Java tutorial
package org.jolokia.client; /* * Copyright 2009-2013 Roland Huss * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.net.URI; import java.net.URISyntaxException; import java.nio.charset.Charset; import java.util.Map; import javax.net.ssl.SSLContext; import org.apache.http.HttpHost; import org.apache.http.auth.AuthScope; import org.apache.http.auth.UsernamePasswordCredentials; import org.apache.http.client.CookieStore; import org.apache.http.client.CredentialsProvider; import org.apache.http.client.HttpClient; import org.apache.http.client.config.RequestConfig; import org.apache.http.config.*; import org.apache.http.conn.*; 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.*; import org.apache.http.impl.client.*; import org.apache.http.impl.conn.*; import org.apache.http.impl.io.DefaultHttpRequestWriterFactory; import org.apache.http.impl.io.DefaultHttpResponseParserFactory; import org.apache.http.protocol.HTTP; import org.apache.http.util.VersionInfo; import org.jolokia.client.request.*; /** * A builder for a {@link org.jolokia.client.J4pClient}. * * @author roland * @since 26.11.10 */ public class J4pClientBuilder { private int connectionTimeout; private int socketTimeout; private int maxTotalConnections; private int maxConnectionPoolTimeout; private Charset contentCharset; private boolean expectContinue; private boolean tcpNoDelay; private int socketBufferSize; // whether to use thread safe, pooled connections private boolean pooledConnections; // Connection URL to use private String url; // User to use for authentication private String user; // Password to use for authentication private String password; // Service-URL when used in proxy mode private String targetUrl; // User used for JSR-160 communication when using with a proxy (i.e. targetUrl != null) private String targetUser; // Password to use for JSR-160 communication when using with a proxy (i.e. targetUrl != null and targetUser != null) private String targetPassword; // Cookie store to use, might contain already prepared cookies used for a login private CookieStore cookieStore; // Authenticator to use for performing a login private J4pAuthenticator authenticator; // HTTP proxy settings private Proxy httpProxy; // Extractor used creating responses private J4pResponseExtractor responseExtractor; /** * Package access constructor, use static method on J4pClient for creating * the builder. */ public J4pClientBuilder() { connectionTimeout(20 * 1000); socketTimeout(-1); maxTotalConnections(20); maxConnectionPoolTimeout(500); contentCharset(HTTP.DEF_CONTENT_CHARSET.name()); expectContinue(true); tcpNoDelay(true); socketBufferSize(8192); pooledConnections(); user(null); password(null); cookieStore(new BasicCookieStore()); authenticator(new BasicAuthenticator()); responseExtractor(ValidatingResponseExtractor.DEFAULT); } /** * The Agent URL to connect to * * @param pUrl agent URL */ public final J4pClientBuilder url(String pUrl) { url = pUrl; return this; } /** * User to use for authentication * * @param pUser user name */ public final J4pClientBuilder user(String pUser) { user = pUser; return this; } /** * Password for authentication * * @param pPassword password to use */ public final J4pClientBuilder password(String pPassword) { password = pPassword; return this; } /** * Target service URL when using the agent as a JSR-160 proxy * * @param pUrl JMX service URL for the 'real' target (that gets contacted by the agent) */ public final J4pClientBuilder target(String pUrl) { targetUrl = pUrl; return this; } /** * Target user for proxy mode. This parameter takes only effect when a target is set. * * @param pUser User to be used for authentication in JSR-160 proxy communication */ public final J4pClientBuilder targetUser(String pUser) { targetUser = pUser; return this; } /** * Target password for proxy mode. This parameter takes only effect when a target is set and the target user is * not null * * @param pPassword Password to be used for authentication in JSR-160 proxy communication */ public final J4pClientBuilder targetPassword(String pPassword) { targetPassword = pPassword; return