Java tutorial
/* * Copyright 2011-15 Fraunhofer ISE * * This file is part of OpenMUC. * For more information visit http://www.openmuc.org * * OpenMUC 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 3 of the License, or * (at your option) any later version. * * OpenMUC 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 OpenMUC. If not, see <http://www.gnu.org/licenses/>. * */ package org.openmuc.framework.driver.rest; import java.io.IOException; import java.io.InputStream; import java.io.OutputStreamWriter; import java.net.HttpURLConnection; import java.net.MalformedURLException; import java.net.URL; import java.net.URLConnection; import java.security.KeyManagementException; import java.security.NoSuchAlgorithmException; import java.util.List; import javax.net.ssl.HostnameVerifier; import javax.net.ssl.HttpsURLConnection; import javax.net.ssl.SSLContext; import javax.net.ssl.SSLSession; import javax.net.ssl.TrustManager; import javax.net.ssl.X509TrustManager; import org.apache.commons.codec.binary.Base64; import org.openmuc.framework.config.ChannelScanInfo; import org.openmuc.framework.data.BooleanValue; import org.openmuc.framework.data.ByteArrayValue; import org.openmuc.framework.data.ByteValue; import org.openmuc.framework.data.DoubleValue; import org.openmuc.framework.data.FloatValue; import org.openmuc.framework.data.IntValue; import org.openmuc.framework.data.LongValue; import org.openmuc.framework.data.Record; import org.openmuc.framework.data.ShortValue; import org.openmuc.framework.data.StringValue; import org.openmuc.framework.data.Value; import org.openmuc.framework.data.ValueType; import org.openmuc.framework.driver.rest.helper.JsonWrapper; import org.openmuc.framework.driver.spi.ChannelRecordContainer; import org.openmuc.framework.driver.spi.ChannelValueContainer; import org.openmuc.framework.driver.spi.Connection; import org.openmuc.framework.driver.spi.ConnectionException; import org.openmuc.framework.driver.spi.RecordsReceivedListener; public class RestConnection implements Connection { private JsonWrapper wrapper; private URL url; private URLConnection con; private String deviceAddress; private int timeout; private boolean isHTTPS; private String authString; // private final static Logger logger = LoggerFactory.getLogger(RestConnection.class); public RestConnection(String deviceAddress, String credentials, int timeout) throws ConnectionException { this.timeout = timeout; wrapper = new JsonWrapper(); authString = new String(Base64.encodeBase64(credentials.getBytes())); if (!deviceAddress.endsWith("/")) { this.deviceAddress = deviceAddress + "/channels/"; } else { this.deviceAddress = deviceAddress + "channels/"; } if (deviceAddress.startsWith("https://")) { isHTTPS = true; } else { isHTTPS = false; } if (isHTTPS) { TrustManager[] trustAllCerts = new TrustManager[] { new X509TrustManager() { @Override public java.security.cert.X509Certificate[] getAcceptedIssuers() { return null; } @Override public void checkClientTrusted(java.security.cert.X509Certificate[] certs, String authType) { } @Override public void checkServerTrusted(java.security.cert.X509Certificate[] certs, String authType) { } } }; try { SSLContext sc = SSLContext.getInstance("SSL"); sc.init(null, trustAllCerts, new java.security.SecureRandom()); HttpsURLConnection.setDefaultSSLSocketFactory(sc.getSocketFactory()); } catch (KeyManagementException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } // Create all-trusting host name verifier HostnameVerifier allHostsValid = new HostnameVerifier() { @Override public boolean verify(String hostname, SSLSession session) { return true; } }; HttpsURLConnection.setDefaultHostnameVerifier(allHostsValid); // HttpsURLConnection.setFollowRedirects(false); } } public Record readChannel(String channelAddress, ValueType valueType) throws ConnectionException { Record newRecord = null; try { newRecord = wrapper.toRecord(get(channelAddress), valueType); } catch (IOException e) { e.printStackTrace(); throw new ConnectionException(e.getMessage()); } return newRecord; } public List<ChannelScanInfo> readChannels() throws ConnectionException { List<ChannelScanInfo> remoteChannels = null; try { remoteChannels = wrapper.toChannelList(get("")); } catch (IOException e) { e.printStackTrace(); throw new ConnectionException(e.getMessage()); } return remoteChannels; } public void writeChannel(String channelAddress, Value value, ValueType valueType) throws ConnectionException { Record remoteRecord = new Record(value, System.currentTimeMillis()); put(channelAddress, wrapper.fromRecord(remoteRecord, valueType)); } public void connect() throws ConnectionException { try { url = new URL(deviceAddress); con = url.openConnection(); con.setRequestProperty("Connection", "Keep-Alive"); con.setConnectTimeout(timeout); con.setReadTimeout(timeout); } catch (MalformedURLException e) { e.printStackTrace(); throw new ConnectionException("malformed URL: " + deviceAddress); } catch (IOException e) { throw new ConnectionException(e.getMessage()); } try { con.connect(); checkResponseCode(con); } catch (IOException e) { throw new ConnectionException(e.getMessage()); } } private InputStream get(String suffix) throws ConnectionException { InputStream stream = null; try { url = new URL(deviceAddress + suffix); con = url.openConnection(); con.setRequestProperty("Connection", "Keep-Alive"); con.setConnectTimeout(timeout); con.setReadTimeout(timeout); stream = con.getInputStream(); } catch (MalformedURLException e) { e.printStackTrace(); throw new ConnectionException("malformed URL: " + deviceAddress); } catch (IOException e) { e.printStackTrace(); throw new ConnectionException(e.getMessage()); } checkResponseCode(con); return stream; } private void put(String suffix, String output) throws ConnectionException { try { url = new URL(deviceAddress + suffix); con = url.openConnection(); con.setConnectTimeout(timeout); con.setDoOutput(true); con.setRequestProperty("Connection", "Keep-Alive"); con.setRequestProperty("Content-Type", "application/json"); con.setRequestProperty("Accept", "application/json"); con.setRequestProperty("Authorization", "Basic " + authString); con.setReadTimeout(timeout); if (isHTTPS) { ((HttpsURLConnection) con).setRequestMethod("PUT"); } else { ((HttpURLConnection) con).setRequestMethod("PUT"); } OutputStreamWriter out = new OutputStreamWriter(con.getOutputStream()); out.write(output); out.close(); } catch (MalformedURLException e) { e.printStackTrace(); throw new ConnectionException("malformed URL: " + deviceAddress); } catch (IOException e) { e.printStackTrace(); throw new ConnectionException(e.getMessage()); } checkResponseCode(con); } private void checkResponseCode(URLConnection con) throws ConnectionException { int respCode; try { if (isHTTPS) { respCode = ((HttpsURLConnection) con).getResponseCode(); if (!(respCode >= 200 && respCode < 300)) { throw new ConnectionException( "HTTPS " + respCode + ":" + ((HttpsURLConnection) con).getResponseMessage()); } } else { respCode = ((HttpURLConnection) con).getResponseCode(); if (!(respCode >= 200 && respCode < 300)) { throw new ConnectionException( "HTTP " + respCode + ":" + ((HttpURLConnection) con).getResponseMessage()); } } } catch (IOException e) { e.printStackTrace(); throw new ConnectionException(e.getMessage()); } } @Override public void disconnect() { if (isHTTPS) { ((HttpsURLConnection) con).disconnect(); } else { ((HttpURLConnection) con).disconnect(); } } @Override public Object read(List<ChannelRecordContainer> container, Object obj, String arg3) throws UnsupportedOperationException, ConnectionException { for (ChannelRecordContainer cont : container) { Record record = readChannel(cont.getChannelAddress(), cont.getChannel().getValueType()); if (record != null) { cont.setRecord(record); } } return null; } @Override public List<ChannelScanInfo> scanForChannels(String settings) throws UnsupportedOperationException, ConnectionException { return readChannels(); } @Override public void startListening(List<ChannelRecordContainer> arg1, RecordsReceivedListener arg2) throws UnsupportedOperationException, ConnectionException { throw new UnsupportedOperationException(); } @Override public Object write(List<ChannelValueContainer> container, Object containerListHandle) throws UnsupportedOperationException, ConnectionException { for (ChannelValueContainer cont : container) { Value value = cont.getValue(); if (value instanceof DoubleValue) { writeChannel(cont.getChannelAddress(), cont.getValue(), ValueType.DOUBLE); } else if (value instanceof StringValue) { writeChannel(cont.getChannelAddress(), cont.getValue(), ValueType.STRING); } else if (value instanceof ByteArrayValue) { writeChannel(cont.getChannelAddress(), cont.getValue(), ValueType.BYTE_ARRAY); } else if (value instanceof LongValue) { writeChannel(cont.getChannelAddress(), cont.getValue(), ValueType.LONG); } else if (value instanceof BooleanValue) { writeChannel(cont.getChannelAddress(), cont.getValue(), ValueType.BOOLEAN); } else if (value instanceof FloatValue) { writeChannel(cont.getChannelAddress(), cont.getValue(), ValueType.FLOAT); } else if (value instanceof IntValue) { writeChannel(cont.getChannelAddress(), cont.getValue(), ValueType.INTEGER); } else if (value instanceof ShortValue) { writeChannel(cont.getChannelAddress(), cont.getValue(), ValueType.SHORT); } else if (value instanceof ByteValue) { writeChannel(cont.getChannelAddress(), cont.getValue(), ValueType.BYTE); } } return null; } }