com.opensymphony.xwork2.ognl
Class OgnlValueStack

java.lang.Object
  com.opensymphony.xwork2.ognl.OgnlValueStack

All Implemented Interfaces:

ValueStack, Serializable

public class OgnlValueStack
extends Object
implements Serializable, ValueStack

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).

Version:

$Date: 2007-10-15 19:04:43 +0200 (Mon, 15 Oct 2007) $ $Id: OgnlValueStack.java 1647 2007-10-15 17:04:43Z rainerh $

Author:

Patrick Lightbody, tm_jee

See Also:

Serialized Form

Field Summary

(package private) Map	context
(package private) Class	defaultType
private boolean	devMode
private static Logger	LOG
private static String	MAP_IDENTIFIER_KEY
(package private) OgnlUtil	ognlUtil
(package private) Map	overrides
(package private) CompoundRoot	root
private static long	serialVersionUID

Fields inherited from interface com.opensymphony.xwork2.util.ValueStack

REPORT_ERRORS_ON_NO_PROP, VALUE_STACK

Constructor Summary

protected	OgnlValueStack(ValueStack vs, XWorkConverter xworkConverter, CompoundRootAccessor accessor, boolean allowStaticAccess)
protected	OgnlValueStack(XWorkConverter xworkConverter, CompoundRootAccessor accessor, TextProvider prov, boolean allowStaticAccess)

Method Summary

private void	checkForInvalidProperties(String expr) This method looks for matching methods/properties in an action to warn the user if they specified a property that doesn't exist.
private void	findAvailableProperties(Class c, String expr, Set availableProperties, String parent) Look for available properties on an existing class.
private Object	findInContext(String name)
String	findString(String expr)
Object	findValue(String expr) Find a value by evaluating the given expression against the stack in the default search order.
Object	findValue(String expr, Class asType) Find a value by evaluating the given expression against the stack in the default search order.
Map	getContext() Gets the context for this value stack.
Map	getExprOverrides() Gets the override map if anyone exists.
CompoundRoot	getRoot() Get the CompoundRoot which holds the objects pushed onto the stack
static void	link(Map context, Class clazz, String name)
private void	logLookupFailure(String expr, Exception e) Log a failed lookup, being more verbose when devMode=true.
Object	peek() Get the object on the top of the stack without changing the stack.
Object	pop() Get the object on the top of the stack and remove it from the stack.
void	push(Object o) Put this object onto the top of the stack
private Object	readResolve()
void	set(String key, Object o) Sets an object on the stack with the given key so it is retrievable by ValueStack.findValue(String), ValueStack.findValue(String, Class)
void	setDefaultType(Class defaultType) Sets the default type to convert to if no type is provided when getting a value.
void	setDevMode(String mode)
void	setExprOverrides(Map overrides) Set a override map containing key -> values that takes precedent when doing find operations on the ValueStack.
void	setOgnlUtil(OgnlUtil ognlUtil)
protected void	setRoot(XWorkConverter xworkConverter, CompoundRootAccessor accessor, CompoundRoot compoundRoot, boolean allowStaticMethodAccess)
void	setValue(String expr, Object value) Attempts to set a property on a bean in the stack with the given expression using the default search order.
void	setValue(String expr, Object value, boolean throwExceptionOnFailure) Attempts to set a property on a bean in the stack with the given expression using the default search order.
int	size() Get the number of objects in the stack

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

LOG

private static Logger LOG

devMode

private boolean devMode

root

CompoundRoot root

context

transient Map context

defaultType

Class defaultType

overrides

Map overrides

ognlUtil

transient OgnlUtil ognlUtil

MAP_IDENTIFIER_KEY

private static final String MAP_IDENTIFIER_KEY

See Also:

Constant Field Values

Constructor Detail

OgnlValueStack

protected OgnlValueStack(XWorkConverter xworkConverter,
                         CompoundRootAccessor accessor,
                         TextProvider prov,
                         boolean allowStaticAccess)

OgnlValueStack

protected OgnlValueStack(ValueStack vs,
                         XWorkConverter xworkConverter,
                         CompoundRootAccessor accessor,
                         boolean allowStaticAccess)

Method Detail

link

public static void link(Map context,
                        Class clazz,
                        String name)

setOgnlUtil

public void setOgnlUtil(OgnlUtil ognlUtil)

setRoot

protected void setRoot(XWorkConverter xworkConverter,
                       CompoundRootAccessor accessor,
                       CompoundRoot compoundRoot,
                       boolean allowStaticMethodAccess)

setDevMode

public void setDevMode(String mode)

getContext

public Map getContext()

Description copied from interface: ValueStack

Gets the context for this value stack. The context holds all the information in the value stack and it's surroundings.

