Java tutorial
/* * ==================================================================== * * Intersection Engine * * Copyright (C) 2007 - 2011 GeoSolutions S.A.S. * http://www.geo-solutions.it * * GPLv3 + Classpath exception * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. * * ==================================================================== * * This software consists of voluntary contributions made by developers * of GeoSolutions. For more information on GeoSolutions, please see * <http://www.geo-solutions.it/>. * */ package it.geosolutions.figis.requester; import java.io.File; import java.io.IOException; import java.io.InputStream; import java.io.UnsupportedEncodingException; import java.net.ConnectException; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL; import org.apache.commons.httpclient.Credentials; import org.apache.commons.httpclient.HttpClient; import org.apache.commons.httpclient.HttpStatus; import org.apache.commons.httpclient.UsernamePasswordCredentials; import org.apache.commons.httpclient.auth.AuthScope; import org.apache.commons.httpclient.methods.DeleteMethod; import org.apache.commons.httpclient.methods.EntityEnclosingMethod; import org.apache.commons.httpclient.methods.FileRequestEntity; import org.apache.commons.httpclient.methods.GetMethod; import org.apache.commons.httpclient.methods.PostMethod; import org.apache.commons.httpclient.methods.PutMethod; import org.apache.commons.httpclient.methods.RequestEntity; import org.apache.commons.httpclient.methods.StringRequestEntity; import org.apache.commons.io.IOUtils; import org.apache.log4j.Level; import org.apache.log4j.Logger; /** * Low level HTTP utilities. */ class HTTPUtils { private static final Logger LOGGER = Logger.getLogger(HTTPUtils.class); /** * Performs an HTTP GET on the given URL. * * @param url The URL where to connect to. * @return The HTTP response as a String if the HTTP response code was 200 (OK). * @throws MalformedURLException */ public static String get(String url) throws MalformedURLException { return get(url, null, null); } /** * Performs an HTTP GET on the given URL. * <BR>Basic auth is used if both username and pw are not null. * * @param url The URL where to connect to. * @param username Basic auth credential. No basic auth if null. * @param pw Basic auth credential. No basic auth if null. * @return The HTTP response as a String if the HTTP response code was 200 (OK). * @throws MalformedURLException */ public static String get(String url, String username, String pw) throws MalformedURLException { GetMethod httpMethod = null; try { HttpClient client = new HttpClient(); setAuth(client, url, username, pw); httpMethod = new GetMethod(url); client.getHttpConnectionManager().getParams().setConnectionTimeout(5000); int status = client.executeMethod(httpMethod); if (status == HttpStatus.SC_OK) { InputStream is = httpMethod.getResponseBodyAsStream(); String response = IOUtils.toString(is); if (response.trim().length() == 0) // sometime gs rest fails { LOGGER.warn("ResponseBody is empty"); return null; } else { return response; } } else { LOGGER.info("(" + status + ") " + HttpStatus.getStatusText(status) + " -- " + url); } } catch (ConnectException e) { LOGGER.error("Couldn't connect to [" + url + "]", e); } catch (IOException e) { LOGGER.error("Error talking to [" + url + "]", e); } finally { if (httpMethod != null) { httpMethod.releaseConnection(); } } return null; } /** * PUTs a File to the given URL. * <BR>Basic auth is used if both username and pw are not null. * * @param url The URL where to connect to. * @param file The File to be sent. * @param contentType The content-type to advert in the PUT. * @param username Basic auth credential. No basic auth if null. * @param pw Basic auth credential. No basic auth if null. * @return The HTTP response as a String if the HTTP response code was 200 (OK). * @throws MalformedURLException * @return the HTTP response or <TT>null</TT> on errors. */ public static String put(String url, File file, String contentType, String username, String pw) { return put(url, new FileRequestEntity(file, contentType), username, pw); } /** * PUTs a String to the given URL. * <BR>Basic auth is used if both username and pw are not null. * * @param url The URL where to connect to. * @param content The content to be sent as a String. * @param contentType The content-type to advert in the PUT. * @param username Basic auth credential. No basic auth if null. * @param pw Basic auth credential. No basic auth if null. * @return The HTTP response as a String if the HTTP response code was 200 (OK). * @throws MalformedURLException * @return the HTTP response or <TT>null</TT> on errors. */ public static String put(String url, String content, String contentType, String username, String pw) { try { return put(url, new StringRequestEntity(content, contentType, null), username, pw); } catch (UnsupportedEncodingException ex) { LOGGER.error("Cannot PUT " + url, ex); return null; } } /** * PUTs a String representing an XML document to the given URL. * <BR>Basic auth is used if both username and pw are not null. * * @param url The URL where to connect to. * @param content The XML content to be sent as a String. * @param username Basic auth credential. No basic auth if null. * @param pw Basic auth credential. No basic auth if null. * @return The HTTP response as a String if the HTTP response code was 200 (OK). * @throws MalformedURLException * @return the HTTP response or <TT>null</TT> on errors. */ public static String putXml(String url, String content, String username, String pw) { return put(url, content, "text/xml", username, pw); } /** * Performs a PUT to the given URL. * <BR>Basic auth is used if both username and pw are not null. * * @param url The URL where to connect to. * @param requestEntity The request to be sent. * @param username Basic auth credential. No basic auth if null. * @param pw Basic auth credential. No basic auth if null. * @return The HTTP response as a String if the HTTP response code was 200 (OK). * @throws MalformedURLException * @return the HTTP response or <TT>null</TT> on errors. */ public static String put(String url, RequestEntity requestEntity, String username, String pw) { return send(new PutMethod(url), url, requestEntity, username, pw); } /** * POSTs a File to the given URL. * <BR>Basic auth is used if both username and pw are not null. * * @param url The URL where to connect to. * @param file The File to be sent. * @param contentType The content-type to advert in the POST. * @param username Basic auth credential. No basic auth if null. * @param pw Basic auth credential. No basic auth if null. * @return The HTTP response as a String if the HTTP response code was 200 (OK). * @throws MalformedURLException * @return the HTTP response or <TT>null</TT> on errors. */ public static String post(String url, File file, String contentType, String username, String pw) { return post(url, new FileRequestEntity(file, contentType), username, pw); } /** * POSTs a String to the given URL. * <BR>Basic auth is used if both username and pw are not null. * * @param url The URL where to connect to. * @param content The content to be sent as a String. * @param contentType The content-type to advert in the POST. * @param username Basic auth credential. No basic auth if null. * @param pw Basic auth credential. No basic auth if null. * @return The HTTP response as a String if the HTTP response code was 200 (OK). * @throws MalformedURLException * @return the HTTP response or <TT>null</TT> on errors. */ public static String post(String url, String content, String contentType, String username, String pw) { try { return post(url, new StringRequestEntity(content, contentType, null), username, pw); } catch (UnsupportedEncodingException ex) { LOGGER.error("Cannot POST " + url, ex); return null; } } /** * POSTs a String representing an XML document to the given URL. * <BR>Basic auth is used if both username and pw are not null. * * @param url The URL where to connect to. * @param content The XML content to be sent as a String. * @param username Basic auth credential. No basic auth if null. * @param pw Basic auth credential. No basic auth if null. * @return The HTTP response as a String if the HTTP response code was 200 (OK). * @throws MalformedURLException * @return the HTTP response or <TT>null</TT> on errors. */ public static String postXml(String url, String content, String username, String pw) { return post(url, content, "text/xml", username, pw); } /** * Performs a POST to the given URL. * <BR>Basic auth is used if both username and pw are not null. * * @param url The URL where to connect to. * @param requestEntity The request to be sent. * @param username Basic auth credential. No basic auth if null. * @param pw Basic auth credential. No basic auth if null. * @return The HTTP response as a String if the HTTP response code was 200 (OK). * @throws MalformedURLException * @return the HTTP response or <TT>null</TT> on errors. */ public static String post(String url, RequestEntity requestEntity, String username, String pw) { return send(new PostMethod(url), url, requestEntity, username, pw); } /** * Send an HTTP request (PUT or POST) to a server. * <BR>Basic auth is used if both username and pw are not null. * <P> * Only <UL> * <LI>200: OK</LI> * <LI>201: ACCEPTED</LI> * <LI>202: CREATED</LI> * </UL> are accepted as successful codes; in these cases the response string will be returned. * * @return the HTTP response or <TT>null</TT> on errors. */ private static String send(final EntityEnclosingMethod httpMethod, String url, RequestEntity requestEntity, String username, String pw) { try { HttpClient client = new