this; } /** * Use a single threaded client for connecting to the agent. This * is not very suitable in multithreaded environments */ public final J4pClientBuilder singleConnection() { pooledConnections = false; return this; } /** * Use a pooled connection manager for connecting to the agent, which * uses a pool of connections (see {@link #maxTotalConnections(int) and {@link #maxConnectionPoolTimeout(int)} for * tuning the pool} */ public final J4pClientBuilder pooledConnections() { pooledConnections = true; return this; } /** * Determines the timeout in milliseconds until a connection is established. A timeout value of zero is * interpreted as an infinite timeout. Default is 20 seconds. * * @param pTimeOut timeout in milliseconds */ public final J4pClientBuilder connectionTimeout(int pTimeOut) { connectionTimeout = pTimeOut; return this; } /** * Defines the socket timeout (<code>SO_TIMEOUT</code>) in milliseconds, * which is the timeout for waiting for data or, put differently, * a maximum period inactivity between two consecutive data packets). * A timeout value of zero is interpreted as an infinite timeout, a negative value means the system default. * * @param pTimeOut SO_TIMEOUT value in milliseconds, 0 mean no timeout at all. */ public final J4pClientBuilder socketTimeout(int pTimeOut) { socketTimeout = pTimeOut; return this; } /** * Sets the maximum number of connections allowed when using {@link #pooledConnections()}. * @param pConnections number of max. simultaneous connections. */ public final J4pClientBuilder maxTotalConnections(int pConnections) { maxTotalConnections = pConnections; return this; } /** * Sets the timeout in milliseconds used when retrieving a connection * from the connection manager. Default is 500ms, if set to -1 the system default is used. Use * 0 for an infinite timeout. * * @param pConnectionPoolTimeout timeout in milliseconds */ public final J4pClientBuilder maxConnectionPoolTimeout(int pConnectionPoolTimeout) { maxConnectionPoolTimeout = pConnectionPoolTimeout; return this; } /** * Defines the charset to be used per default for encoding content body. * @param pContentCharset the charset to use */ public final J4pClientBuilder contentCharset(String pContentCharset) { return contentCharset(Charset.forName(pContentCharset)); } /** * Defines the charset to be used per default for encoding content body. * @param pContentCharset the charset to use */ public final J4pClientBuilder contentCharset(Charset pContentCharset) { contentCharset = pContentCharset; return this; } /** * Activates 'Expect: 100-Continue' handshake for the entity enclosing methods. * The purpose of the 'Expect: 100-Continue' handshake to allow a client that is * sending a request message with a request body to determine if the origin server * is willing to accept the request (based on the request headers) before the client * sends the request body. * The use of the 'Expect: 100-continue' handshake can result in noticable peformance * improvement for entity enclosing requests that require the target server's authentication. * * @param pUse whether to use this algorithm or not */ public final J4pClientBuilder expectContinue(boolean pUse) { expectContinue = pUse; return this; } /** * Determines whether Nagle's algorithm is to be used. The Nagle's algorithm tries to conserve * bandwidth by minimizing the number of segments that are sent. When applications wish to * decrease network latency and increase performance, they can disable Nagle's * algorithm (that is enable TCP_NODELAY). Data will be sent earlier, at the cost * of an increase in bandwidth consumption. * @param pUse whether to use NO_DELAY or not */ public final J4pClientBuilder tcpNoDelay(boolean pUse) { tcpNoDelay = pUse; return this; } /** * Determines the size of the internal socket buffer used to buffer data while receiving / * transmitting HTTP messages. * @param pSize size of socket buffer */ public final J4pClientBuilder socketBufferSize(int pSize) { socketBufferSize = pSize; return this; } /** * Use the given cookie store. This useful is some form baed authentication had to be performed. * * @param