Java tutorial
/* * Licensed to the OpenNMS Group Inc. under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The OpenNMS Group Inc. licences this file to You 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. */ package org.opennms.xmlclient; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import java.io.OutputStream; import java.io.OutputStreamWriter; import java.io.Reader; import java.io.Writer; import java.net.HttpURLConnection; import java.net.ProtocolException; import java.net.URL; import java.net.URLConnection; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * OpenNmsXmlclient * This class implements in java similar functionality to the provision.pl script */ public class BasicHttpMethods { private Log log = LogFactory.getLog(BasicHttpMethods.class.getName()); /* ***************************************** * GETTERS AND SETTERS FOR CLASS PROPERTIES * *****************************************/ public Log getLog() { return log; } /** * @param log set commons Log for this class. Defaults to OpenNmsXmlClient.class.getName() if not set. */ public void setLog(Log log) { this.log = log; } /* ********************************************************************* * BASIC HTTP POST, DELETE PUT AND GET METHODS * See http://stackoverflow.com/questions/1051004/how-to-send-put-delete * *********************************************************************/ /** * Sends an HTTP GET request to a url * * @param endpoint - The URL of the server. (Example: " http://www.yahoo.com/search") * @param requestParameters - all the request parameters (Example: "param1=val1¶m2=val2"). Note: This method will add the question mark (?) to the request - DO NOT add it yourself * @return - The response from the end point */ public String sendGetRequest(String endpoint, String requestParameters, String username, String password) throws Exception { String result = null; if (endpoint.startsWith("http://")) { // Send a GET request to the servlet try { // Send data String urlStr = endpoint; if (requestParameters != null && requestParameters.length() > 0) { urlStr += "?" + requestParameters; } URL url = new URL(urlStr); URLConnection conn = url.openConnection(); // set username and password // see http://www.javaworld.com/javaworld/javatips/jw-javatip47.html String userPassword = username + ":" + password; // Encode String // String encoding = new sun.misc.BASE64Encoder().encode (userPassword.getBytes()); // depreciated sun.misc.BASE64Encoder() byte[] encoding = org.apache.commons.codec.binary.Base64.encodeBase64(userPassword.getBytes()); String authStringEnc = new String(encoding); log.debug("Base64 encoded auth string: '" + authStringEnc + "'"); conn.setRequestProperty("Authorization", "Basic " + authStringEnc); // Get the response BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream())); StringBuffer sb = new StringBuffer(); String line; while ((line = rd.readLine()) != null) { sb.append(line); } rd.close(); result = sb.toString(); } catch (Throwable e) { throw new Exception("problem issuing get to URL", e); } } return result; } /** * Reads data from the data reader and posts it to a server via POST request. * data - The data you want to send * endpoint - The server's address * output - writes the server's response to output * @throws Exception */ public void postData(Reader data, URL endpoint, Writer output, String username, String password) throws Exception { HttpURLConnection conn = null; try { conn = (HttpURLConnection) endpoint.openConnection(); try { conn.setRequestMethod("POST"); } catch (ProtocolException e) { throw new Exception("Shouldn't happen: HttpURLConnection doesn't support POST??", e); } // set username and password // see http://www.javaworld.com/javaworld/javatips/jw-javatip47.html String userPassword = username + ":" + password; // Encode String // String encoding = new sun.misc.BASE64Encoder().encode (userPassword.getBytes()); // depreciated sun.misc.BASE64Encoder() byte[] encoding = org.apache.commons.codec.binary.Base64.encodeBase64(userPassword.getBytes()); String authStringEnc = new String(encoding); log.debug("Base64 encoded auth string: '" + authStringEnc + "'"); conn.setRequestProperty("Authorization", "Basic " + authStringEnc); conn.setDoOutput(true); conn.setDoInput(true); conn.setUseCaches(false); conn.setAllowUserInteraction(false); conn.setRequestProperty("Content-type", "application/xml; charset=" + "UTF-8"); OutputStream out = conn.getOutputStream(); try { Writer writer = new OutputStreamWriter(out, "UTF-8"); pipe(data, writer); writer.close(); } catch (IOException e) { throw new Exception("IOException while posting data", e); } finally { if (out != null) out.close(); } InputStream in = conn.getInputStream(); try { Reader reader = new InputStreamReader(in); pipe(reader, output); reader.close(); } catch (IOException e) { throw new Exception("IOException while reading response", e); } finally { if (in != null) in.close(); } } catch (IOException e) { throw new Exception("Connection error (is server running at " + endpoint + " ?): " + e); } finally { if (conn != null) conn.disconnect(); } } /** * Pipes everything from the reader to the writer via a buffer */ private void pipe(Reader reader, Writer writer) throws IOException { char[] buf = new char[1024]; int read = 0; while ((read = reader.read(buf)) >= 0) { writer.write(buf, 0, read); } writer.flush(); } /** * Sends an HTTP DELETE request to a url * endpoint - The server's address * output - writes the server's response to output * @throws Exception */ public void deleteData(URL endpoint, Writer output, String username, String password) throws Exception { HttpURLConnection conn = null; try { conn = (HttpURLConnection) endpoint.openConnection(); try { conn.setRequestMethod("DELETE"); } catch (ProtocolException e) { throw new Exception("Shouldn't happen: HttpURLConnection doesn't support DELETE??", e); } // set username and password // see http://www.javaworld.com/javaworld/javatips/jw-javatip47.html String userPassword = username + ":" + password; // Encode String // String encoding = new sun.misc.BASE64Encoder().encode (userPassword.getBytes()); // depreciated sun.misc.BASE64Encoder() byte[] encoding = org.apache.commons.codec.binary.Base64.encodeBase64(userPassword.getBytes()); String authStringEnc = new String(encoding); log.debug("Base64 encoded auth string: '" + authStringEnc + "'"); conn.setRequestProperty("Authorization", "Basic " + authStringEnc); conn.setDoOutput(true); conn.setDoInput(true); conn.setUseCaches(false); conn.setAllowUserInteraction(false); conn.setRequestProperty("Content-type", "application/xml; charset=" + "UTF-8"); InputStream in = conn.getInputStream(); try { Reader reader = new InputStreamReader(in); pipe(reader, output); reader.close(); } catch (IOException e) { throw new Exception("IOException while reading response", e); } finally { if (in != null) in.close(); } } catch (IOException e) { throw new Exception("Connection error (is server running at " + endpoint + " ?): " + e); } finally { if (conn != null) conn.disconnect(); } } /** * sends data to a server via PUT request. * data - The data you want to send * endpoint - The server's address * output - writes the server's response to output * @throws Exception */ public void putData(Reader data, URL endpoint, Writer output, String username, String password) throws Exception { HttpURLConnection conn = null; try { conn = (HttpURLConnection) endpoint.openConnection(); try { conn.setRequestMethod("PUT"); } catch (ProtocolException e) { throw new Exception("Shouldn't happen: HttpURLConnection doesn't support PUT??", e); } // set username and password // see http://www.javaworld.com/javaworld/javatips/jw-javatip47.html String userPassword = username + ":" + password; // Encode String // String encoding = new sun.misc.BASE64Encoder().encode (userPassword.getBytes()); // depreciated sun.misc.BASE64Encoder() byte[] encoding = org.apache.commons.codec.binary.Base64.encodeBase64(userPassword.getBytes()); String authStringEnc = new String(encoding); log.debug("Base64 encoded auth string: '" + authStringEnc + "'"); conn.setRequestProperty("Authorization", "Basic " + authStringEnc); conn.setDoOutput(true); conn.setDoInput(true); conn.setUseCaches(false); conn.setAllowUserInteraction(false); conn.setRequestProperty("Content-type", "application/x-www-form-urlencoded; charset=" + "UTF-8"); OutputStream out = conn.getOutputStream(); try { Writer writer = new OutputStreamWriter(out, "UTF-8"); pipe(data, writer); writer.close(); } catch (IOException e) { throw new Exception("IOException while putting data", e); } finally { if (out != null) out.close(); } InputStream in = conn.getInputStream(); try { Reader reader = new InputStreamReader(in); pipe(reader, output); reader.close(); } catch (IOException e) { throw new Exception("IOException while reading response", e); } finally { if (in != null) in.close(); } } catch (IOException e) { throw new Exception("Connection error (is server running at " + endpoint + " ?): " + e); } finally { if (conn != null) conn.disconnect(); } } }