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XWork is an command-pattern framework that is used to power WebWork
as well as other applications. XWork provides an Inversion of Control
container, a powerful expression language, data type conversion,
validation, and pluggable configuration.
/*
* Copyright (c) 2002-2006 by OpenSymphony
* All rights reserved.
*/
package com.opensymphony.xwork2.util;
import com.opensymphony.xwork2.DefaultTextProvider;
import com.opensymphony.xwork2.XWorkException;
import com.opensymphony.xwork2.inject.Inject;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import ognl.*;
import java.io.Serializable;
import java.util.*;
/**
* Ognl implementation of a value stack that allows for dynamic Ognl expressions to be evaluated against it. When
* evaluating an expression, the stack will be searched down the stack, from the latest objects pushed in to the
* earliest, looking for a bean with a getter or setter for the given property or a method of the given name (depending
* on the expression being evaluated).
*
* @author Patrick Lightbody
* @author tm_jee
*
* @version $Date: 2007-05-18 18:39:01 +0200 (Fr, 18 Mai 2007) $ $Id: OgnlValueStack.java 1508 2007-05-18 16:39:01Z rainerh $
*/
public class OgnlValueStack implements Serializable, ValueStack {
private static final long serialVersionUID = 370737852934925530L;
private static CompoundRootAccessor accessor;
private static Log LOG = LogFactory.getLog(OgnlValueStack.class);
private static boolean devMode;
static {
reset();
}
public static void reset() {
accessor = new CompoundRootAccessor();
OgnlRuntime.setPropertyAccessor(CompoundRoot.class, accessor);
OgnlRuntime.setPropertyAccessor(Object.class, new ObjectAccessor());
OgnlRuntime.setPropertyAccessor(Iterator.class, new XWorkIteratorPropertyAccessor());
OgnlRuntime.setPropertyAccessor(Enumeration.class, new XWorkEnumerationAcccessor());
OgnlRuntime.setPropertyAccessor(List.class, new XWorkListPropertyAccessor());
OgnlRuntime.setPropertyAccessor(Map.class, new XWorkMapPropertyAccessor());
OgnlRuntime.setPropertyAccessor(Collection.class, new XWorkCollectionPropertyAccessor());
OgnlRuntime.setPropertyAccessor(Set.class, new XWorkCollectionPropertyAccessor());
OgnlRuntime.setPropertyAccessor(ObjectProxy.class, new ObjectProxyPropertyAccessor());
OgnlRuntime.setMethodAccessor(Object.class, new XWorkMethodAccessor());
OgnlRuntime.setMethodAccessor(CompoundRoot.class, accessor);
OgnlRuntime.setNullHandler(Object.class, new InstantiatingNullHandler());
}
public static class ObjectAccessor extends ObjectPropertyAccessor {
public Object getProperty(Map map, Object o, Object o1) throws OgnlException {
Object obj = super.getProperty(map, o, o1);
link(map, o.getClass(), (String) o1);
map.put(XWorkConverter.LAST_BEAN_CLASS_ACCESSED, o.getClass());
map.put(XWorkConverter.LAST_BEAN_PROPERTY_ACCESSED, o1.toString());
OgnlContextState.updateCurrentPropertyPath(map, o1);
return obj;
}
public void setProperty(Map map, Object o, Object o1, Object o2) throws OgnlException {
super.setProperty(map, o, o1, o2);
}
}
public static void link(Map context, Class clazz, String name) {
context.put("__link", new Object[]{clazz, name});
}
CompoundRoot root;
transient Map context;
Class defaultType;
Map overrides;
public OgnlValueStack() {
setRoot(new CompoundRoot());
push(DefaultTextProvider.INSTANCE);
}
public OgnlValueStack(ValueStack vs) {
setRoot(new CompoundRoot(vs.getRoot()));
}
public static CompoundRootAccessor getAccessor() {
return accessor;
}
@Inject(value = "devMode", required = false)
public static void setDevMode(String mode) {
devMode = "true".equals(mode);
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#getContext()
*/
public Map getContext() {
return context;
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#setDefaultType(java.lang.Class)
*/
public void setDefaultType(Class defaultType) {
this.defaultType = defaultType;
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#setExprOverrides(java.util.Map)
*/
public void setExprOverrides(Map overrides) {
if (this.overrides == null) {
this.overrides = overrides;
}
else {
this.overrides.putAll(overrides);
}
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#getExprOverrides()
*/
public Map getExprOverrides() {
return this.overrides;
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#getRoot()
*/
public CompoundRoot getRoot() {
return root;
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#setValue(java.lang.String, java.lang.Object)
*/
public void setValue(String expr, Object value) {
setValue(expr, value, devMode);
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#setValue(java.lang.String, java.lang.Object, boolean)
*/
public void setValue(String expr, Object value, boolean throwExceptionOnFailure) {