Specified by:

getContext in interface ValueStack

Returns:

the context.

setDefaultType

public void setDefaultType(Class defaultType)

Description copied from interface: ValueStack

Sets the default type to convert to if no type is provided when getting a value.

Specified by:

setDefaultType in interface ValueStack

Parameters:

defaultType - the new default type

setExprOverrides

public void setExprOverrides(Map overrides)

Description copied from interface: ValueStack

Set a override map containing key -> values that takes precedent when doing find operations on the ValueStack.

See the unit test for ValueStackTest for examples.

Specified by:

setExprOverrides in interface ValueStack

Parameters:

overrides - overrides map.

getExprOverrides

public Map getExprOverrides()

Description copied from interface: ValueStack

Gets the override map if anyone exists.

Specified by:

getExprOverrides in interface ValueStack

Returns:

the override map, null if not set.

getRoot

public CompoundRoot getRoot()

Description copied from interface: ValueStack

Get the CompoundRoot which holds the objects pushed onto the stack

Specified by:

getRoot in interface ValueStack

Returns:

the root

setValue

public void setValue(String expr,
                     Object value)

Description copied from interface: ValueStack

Attempts to set a property on a bean in the stack with the given expression using the default search order.

Specified by:

setValue in interface ValueStack

Parameters:

expr - the expression defining the path to the property to be set.

value - the value to be set into the named property

setValue

public void setValue(String expr,
                     Object value,
                     boolean throwExceptionOnFailure)

Description copied from interface: ValueStack

Attempts to set a property on a bean in the stack with the given expression using the default search order.

Specified by:

setValue in interface ValueStack

Parameters:

expr - the expression defining the path to the property to be set.

value - the value to be set into the named property

throwExceptionOnFailure - a flag to tell whether an exception should be thrown if there is no property with the given name.

findString

public String findString(String expr)

Specified by:

findString in interface ValueStack

findValue

public Object findValue(String expr)

Description copied from interface: ValueStack

Find a value by evaluating the given expression against the stack in the default search order.

Specified by:

findValue in interface ValueStack

Parameters:

expr - the expression giving the path of properties to navigate to find the property value to return

Returns:

the result of evaluating the expression

findValue

public Object findValue(String expr,
                        Class asType)

Description copied from interface: ValueStack

Find a value by evaluating the given expression against the stack in the default search order.

Specified by:

findValue in interface ValueStack

Parameters:

expr - the expression giving the path of properties to navigate to find the property value to return

asType - the type to convert the return value to

Returns:

the result of evaluating the expression

findInContext

private Object findInContext(String name)

checkForInvalidProperties

private void checkForInvalidProperties(String expr)

This method looks for matching methods/properties in an action to warn the user if they specified a property that doesn't exist.

Parameters:

expr - the property expression

findAvailableProperties

private void findAvailableProperties(Class c,
                                     String expr,
                                     Set availableProperties,
                                     String parent)
                              throws IntrospectionException

Look for available properties on an existing class.

Parameters:

c - the class to search on

expr - the property expression

availableProperties - a set of properties found

parent - a parent property

Throws:

IntrospectionException - when Ognl can't get property descriptors

logLookupFailure

private void logLookupFailure(String expr,
                              Exception e)

Log a failed lookup, being more verbose when devMode=true.

Parameters:

expr - The failed expression

e - The thrown exception.

peek

public Object peek()

Description copied from interface: ValueStack

Get the object on the top of the stack without changing the stack.

Specified by:

peek in interface ValueStack

Returns:

the object on the top.

See Also:

CompoundRoot.peek()

pop

public Object pop()

Description copied from interface: ValueStack

Get the object on the top of the stack and remove it from the stack.

Specified by:

pop in interface ValueStack

Returns:

the object on the top of the stack

See Also:

CompoundRoot.pop()

push

public void push(Object o)

Description copied from interface: ValueStack

Put this object onto the top of the stack

Specified by:

push in interface ValueStack

Parameters:

o - the object to be pushed onto the stack

See Also:

CompoundRoot.push(Object)

set

public void set(String key,
                Object o)

Description copied from interface: ValueStack

Sets an object on the stack with the given key so it is retrievable by ValueStack.findValue(String), ValueStack.findValue(String, Class)

Specified by:

set in interface ValueStack

Parameters:

key - the key

o - the object

size

public int size()

Description copied from interface: ValueStack

Get the number of objects in the stack

Specified by:

size in interface ValueStack

Returns:

the number of objects in the stack

readResolve

private Object readResolve()