HttpClient(); setAuth(client, url, username, pw); client.getHttpConnectionManager().getParams().setConnectionTimeout(5000); if (requestEntity != null) { httpMethod.setRequestEntity(requestEntity); } int status = client.executeMethod(httpMethod); switch (status) { case HttpURLConnection.HTTP_OK: case HttpURLConnection.HTTP_CREATED: case HttpURLConnection.HTTP_ACCEPTED: String response = IOUtils.toString(httpMethod.getResponseBodyAsStream()); if (LOGGER.isInfoEnabled()) { LOGGER.info("HTTP " + httpMethod.getStatusText() + ": " + response); } return response; default: LOGGER.warn("Bad response: code[" + status + "]" + " msg[" + httpMethod.getStatusText() + "]" + " url[" + url + "]" + " method[" + httpMethod.getClass().getSimpleName() + "]: " + IOUtils.toString(httpMethod.getResponseBodyAsStream())); return null; } } catch (ConnectException e) { LOGGER.error("Couldn't connect to [" + url + "]", e); return null; } catch (IOException e) { LOGGER.error("Error talking to " + url + " : " + e.getLocalizedMessage(), e); return null; } finally { if (httpMethod != null) { httpMethod.releaseConnection(); } } } public static boolean delete(String url, final String user, final String pw) { DeleteMethod httpMethod = null; try { HttpClient client = new HttpClient(); setAuth(client, url, user, pw); httpMethod = new DeleteMethod(url); client.getHttpConnectionManager().getParams().setConnectionTimeout(5000); int status = client.executeMethod(httpMethod); String response = ""; if (status == HttpStatus.SC_OK) { InputStream is = httpMethod.getResponseBodyAsStream(); response = IOUtils.toString(is); if (response.trim().equals("")) // sometimes gs rest fails { if (LOGGER.isDebugEnabled()) { LOGGER.debug( "ResponseBody is empty (this may be not an error since we just performed a DELETE call)"); } return true; } if (LOGGER.isDebugEnabled()) { LOGGER.debug("(" + status + ") " + httpMethod.getStatusText() + " -- " + url); } return true; } else { if (LOGGER.isInfoEnabled()) { LOGGER.info("(" + status + ") " + httpMethod.getStatusText() + " -- " + url); LOGGER.info("Response: '" + response + "'"); } } } catch (ConnectException e) { LOGGER.info("Couldn't connect to [" + url + "]", e); } catch (IOException e) { LOGGER.info("Error talking to [" + url + "]", e); } finally { if (httpMethod != null) { httpMethod.releaseConnection(); } } return false; } /** * @return true if the server response was an HTTP_OK */ public static boolean httpPing(String url) { return httpPing(url, null, null); } public static boolean httpPing(String url, String username, String pw) { GetMethod httpMethod = null; try { HttpClient client = new HttpClient(); setAuth(client, url, username, pw); httpMethod = new GetMethod(url); client.getHttpConnectionManager().getParams().setConnectionTimeout(2000); int status = client.executeMethod(httpMethod); if (status != HttpStatus.SC_OK) { LOGGER.warn("PING failed at '" + url + "': (" + status + ") " + httpMethod.getStatusText()); return false; } else { return true; } } catch (ConnectException e) { if (LOGGER.isInfoEnabled()) { LOGGER.log(Level.INFO, e.getLocalizedMessage(), e); } return false; } catch (IOException e) { if (LOGGER.isInfoEnabled()) { LOGGER.log(Level.INFO, e.getLocalizedMessage(), e); } return false; } finally { if (httpMethod != null) { httpMethod.releaseConnection(); } } } /** * Used to query for REST resources. * * @param url The URL of the REST resource to query about. * @param username * @param pw * @return true on 200, false on 404. * @throws RuntimeException on unhandled status or exceptions. */ public static boolean exists(String url, String username, String pw) { GetMethod httpMethod = null; try { HttpClient client = new HttpClient(); setAuth(client, url, username, pw); httpMethod = new GetMethod(url); client.getHttpConnectionManager().getParams().setConnectionTimeout(2000); int status = client.executeMethod(httpMethod); switch (status) { case HttpStatus.SC_OK: return true; case HttpStatus.SC_NOT_FOUND: return false; default: throw new RuntimeException("Unhandled response status at '" + url + "': (" + status + ") " + httpMethod.getStatusText()); } } catch (ConnectException e) { throw new RuntimeException(e); } catch (IOException e) { throw new RuntimeException(e); } finally { if (httpMethod != null) { httpMethod.releaseConnection(); } } } private static void setAuth(HttpClient client, String url, String username, String pw) throws MalformedURLException { URL u = new URL(url); if ((username != null) && (pw != null)) { Credentials defaultcreds = new UsernamePasswordCredentials(username, pw); client.getState().setCredentials(new AuthScope(u.getHost(), u.getPort()), defaultcreds); client.getParams().setAuthenticationPreemptive(true); // GS2 by default always requires authentication } else { if (LOGGER.isDebugEnabled()) { LOGGER.debug("Not setting credentials to access to " + url); } } } }