Map context = getContext();
try {
context.put(XWorkConverter.CONVERSION_PROPERTY_FULLNAME, expr);
context.put(REPORT_ERRORS_ON_NO_PROP, (throwExceptionOnFailure) ? Boolean.TRUE : Boolean.FALSE);
OgnlUtil.setValue(expr, context, root, value);
} catch (OgnlException e) {
if (throwExceptionOnFailure) {
String msg = "Error setting expression '" + expr + "' with value '" + value + "'";
throw new XWorkException(msg, e);
} else {
if (LOG.isDebugEnabled()) {
LOG.debug("Error setting value", e);
}
}
} catch (RuntimeException re) { //XW-281
if (throwExceptionOnFailure) {
String msg = "Error setting expression '" + expr + "' with value '" + value + "'";
throw new XWorkException(msg, re);
} else {
if (LOG.isDebugEnabled()) {
LOG.debug("Error setting value", re);
}
}
} finally {
OgnlContextState.clear(context);
context.remove(XWorkConverter.CONVERSION_PROPERTY_FULLNAME);
context.remove(REPORT_ERRORS_ON_NO_PROP);
}
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#findString(java.lang.String)
*/
public String findString(String expr) {
return (String) findValue(expr, String.class);
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#findValue(java.lang.String)
*/
public Object findValue(String expr) {
try {
if (expr == null) {
return null;
}
if ((overrides != null) && overrides.containsKey(expr)) {
expr = (String) overrides.get(expr);
}
if (defaultType != null) {
return findValue(expr, defaultType);
}
Object value = OgnlUtil.getValue(expr, context, root);
if (value != null) {
return value;
} else {
return findInContext(expr);
}
} catch (OgnlException e) {
return findInContext(expr);
} catch (Exception e) {
logLookupFailure(expr, e);
return findInContext(expr);
} finally {
OgnlContextState.clear(context);
}
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#findValue(java.lang.String, java.lang.Class)
*/
public Object findValue(String expr, Class asType) {
try {
if (expr == null) {
return null;
}
if ((overrides != null) && overrides.containsKey(expr)) {
expr = (String) overrides.get(expr);
}
Object value = OgnlUtil.getValue(expr, context, root, asType);
if (value != null) {
return value;
} else {
return findInContext(expr);
}
} catch (OgnlException e) {
return findInContext(expr);
} catch (Exception e) {
logLookupFailure(expr, e);
return findInContext(expr);
} finally {
OgnlContextState.clear(context);
}
}
private Object findInContext(String name) {
return getContext().get(name);
}
/**
* Log a failed lookup, being more verbose when devMode=true.
*
* @param expr The failed expression
* @param e The thrown exception.
*/
private void logLookupFailure(String expr, Exception e) {
StringBuffer msg = new StringBuffer();
msg.append("Caught an exception while evaluating expression '").append(expr).append("' against value stack");
if (devMode && LOG.isWarnEnabled()) {
LOG.warn(msg, e);
LOG.warn("NOTE: Previous warning message was issued due to devMode set to true.");
} else if (LOG.isDebugEnabled()) {
LOG.debug(msg, e);
}
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#peek()
*/
public Object peek() {
return root.peek();
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#pop()
*/
public Object pop() {
return root.pop();
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#push(java.lang.Object)
*/
public void push(Object o) {
root.push(o);
}
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#set(java.lang.String, java.lang.Object)
*/
public void set(String key, Object o) {
//set basically is backed by a Map
//pushed on the stack with a key
//being put on the map and the
//Object being the value
Map setMap=null;
//check if this is a Map
//put on the stack for setting
//if so just use the old map (reduces waste)
Object topObj=peek();
if (topObj instanceof Map
&&((Map)topObj).get(MAP_IDENTIFIER_KEY)!=null) {
setMap=(Map)topObj;
} else {
setMap=new HashMap();
//the map identifier key ensures
//that this map was put there
//for set purposes and not by a user
//whose data we don't want to touch
setMap.put(MAP_IDENTIFIER_KEY,"");
push(setMap);
}
setMap.put(key,o);
}
private static final String MAP_IDENTIFIER_KEY="com.opensymphony.xwork2.util.OgnlValueStack.MAP_IDENTIFIER_KEY";
/* (non-Javadoc)
* @see com.opensymphony.xwork2.util.ValueStack#size()
*/
public int size() {
return root.size();
}
private void setRoot(CompoundRoot compoundRoot) {
this.root = compoundRoot;
this.context = Ognl.createDefaultContext(this.root, accessor, XWorkConverter.getInstance());
context.put(VALUE_STACK, this);
Ognl.setClassResolver(context, accessor);
((OgnlContext) context).setTraceEvaluations(false);
((OgnlContext) context).setKeepLastEvaluation(false);
}
private Object readResolve() {
OgnlValueStack aStack = new OgnlValueStack();
aStack.setRoot(this.root);
return aStack;
}
}