pCookieStore cookiestore containing the cookies to send for requests. */ public final J4pClientBuilder cookieStore(CookieStore pCookieStore) { cookieStore = pCookieStore; return this; } /** * Set the authenticator for this client * * @param pAuthenticator authenticator used for checking the given user and password (if any). */ public final J4pClientBuilder authenticator(J4pAuthenticator pAuthenticator) { authenticator = pAuthenticator; return this; } /** * Set the proxy for this client * * @param pProxy proxy definition in the format <code>http://user:pass@host:port</code> or <code>http://host:port</code> * Example: <code>http://tom:sEcReT@my.proxy.com:8080</code> */ public final J4pClientBuilder proxy(String pProxy) { httpProxy = parseProxySettings(pProxy); return this; } /** * Set the proxy for this client * * @param pProxyHost proxy hostname * @param pProxyPort proxy port number */ public final J4pClientBuilder proxy(String pProxyHost, int pProxyPort) { httpProxy = new Proxy(pProxyHost, pProxyPort); return this; } /** * Set the proxy for this client * * @param pProxyHost proxy hostname * @param pProxyPort proxy port number * @param pProxyUser proxy authentication username * @param pProxyPass proxy authentication password */ public final J4pClientBuilder proxy(String pProxyHost, int pProxyPort, String pProxyUser, String pProxyPass) { httpProxy = new Proxy(pProxyHost, pProxyPort, pProxyUser, pProxyPass); return this; } /** * Set the proxy for this client based on http_proxy system environment variable */ public final J4pClientBuilder useProxyFromEnvironment() { Map<String, String> env = System.getenv(); for (String key : env.keySet()) { if (key.equalsIgnoreCase("http_proxy")) { httpProxy = parseProxySettings(env.get(key)); break; } } return this; } /** * Set the response extractor to use for handling single responses. By default the JSON answer from * the agent is parsed and only considered as successful if the status code returned is 200. In all other * cases an exception is thrown. An alternative extractor e.g. could silently ignored non existent MBeans (which * might be considered optional. * * @param pResponseExtractor response extractor to use. */ public final J4pClientBuilder responseExtractor(J4pResponseExtractor pResponseExtractor) { this.responseExtractor = pResponseExtractor; return this; } // ===================================================================================== /** * Build the agent with the information given before * * @return a new J4pClient */ public J4pClient build() { return new J4pClient(url, createHttpClient(), targetUrl != null ? new J4pTargetConfig(targetUrl, targetUser, targetPassword) : null, responseExtractor); } public HttpClient createHttpClient() { HttpClientConnectionManager connManager = pooledConnections ? createPoolingConnectionManager() : createBasicConnectionManager(); HttpClientBuilder builder = HttpClients.custom().setConnectionManager(connManager) .setDefaultCookieStore(cookieStore) .setUserAgent("Jolokia JMX-Client (using Apache-HttpClient/" + getVersionInfo() + ")") .setDefaultRequestConfig(createRequestConfig()); if (user != null && authenticator != null) { authenticator.authenticate(builder, user, password); } setupProxyIfNeeded(builder); return builder.build(); } /** * Parse proxy specification and return a proxy object representing the proxy configuration. * @param spec specification of for a proxy * @return proxy object or null if none is set */ static Proxy parseProxySettings(String spec) { try { if (spec == null || spec.length() == 0) { return null; } return new Proxy(spec); } catch (URISyntaxException e) { return null; } } // ========================================================================================== private void setupProxyIfNeeded(HttpClientBuilder builder) { if (httpProxy != null) { builder.setProxy(new HttpHost(httpProxy.getHost(), httpProxy.getPort())); if (httpProxy.getUser() != null) { AuthScope proxyAuthScope = new AuthScope(httpProxy.getHost(), httpProxy.getPort()); UsernamePasswordCredentials proxyCredentials = new UsernamePasswordCredentials(httpProxy.getUser(), httpProxy.getPass()); CredentialsProvider