/*
* Copyright 2002,2004 The Apache Software Foundation.
*
* 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.apache.commons.jexl.util.introspection;
import org.apache.commons.jexl.util.ArrayIterator;
import org.apache.commons.jexl.util.EnumerationIterator;
import org.apache.commons.jexl.util.AbstractExecutor;
import org.apache.commons.jexl.util.GetExecutor;
import org.apache.commons.jexl.util.BooleanPropertyExecutor;
import org.apache.commons.jexl.util.PropertyExecutor;
import org.apache.commons.logging.Log;
import java.lang.reflect.Method;
import java.lang.reflect.InvocationTargetException;
import java.util.Iterator;
import java.util.Collection;
import java.util.Map;
import java.util.Enumeration;
import java.util.ArrayList;
/**
* Implementation of Uberspect to provide the default introspective
* functionality of Velocity.
*
* @since 1.0
* @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
* @version $Id: UberspectImpl.java 398509 2006-05-01 03:34:35Z dion $
*/
public class UberspectImpl implements Uberspect, UberspectLoggable {
/** index of the first character of the property. */
private static final int PROPERTY_START_INDEX = 3;
/**
* Our runtime logger.
*/
private Log rlog;
/**
* the default Velocity introspector.
*/
private static Introspector introspector;
/**
* init - does nothing - we need to have setRuntimeLogger called before
* getting our introspector, as the default vel introspector depends upon
* it.
* @throws Exception on any error.
*/
public void init() throws Exception {
}
/**
* Sets the runtime logger - this must be called before anything else
* besides init() as to get the logger. Makes the pull model appealing...
* @param runtimeLogger service to use for logging.
*/
public void setRuntimeLogger(Log runtimeLogger) {
rlog = runtimeLogger;
introspector = new Introspector(rlog);
}
/**
* {@inheritDoc}
*/
public Iterator getIterator(Object obj, Info i) throws Exception {
if (obj.getClass().isArray()) {
return new ArrayIterator(obj);
} else if (obj instanceof Collection) {
return ((Collection) obj).iterator();
} else if (obj instanceof Map) {
return ((Map) obj).values().iterator();
} else if (obj instanceof Iterator) {
rlog.warn("Warning! The iterative " + " is an Iterator in the #foreach() loop at [" + i.getLine() + ","
+ i.getColumn() + "]" + " in template " + i.getTemplateName() + ". Because it's not resetable,"
+ " if used in more than once, this may lead to" + " unexpected results.");
return ((Iterator) obj);
} else if (obj instanceof Enumeration) {
rlog.warn("Warning! The iterative " + " is an Enumeration in the #foreach() loop at [" + i.getLine() + ","
+ i.getColumn() + "]" + " in template " + i.getTemplateName() + ". Because it's not resetable,"
+ " if used in more than once, this may lead to" + " unexpected results.");
return new EnumerationIterator((Enumeration) obj);
}
/* we have no clue what this is */
rlog.warn("Could not determine type of iterator in " + "#foreach loop " + " at [" + i.getLine() + ","
+ i.getColumn() + "]" + " in template " + i.getTemplateName());
return null;
}
/**
* {@inheritDoc}
*/
public VelMethod getMethod(Object obj, String methodName, Object[] args, Info i) throws Exception {
if (obj == null) {
return null;
}
Method m = introspector.getMethod(obj.getClass(), methodName, args);
if (m == null && obj instanceof Class) {
m = introspector.getMethod((Class) obj, methodName, args);
}
return (m == null) ? null : new VelMethodImpl(m);
}
/**
* {@inheritDoc}
*/
public VelPropertyGet getPropertyGet(Object obj, String identifier, Info i) throws Exception {
AbstractExecutor executor;
Class claz = obj.getClass();
/*
* first try for a getFoo() type of property (also getfoo() )
*/
executor = new PropertyExecutor(rlog, introspector, claz, identifier);
/*
* look for boolean isFoo()
*/
if (!executor.isAlive()) {
