Java tutorial
/* * jabsorb - a Java to JavaScript Advanced Object Request Broker * http://www.jabsorb.org * * Copyright 2007-2009 The jabsorb team * * based on original code from * JSON-RPC-Java - a JSON-RPC to Java Bridge with dynamic invocation * * Copyright Metaparadigm Pte. Ltd. 2004. * Michael Clark <michael@metaparadigm.com> * * 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. * */ package org.jabsorb.serializer.impl; import java.util.AbstractSet; import java.util.HashSet; import java.util.Iterator; import java.util.LinkedHashSet; import java.util.Set; import java.util.TreeSet; import org.jabsorb.serializer.AbstractSerializer; import org.jabsorb.serializer.MarshallException; import org.jabsorb.serializer.ObjectMatch; import org.jabsorb.serializer.SerializerState; import org.jabsorb.serializer.UnmarshallException; import org.jabsorb.JSONSerializer; import org.json.JSONException; import org.json.JSONObject; /** * Serialises Sets * * TODO: if this serialises a superclass does it need to also specify the * subclasses? */ public class SetSerializer extends AbstractSerializer { /** * Unique serialisation id. */ private final static long serialVersionUID = 2; /** * Classes that this can serialise. */ private static Class[] _serializableClasses = new Class[] { Set.class, HashSet.class, TreeSet.class, LinkedHashSet.class }; /** * Classes that this can serialise to. */ private static Class[] _JSONClasses = new Class[] { JSONObject.class }; public boolean canSerialize(Class clazz, Class jsonClazz) { return (super.canSerialize(clazz, jsonClazz) || ((jsonClazz == null || jsonClazz == JSONObject.class) && Set.class.isAssignableFrom(clazz))); } public Class[] getJSONClasses() { return _JSONClasses; } public Class[] getSerializableClasses() { return _serializableClasses; } public Object marshall(SerializerState state, Object p, Object o) throws MarshallException { Set set = (Set) o; JSONObject obj = new JSONObject(); JSONObject setdata = new JSONObject(); if (ser.getMarshallClassHints()) { try { obj.put("javaClass", o.getClass().getName()); } catch (JSONException e) { throw new MarshallException("javaClass not found!", e); } } try { obj.put("set", setdata); state.push(o, setdata, "set"); } catch (JSONException e) { throw new MarshallException("Could not set 'set': " + e.getMessage(), e); } Object key = null; Iterator i = set.iterator(); try { while (i.hasNext()) { key = i.next(); String keyString = key.toString(); // only support String keys Object json = ser.marshall(state, setdata, key, keyString); // omit the object entirely if it's a circular reference or duplicate // it will be regenerated in the fixups phase if (JSONSerializer.CIRC_REF_OR_DUPLICATE != json) { setdata.put(keyString, json); } } } catch (MarshallException e) { throw new MarshallException("set key " + key + e.getMessage(), e); } catch (JSONException e) { throw new MarshallException("set key " + key + e.getMessage(), e); } finally { state.pop(); } return obj; } public ObjectMatch tryUnmarshall(SerializerState state, Class clazz, Object o) throws UnmarshallException { JSONObject jso = (JSONObject) o; String java_class; try { java_class = jso.getString("javaClass"); } catch (JSONException e) { throw new UnmarshallException("Could not read javaClass", e); } if (java_class == null) { throw new UnmarshallException("no type hint"); } if (!(java_class.equals("java.util.Set") || java_class.equals("java.util.AbstractSet") || java_class.equals("java.util.LinkedHashSet") || java_class.equals("java.util.TreeSet") || java_class.equals("java.util.HashSet"))) { throw new UnmarshallException("not a Set"); } JSONObject jsonset; try { jsonset = jso.getJSONObject("set"); } catch (JSONException e) { throw new UnmarshallException("set missing", e); } if (jsonset == null) { throw new UnmarshallException("set missing"); } ObjectMatch m = new ObjectMatch(-1); state.setSerialized(o, m); Iterator i = jsonset.keys(); String key = null; try { while (i.hasNext()) { key = (String) i.next(); m.setMismatch(ser.tryUnmarshall(state, null, jsonset.get(key)).max(m).getMismatch()); } } catch (UnmarshallException e) { throw new UnmarshallException("key " + key + " " + e.getMessage(), e); } catch (JSONException e) { throw new UnmarshallException("key " + key + " " + e.getMessage(), e); } return m; } public Object unmarshall(SerializerState state, Class clazz, Object o) throws UnmarshallException { JSONObject jso = (JSONObject) o; String java_class; try { java_class = jso.getString("javaClass"); } catch (JSONException e) { throw new UnmarshallException("Could not read javaClass", e); } if (java_class == null) { throw new UnmarshallException("no type hint"); } AbstractSet abset = null; if (java_class.equals("java.util.Set") || java_class.equals("java.util.AbstractSet") || java_class.equals("java.util.HashSet")) { abset = new HashSet(); } else if (java_class.equals("java.util.TreeSet")) { abset = new TreeSet(); } else if (java_class.equals("java.util.LinkedHashSet")) { abset = new LinkedHashSet(); } else { throw new UnmarshallException("not a Set"); } JSONObject jsonset; try { jsonset = jso.getJSONObject("set"); } catch (JSONException e) { throw new UnmarshallException("set missing", e); } if (jsonset == null) { throw new UnmarshallException("set missing"); } Iterator i = jsonset.keys(); String key = null; state.setSerialized(o, abset); try { while (i.hasNext()) { key = (String) i.next(); Object setElement = jsonset.get(key); abset.add(ser.unmarshall(state, null, setElement)); } } catch (UnmarshallException e) { throw new UnmarshallException("key " + i + e.getMessage(), e); } catch (JSONException e) { throw new UnmarshallException("key " + key + " " + e.getMessage(), e); } return abset; } }