credentialsProvider = new BasicCredentialsProvider(); credentialsProvider.setCredentials(proxyAuthScope, proxyCredentials); builder.setDefaultCredentialsProvider(credentialsProvider); } } } private String getVersionInfo() { // determine the release version from packaged version info final VersionInfo vi = VersionInfo.loadVersionInfo("org.apache.http.client", getClass().getClassLoader()); return (vi != null) ? vi.getRelease() : VersionInfo.UNAVAILABLE; } private RequestConfig createRequestConfig() { RequestConfig.Builder requestConfigB = RequestConfig.custom(); requestConfigB.setExpectContinueEnabled(expectContinue); if (socketTimeout > -1) { requestConfigB.setSocketTimeout(socketTimeout); } if (connectionTimeout > -1) { requestConfigB.setConnectTimeout(connectionTimeout); } if (maxConnectionPoolTimeout > -1) { requestConfigB.setConnectionRequestTimeout(maxConnectionPoolTimeout); } return requestConfigB.build(); } private BasicHttpClientConnectionManager createBasicConnectionManager() { BasicHttpClientConnectionManager connManager = new BasicHttpClientConnectionManager( getSocketFactoryRegistry(), getConnectionFactory()); connManager.setSocketConfig(createSocketConfig()); connManager.setConnectionConfig(createConnectionConfig()); return connManager; } private PoolingHttpClientConnectionManager createPoolingConnectionManager() { PoolingHttpClientConnectionManager connManager = new PoolingHttpClientConnectionManager( getSocketFactoryRegistry(), getConnectionFactory()); connManager.setDefaultSocketConfig(createSocketConfig()); connManager.setDefaultConnectionConfig(createConnectionConfig()); if (maxTotalConnections != 0) { connManager.setMaxTotal(maxTotalConnections); } return connManager; } private ConnectionConfig createConnectionConfig() { return ConnectionConfig.custom().setBufferSize(socketBufferSize).setCharset(contentCharset).build(); } private SocketConfig createSocketConfig() { SocketConfig.Builder socketConfigB = SocketConfig.custom(); if (socketTimeout >= 0) { socketConfigB.setSoTimeout(socketTimeout); } socketConfigB.setTcpNoDelay(tcpNoDelay); return socketConfigB.build(); } private Registry<ConnectionSocketFactory> getSocketFactoryRegistry() { SSLContext sslcontext = SSLContexts.createSystemDefault(); X509HostnameVerifier hostnameVerifier = new BrowserCompatHostnameVerifier(); return RegistryBuilder.<ConnectionSocketFactory>create() .register("http", PlainConnectionSocketFactory.INSTANCE) .register("https", new SSLConnectionSocketFactory(sslcontext, hostnameVerifier)).build(); } private HttpConnectionFactory<HttpRoute, ManagedHttpClientConnection> getConnectionFactory() { return new ManagedHttpClientConnectionFactory(new DefaultHttpRequestWriterFactory(), new DefaultHttpResponseParserFactory()); } /** * Internal representation of proxy server. Package protected so that it can be accessed by tests. */ static class Proxy { private String host; private int port; private String user; private String pass; public Proxy(String host, int port) { this(host, port, null, null); } public Proxy(String host, int port, String user, String pass) { this.host = host; this.port = port; this.user = user; this.pass = pass; } /** * Create a proxy object from the environment * * @param env environment variable to parse * @throws URISyntaxException if the given env var is not a valid proxy specification */ public Proxy(String env) throws URISyntaxException { String colon = ":"; URI uri = new URI(env); this.host = uri.getHost(); this.port = uri.getPort(); if (host == null || host.isEmpty() || port < 0 || port > 65535) { throw new URISyntaxException(env, "Invalid host '" + host + "' or port " + port); } String userInfo = uri.getUserInfo(); if (userInfo != null && !userInfo.isEmpty()) { if (userInfo.contains(colon)) { this.user = userInfo.substring(0, userInfo.indexOf(colon)); this.pass = userInfo.substring(userInfo.indexOf(colon) + 1); } else { this.user = userInfo; } } } public String getHost() { return host; } public int getPort() { return port; } public String getUser() { return user; } public String getPass() { return pass; } } }