executor = new BooleanPropertyExecutor(rlog, introspector, claz, identifier);
}
/*
* if that didn't work, look for get("foo")
*/
if (!executor.isAlive()) {
executor = new GetExecutor(rlog, introspector, claz, identifier);
}
return (executor == null) ? null : new VelGetterImpl(executor);
}
/**
* {@inheritDoc}
*/
public VelPropertySet getPropertySet(Object obj, String identifier, Object arg, Info i) throws Exception {
Class claz = obj.getClass();
VelMethod vm = null;
try {
/*
* first, we introspect for the set<identifier> setter method
*/
Object[] params = {arg};
try {
vm = getMethod(obj, "set" + identifier, params, i);
if (vm == null) {
throw new NoSuchMethodException();
}
} catch (NoSuchMethodException nsme2) {
StringBuffer sb = new StringBuffer("set");
sb.append(identifier);
if (Character.isLowerCase(sb.charAt(PROPERTY_START_INDEX))) {
sb.setCharAt(PROPERTY_START_INDEX, Character.toUpperCase(sb.charAt(PROPERTY_START_INDEX)));
} else {
sb.setCharAt(PROPERTY_START_INDEX, Character.toLowerCase(sb.charAt(PROPERTY_START_INDEX)));
}
vm = getMethod(obj, sb.toString(), params, i);
if (vm == null) {
throw new NoSuchMethodException();
}
}
} catch (NoSuchMethodException nsme) {
/*
* right now, we only support the Map interface
*/
if (Map.class.isAssignableFrom(claz)) {
Object[] params = {new Object(), new Object()};
vm = getMethod(obj, "put", params, i);
if (vm != null) {
return new VelSetterImpl(vm, identifier);
}
}
}
return (vm == null) ? null : new VelSetterImpl(vm);
}
/**
* An implementation of {@link VelMethod}.
*/
public class VelMethodImpl implements VelMethod {
/** the method. */
protected Method method = null;
/**
* Create a new instance.
*
* @param m the method.
*/
public VelMethodImpl(Method m) {
method = m;
}
/**
* {@inheritDoc}
*/
public Object invoke(Object o, Object[] params) throws Exception {
try {
return method.invoke(o, params);
} catch (InvocationTargetException e) {
final Throwable t = e.getTargetException();
if (t instanceof Exception) {
throw (Exception) t;
} else if (t instanceof Error) {
throw (Error) t;
} else {
throw e;
}
}
}
/**
* {@inheritDoc}
*/
public boolean isCacheable() {
return true;
}
/**
* {@inheritDoc}
*/
public String getMethodName() {
return method.getName();
}
/**
* {@inheritDoc}
*/
public Class getReturnType() {
return method.getReturnType();
}
}
/**
* {@inheritDoc}
*/
public class VelGetterImpl implements VelPropertyGet {
/** executor for performing the get. */
protected AbstractExecutor ae = null;
/**
* Create the getter using an {@link AbstractExecutor} to
* do the work.
* @param exec the executor.
*/
public VelGetterImpl(AbstractExecutor exec) {
ae = exec;
}
/**
* {@inheritDoc}
*/
public Object invoke(Object o) throws Exception {
return ae.execute(o);
}
/**
* {@inheritDoc}
*/
public boolean isCacheable() {
return true;
}
/**
* {@inheritDoc}
*/
public String getMethodName() {
return ae.getMethod().getName();
}
}
/**
* {@inheritDoc}
*/
public class VelSetterImpl implements VelPropertySet {
/** the method to call. */
protected VelMethod vm = null;
/** the key for indexed and other properties. */
protected String putKey = null;
/**
* Create an instance.
* @param velmethod the method to call on set.
*/
public VelSetterImpl(VelMethod velmethod) {
this.vm = velmethod;
}
/**
* Create an instance.
* @param velmethod the method to call on set.
* @param key the index or other value passed to a
* setProperty(xxx, value) method.
*/
public VelSetterImpl(VelMethod velmethod, String key) {
this.vm = velmethod;
putKey = key;
}
/** {@inheritDoc} */
public Object invoke(Object o, Object value) throws Exception {
ArrayList al = new ArrayList();
if (putKey == null) {
al.add(value);
} else {
al.add(putKey);
al.add(value);
}
return vm.invoke(o, al.toArray());
}
/** {@inheritDoc} */
public boolean isCacheable() {
return true;
}
/** {@inheritDoc} */
public String getMethodName() {
return vm.getMethodName();
}
}
}