5000)
.setConnectionRequestTimeout(5000)
.setProxy(new HttpHost("myotherproxy", 8080))
.build();
httpget.setConfig(requestConfig);
// Execution context can be customized locally.
HttpClientContext context = HttpClientContext.create();
// Contextual attributes set the local context level will take
// precedence over those set at the client level.
context.setCookieStore(cookieStore);
context.setCredentialsProvider(credentialsProvider);
System.out.println("executing request " + httpget.getURI());
CloseableHttpResponse response = httpclient.execute(httpget, context);
try {
System.out.println("----------------------------------------");
System.out.println(response.getStatusLine());
System.out.println(EntityUtils.toString(response.getEntity()));
System.out.println("----------------------------------------");
// Once the request has been executed the local context can
// be used to examine updated state and various objects affected
// by the request execution.
// Last executed request
context.getRequest();
// Execution route
context.getHttpRoute();
// Target auth state
context.getTargetAuthState();
// Proxy auth state
context.getTargetAuthState();
// Cookie origin
context.getCookieOrigin();
// Cookie spec used
context.getCookieSpec();
// User security token
context.getUserToken();
} finally {
response.close();
}
} finally {
httpclient.close();
}
}
}
