Java tutorial
package org.i3xx.step.uno.impl.service.builtin; /* * #%L * NordApp OfficeBase :: uno * %% * Copyright (C) 2014 - 2015 I.D.S. DialogSysteme GmbH * %% * 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. * #L% */ import java.io.ByteArrayInputStream; import java.io.ByteArrayOutputStream; import java.io.ObjectInputStream; import java.io.ObjectOutputStream; import java.io.Serializable; import java.util.Iterator; import java.util.LinkedHashMap; import java.util.Map; import org.apache.commons.codec.binary.Base64; import org.i3xx.step.uno.impl.ContextImpl; import org.i3xx.step.uno.impl.ContextImpl.ContextService; import org.i3xx.step.uno.impl.util.GsonHashMapDeserializer; import org.i3xx.step.uno.model.service.builtin.BuiltinService; import org.mozilla.javascript.Callable; import org.mozilla.javascript.Context; import org.mozilla.javascript.NativeJSON; import org.mozilla.javascript.Scriptable; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.google.gson.Gson; import com.google.gson.GsonBuilder; /** * Use this service to administer the context * * @author Stefan * */ public class ContextAdministrationService implements BuiltinService { private static Logger logger = LoggerFactory.getLogger(ContextAdministrationService.class); private ContextImpl.ContextService context; public ContextAdministrationService(ContextImpl.ContextService context) { this.context = context; } public void initialize() { //not implemented yet } public void deactivate() { //not implemented yet } public void reinitialize(ContextService context) { this.context = context; } /** * Clears the values of the context. */ public void clearValues() { context.getValues().clear(); } /** * Writes the key value map to a JSON String * * @return The JSON String * @throws Exception */ public String toJSON() throws Exception { Gson gson = new Gson(); StringBuffer buffer = new StringBuffer(); Map<String, Object> values = context.getValues(); if (logger.isDebugEnabled()) { Iterator<Map.Entry<String, Object>> tempI = context.getValues().entrySet().iterator(); while (tempI.hasNext()) { Map.Entry<String, Object> e = tempI.next(); logger.debug("JSON object key:{}, value:{}, class:{}", e.getKey(), e.getValue(), e.getValue() == null ? "null" : e.getValue().getClass()); } } Context jscx = Context.getCurrentContext(); boolean jsf = jscx != null; if (!jsf) jscx = Context.enter(); Iterator<String> keys = values.keySet().iterator(); while (keys.hasNext()) { String key = keys.next(); buffer.append(','); buffer.append(gson.toJson(key)); buffer.append(':'); Object val = values.get(key); if (val == null) { buffer.append(gson.toJson(null)); } else if (val instanceof Number) { buffer.append(gson.toJson(val)); } else if (val instanceof String) { buffer.append(gson.toJson(val)); } else if (val instanceof Scriptable) { Scriptable scope = context.getScope(); Scriptable object = (Scriptable) val; String stmt = (String) NativeJSON.stringify(Context.getCurrentContext(), scope, object, null, null); buffer.append('{'); buffer.append(gson.toJson("Scriptable")); buffer.append(':'); buffer.append(gson.toJson(stmt)); buffer.append('}'); } else if (val instanceof Serializable) { buffer.append('{'); buffer.append(gson.toJson("Object")); buffer.append(':'); byte[] buf = readValue(val); if (buf == null) continue; String stmt = Base64.encodeBase64URLSafeString(buf); buffer.append(gson.toJson(stmt)); buffer.append('}'); } else { //error } //fi } if (buffer.length() > 0) { buffer.setCharAt(0, '{'); } else { buffer.append('{'); } buffer.append('}'); if (!jsf) Context.exit(); return buffer.toString(); } /** * Reads the key value pairs from a JSON String, clears the existing map * and puts the pairs into the map. * * @param json * @throws Exception */ public void fromJSON(String json) throws Exception { Map<String, Object> values = context.getValues(); values.clear(); GsonBuilder gsonBuilder = new GsonBuilder(); gsonBuilder.registerTypeAdapter(LinkedHashMap.class, new GsonHashMapDeserializer()); Gson gson = gsonBuilder.create(); final Callable rev = new Callable() { public Object call(Context cx, Scriptable scope, Scriptable thisObj, Object[] args) { // // sh, 12.12.2014 // not really understood what happens, but // @see http://stackoverflow.com/questions/10856154/rhino-return-json-from-within-java // tested some toJSON/fromJSON sequences with success. // return args[1]; } }; Context jscx = Context.getCurrentContext(); boolean jsf = jscx != null; if (!jsf) jscx = Context.enter(); LinkedHashMap<?, ?> map = gson.fromJson(json, LinkedHashMap.class); Iterator<?> iter = map.keySet().iterator(); while (iter.hasNext()) { String key = (String) iter.next(); Object val = map.get(key); if (val == null) { //values.put(key, null); } else if (val instanceof Number) { values.put(key, val); } else if (val instanceof String) { values.put(key, val); } else if (val instanceof Map<?, ?>) { LinkedHashMap<?, ?> mo2 = (LinkedHashMap<?, ?>) val; if (mo2.containsKey("Object")) { String stmt = (String) mo2.get("Object"); if (stmt != null) { Object obj = writeValue(Base64.decodeBase64(stmt)); if (obj != null) { values.put(key, obj); } //fi } //fi } else if (mo2.containsKey("Scriptable")) { String stmt = (String) mo2.get("Scriptable"); if (stmt != null) { Scriptable scope = context.getScope(); Object obj = NativeJSON.parse(jscx, scope, stmt, rev); if (obj != null) { values.put(key, obj); } //fi } //fi } else { continue; } } //fi } //while if (!jsf) Context.exit(); } /**/ private byte[] readValue(Object val) throws Exception { if (val == null) return null; ByteArrayOutputStream buffer = new ByteArrayOutputStream(); ObjectOutputStream out = new ObjectOutputStream(buffer); out.writeObject(val); out.close(); return buffer.toByteArray(); } /**/ private Object writeValue(byte[] buffer) throws Exception { if (buffer == null) return null; ObjectInputStream in = new ObjectInputStream(new ByteArrayInputStream(buffer)); Object val = (Object) in.readObject(); in.close(); return val; } }