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.AbstractList; import java.util.ArrayList; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.Vector; import org.jabsorb.JSONSerializer; 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.json.JSONArray; import org.json.JSONException; import org.json.JSONObject; /** * Serialises lists * * TODO: if this serialises a superclass does it need to also specify the * subclasses? */ public class ListSerializer extends AbstractSerializer { /** * Unique serialisation id. */ private final static long serialVersionUID = 2; /** * Classes that this can serialise. */ private static Class[] _serializableClasses = new Class[] { List.class, ArrayList.class, LinkedList.class, Vector.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 || jsonClazz == JSONArray.class) && List.class.isAssignableFrom(clazz))); } public Class[] getJSONClasses() { return _JSONClasses; } public Class[] getSerializableClasses() { return _serializableClasses; } public Object marshall(SerializerState state, Object p, Object o) throws MarshallException { List list = (List) o; JSONObject obj = new JSONObject(); JSONArray arr = new JSONArray(); // TODO: this same block is done everywhere. // Have a single function to do it. if (ser.getMarshallClassHints()) { try { obj.put("javaClass", o.getClass().getName()); } catch (JSONException e) { throw new MarshallException("javaClass not found!", e); } } try { obj.put("list", arr); state.push(o, arr, "list"); } catch (JSONException e) { throw new MarshallException("Error setting list: " + e, e); } int index = 0; try { Iterator i = list.iterator(); while (i.hasNext()) { Object json = ser.marshall(state, arr, i.next(), new Integer(index)); if (JSONSerializer.CIRC_REF_OR_DUPLICATE != json) { arr.put(json); } else { // put a slot where the object would go, so it can be fixed up properly in the fix up phase arr.put(JSONObject.NULL); } index++; } } catch (MarshallException e) { throw new MarshallException("element " + index, e); } finally { state.pop(); } return arr; } // TODO: try unMarshall and unMarshall share 90% code. Put in into an // intermediate function. // TODO: Also cache the result somehow so that an unmarshall // following a tryUnmarshall doesn't do the same work twice! public ObjectMatch tryUnmarshall(SerializerState state, Class clazz, Object o) throws UnmarshallException { JSONObject jso = null; JSONArray jsonlist = null; if (o instanceof 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.List") || java_class.equals("java.util.AbstractList") || java_class.equals("java.util.LinkedList") || java_class.equals("java.util.ArrayList") || java_class .equals("java.util.Vector"))) { throw new UnmarshallException("not a List"); }*/ try { jsonlist = jso.getJSONArray("list"); } catch (JSONException e) { throw new UnmarshallException("Could not read list: " + e.getMessage(), e); } } else if (o instanceof JSONArray) { jsonlist = (JSONArray) o; } if (jsonlist == null) { throw new UnmarshallException("list missing"); } int i = 0; ObjectMatch m = new ObjectMatch(-1); state.setSerialized(o, m); try { for (; i < jsonlist.length(); i++) { m.setMismatch(ser.tryUnmarshall(state, null, jsonlist.get(i)).max(m).getMismatch()); } } catch (UnmarshallException e) { throw new UnmarshallException("element " + i + " " + e.getMessage(), e); } catch (JSONException e) { throw new UnmarshallException("element " + i + " " + e.getMessage(), e); } return m; } public Object unmarshall(SerializerState state, Class clazz, Object o) throws UnmarshallException { JSONObject jso = null; JSONArray jsonlist = null; AbstractList al = new ArrayList(); if (o instanceof JSONObject) { jso = (JSONObject) o; try { jsonlist = jso.getJSONArray("list"); } catch (JSONException e) { throw new UnmarshallException("Could not read list: " + e.getMessage(), e); } } else if (o instanceof JSONArray) { jsonlist = (JSONArray) o; } /*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.List") || java_class.equals("java.util.AbstractList") || java_class.equals("java.util.ArrayList")) { al = new ArrayList(); } else if (java_class.equals("java.util.LinkedList")) { al = new LinkedList(); } else if (java_class.equals("java.util.Vector")) { al = new Vector(); } else { throw new UnmarshallException("not a List"); }*/ if (jsonlist == null) { throw new UnmarshallException("list missing"); } state.setSerialized(o, al); int i = 0; try { for (; i < jsonlist.length(); i++) { al.add(ser.unmarshall(state, null, jsonlist.get(i))); } } catch (UnmarshallException e) { throw new UnmarshallException("element " + i + " " + e.getMessage(), e); } catch (JSONException e) { throw new UnmarshallException("element " + i + " " + e.getMessage(), e); } return al; } }