customize and configure the most common aspects of HTTP request execution and connection management apache http client - Java Network

Java examples for Network:apache http

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customize and configure the most common aspects of HTTP request execution and connection management apache http client

Demo Code

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package org.apache.http.examples.client;

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.HttpEntity;
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.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;

/**
 * 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).build();

        try {
            HttpGet httpget = new HttpGet("http://www.apache.org/");
            // 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 {
                HttpEntity entity = response.getEntity();

                System.out
                        .println("----------------------------------------");
                System.out.println(response.getStatusLine());
                if (entity != null) {
                    System.out.println("Response content length: "
                            + entity.getContentLength());
                }
                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();
        }
    }

}

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