com.metaparadigm.jsonrpc.BeanSerializer Maven / Gradle / Ivy
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/*
* JSON-RPC-Java - a JSON-RPC to Java Bridge with dynamic invocation
*
* $Id: BeanSerializer.java,v 1.7.2.2 2006/03/06 12:39:21 mclark Exp $
*
* Copyright Metaparadigm Pte. Ltd. 2004.
* Michael Clark
*
* 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 com.metaparadigm.jsonrpc;
import java.util.Map;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.logging.Logger;
import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;
import java.beans.Introspector;
import java.beans.IntrospectionException;
import java.beans.PropertyDescriptor;
import java.beans.BeanInfo;
import org.json.JSONObject;
public class BeanSerializer extends AbstractSerializer
{
private final static long serialVersionUID = 1;
private final static Logger log =
Logger.getLogger(BeanSerializer.class.getName());
private static HashMap beanCache = new HashMap();
private static Class[] _serializableClasses = new Class[] { };
private static Class[] _JSONClasses = new Class[] { };
public Class[] getSerializableClasses() { return _serializableClasses; }
public Class[] getJSONClasses() { return _JSONClasses; }
public boolean canSerialize(Class clazz, Class jsonClazz)
{
return (!clazz.isArray() &&
!clazz.isPrimitive() &&
!clazz.isInterface() &&
(jsonClazz == null || jsonClazz == JSONObject.class));
}
protected static class BeanData
{
//in absence of getters and setters, these fields are
//public to allow subclasses to access.
public BeanInfo beanInfo;
public HashMap readableProps;
public HashMap writableProps;
}
protected static class BeanSerializerState
{
//in absence of getters and setters, these fields are
//public to allow subclasses to access.
// Circular reference detection
public HashSet beanSet = new HashSet();
}
public static BeanData analyzeBean(Class clazz)
throws IntrospectionException
{
log.info("analyzing " + clazz.getName());
BeanData bd = new BeanData();
bd.beanInfo = Introspector.getBeanInfo(clazz, Object.class);
PropertyDescriptor props[] = bd.beanInfo.getPropertyDescriptors();
bd.readableProps = new HashMap();
bd.writableProps = new HashMap();
for(int i=0; i < props.length; i++) {
if(props[i].getWriteMethod() != null) {
bd.writableProps.put(props[i].getName(),
props[i].getWriteMethod());
}
if(props[i].getReadMethod() != null) {
bd.readableProps.put(props[i].getName(),
props[i].getReadMethod());
}
}
return bd;
}
public static BeanData getBeanData(Class clazz)
throws IntrospectionException
{
BeanData bd;
synchronized (beanCache) {
bd = (BeanData)beanCache.get(clazz);
if(bd == null) {
bd = analyzeBean(clazz);
beanCache.put(clazz, bd);
}
}
return bd;
}
public ObjectMatch tryUnmarshall(SerializerState state,
Class clazz, Object o)
throws UnmarshallException
{
JSONObject jso = (JSONObject)o;
BeanData bd = null;
try {
bd = getBeanData(clazz);
} catch (IntrospectionException e) {
throw new UnmarshallException(clazz.getName() + " is not a bean");
}
int match = 0, mismatch = 0;
Iterator i = bd.writableProps.entrySet().iterator();
while(i.hasNext()) {
Map.Entry ent = (Map.Entry)i.next();
String prop = (String)ent.getKey();
Method method = (Method)ent.getValue();
if(jso.has(prop)) match++;
else mismatch++;
}
if(match == 0) throw new UnmarshallException("bean has no matches");
ObjectMatch m = null, tmp = null;
i = jso.keys();
while(i.hasNext()) {
String field = (String)i.next();
Method setMethod = (Method)bd.writableProps.get(field);
if(setMethod != null) {
try {
Class param[] = setMethod.getParameterTypes();
if(param.length != 1)
throw new UnmarshallException
("bean " + clazz.getName() +
" method " + setMethod.getName() +
" does not have one arg");
tmp = ser.tryUnmarshall(state, param[0], jso.get(field));
if(m == null) m = tmp;
else m = m.max(tmp);
} catch (UnmarshallException e) {
throw new UnmarshallException("bean " + clazz.getName() +
" " + e.getMessage());
}
} else {
mismatch++;
}
}
return m.max(new ObjectMatch(mismatch));
}
public Object unmarshall(SerializerState state, Class clazz, Object o)
throws UnmarshallException
{
JSONObject jso = (JSONObject)o;
BeanData bd = null;
try {
bd = getBeanData(clazz);
} catch (IntrospectionException e) {
throw new UnmarshallException(clazz.getName() + " is not a bean");
}
if(ser.isDebug())
log.fine("instantiating " + clazz.getName());
Object instance = null;
try {
instance = clazz.newInstance();
} catch (Exception e) {
throw new UnmarshallException
("can't instantiate bean " +
clazz.getName() + ": " + e.getMessage());
}
Object invokeArgs[] = new Object[1];
Object fieldVal;
Iterator i = jso.keys();
while(i.hasNext()) {
String field = (String)i.next();
Method setMethod = (Method)bd.writableProps.get(field);
if(setMethod != null) {
try {
Class param[] = setMethod.getParameterTypes();
fieldVal = ser.unmarshall(state, param[0], jso.get(field));
} catch (UnmarshallException e) {
throw new UnmarshallException("bean " + clazz.getName() +
" " + e.getMessage());
}
if(ser.isDebug())
log.fine("invoking " + setMethod.getName() +
"(" + fieldVal + ")");
invokeArgs[0] = fieldVal;
try {
setMethod.invoke(instance, invokeArgs);
} catch (Throwable e) {
if(e instanceof InvocationTargetException)
e = ((InvocationTargetException)e).
getTargetException();
throw new UnmarshallException
("bean " + clazz.getName() + "can't invoke " +
setMethod.getName() + ": " + e.getMessage());
}
}
}
return instance;
}
public Object marshall(SerializerState state, Object o)
throws MarshallException
{
BeanSerializerState beanState;
try {
beanState = (BeanSerializerState)
state.get(BeanSerializerState.class);
} catch (Exception e) {
throw new MarshallException("bean serializer internal error");
}
Integer identity = new Integer(System.identityHashCode (o));
if(beanState.beanSet.contains(identity))
throw new MarshallException("circular reference");
beanState.beanSet.add(identity);
BeanData bd = null;
try {
bd = getBeanData(o.getClass());
} catch (IntrospectionException e) {
throw new MarshallException
(o.getClass().getName() + " is not a bean");
}
JSONObject val = new JSONObject();
if (ser.getMarshallClassHints())
val.put("javaClass", o.getClass().getName());
Iterator i = bd.readableProps.entrySet().iterator();
Object args[] = new Object[0];
Object result = null;
while(i.hasNext()) {
Map.Entry ent = (Map.Entry)i.next();
String prop = (String)ent.getKey();
Method getMethod = (Method)ent.getValue();
if(ser.isDebug())
log.fine("invoking " + getMethod.getName() + "()");
try {
result = getMethod.invoke(o, args);
} catch (Throwable e) {
if(e instanceof InvocationTargetException)
e = ((InvocationTargetException)e).
getTargetException();
throw new MarshallException
("bean " + o.getClass().getName() + " can't invoke " +
getMethod.getName() + ": " + e.getMessage());
}
try {
if (result != null || ser.getMarshallNullAttributes())
val.put(prop, ser.marshall(state, result));
} catch (MarshallException e) {
throw new MarshallException
("bean " + o.getClass().getName() + " " + e.getMessage());
}
}
beanState.beanSet.remove(identity);
return val;
}
}
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