org.apache.tomcat.util.digester

Class CallMethodRule

public class CallMethodRule extends Rule

Rule implementation that calls a method on an object on the stack (normally the top/parent object), passing arguments collected from subsequent CallParamRule rules or from the body of this element.

By using CallMethodRule a method call can be made to a method which accepts no arguments.

Incompatible method parameter types are converted using org.apache.commons.beanutils.ConvertUtils.

This rule now uses org.apache.commons.beanutils.MethodUtils#invokeMethod by default. This increases the kinds of methods successfully and allows primitives to be matched by passing in wrapper classes. There are rare cases when org.apache.commons.beanutils.MethodUtils#invokeExactMethod (the old default) is required. This method is much stricter in its reflection. Setting the UseExactMatch to true reverts to the use of this method.

Note that the target method is invoked when the end of the tag the CallMethodRule fired on is encountered, not when the last parameter becomes available. This implies that rules which fire on tags nested within the one associated with the CallMethodRule will fire before the CallMethodRule invokes the target method. This behaviour is not configurable.

Note also that if a CallMethodRule is expecting exactly one parameter and that parameter is not available (eg CallParamRule is used with an attribute name but the attribute does not exist) then the method will not be invoked. If a CallMethodRule is expecting more than one parameter, then it is always invoked, regardless of whether the parameters were available or not (missing parameters are passed as null values).

Field Summary
protected StringbodyText
The body text collected from this element.
protected StringmethodName
The method name to call on the parent object.
protected String[]paramClassNames
The names of the classes of the parameters to be collected.
protected intparamCount
The number of parameters to collect from MethodParam rules.
protected Class[]paramTypes
The parameter types of the parameters to be collected.
protected inttargetOffset
location of the target object for the call, relative to the top of the digester object stack.
protected booleanuseExactMatch
Should MethodUtils.invokeExactMethod be used for reflection.
Constructor Summary
CallMethodRule(Digester digester, String methodName, int paramCount)
Construct a "call method" rule with the specified method name.
CallMethodRule(Digester digester, String methodName, int paramCount, String[] paramTypes)
Construct a "call method" rule with the specified method name.
CallMethodRule(Digester digester, String methodName, int paramCount, Class[] paramTypes)
Construct a "call method" rule with the specified method name.
CallMethodRule(String methodName, int paramCount)
Construct a "call method" rule with the specified method name.
CallMethodRule(int targetOffset, String methodName, int paramCount)
Construct a "call method" rule with the specified method name.
CallMethodRule(String methodName)
Construct a "call method" rule with the specified method name.
CallMethodRule(int targetOffset, String methodName)
Construct a "call method" rule with the specified method name.
CallMethodRule(String methodName, int paramCount, String[] paramTypes)
Construct a "call method" rule with the specified method name and parameter types.
CallMethodRule(int targetOffset, String methodName, int paramCount, String[] paramTypes)
Construct a "call method" rule with the specified method name and parameter types.
CallMethodRule(String methodName, int paramCount, Class[] paramTypes)
Construct a "call method" rule with the specified method name and parameter types.
CallMethodRule(int targetOffset, String methodName, int paramCount, Class[] paramTypes)
Construct a "call method" rule with the specified method name and parameter types.
Method Summary
voidbegin(Attributes attributes)
Process the start of this element.
voidbody(String bodyText)
Process the body text of this element.
voidend()
Process the end of this element.
voidfinish()
Clean up after parsing is complete.
booleangetUseExactMatch()
Should MethodUtils.invokeExactMethod be used for the reflection.
protected voidprocessMethodCallResult(Object result)
Subclasses may override this method to perform additional processing of the invoked method's result.
voidsetDigester(Digester digester)
Set the associated digester.
voidsetUseExactMatch(boolean useExactMatch)
Set whether MethodUtils.invokeExactMethod should be used for the reflection.
StringtoString()
Render a printable version of this Rule.

Field Detail

bodyText

protected String bodyText
The body text collected from this element.

methodName

protected String methodName
The method name to call on the parent object.

paramClassNames

protected String[] paramClassNames
The names of the classes of the parameters to be collected. This attribute allows creation of the classes to be postponed until the digester is set.

paramCount

protected int paramCount
The number of parameters to collect from MethodParam rules. If this value is zero, a single parameter will be collected from the body of this element.

paramTypes

protected Class[] paramTypes
The parameter types of the parameters to be collected.

targetOffset

protected int targetOffset
location of the target object for the call, relative to the top of the digester object stack. The default value of zero means the target object is the one on top of the stack.

useExactMatch

protected boolean useExactMatch
Should MethodUtils.invokeExactMethod be used for reflection.

Constructor Detail

CallMethodRule

public CallMethodRule(Digester digester, String methodName, int paramCount)

Deprecated: The digester instance is now set in the Digester method. Use CallMethodRule instead.

Construct a "call method" rule with the specified method name. The parameter types (if any) default to java.lang.String.

Parameters: digester The associated Digester methodName Method name of the parent method to call paramCount The number of parameters to collect, or zero for a single argument from the body of this element.

CallMethodRule

public CallMethodRule(Digester digester, String methodName, int paramCount, String[] paramTypes)

Deprecated: The digester instance is now set in the Digester method. Use (String methodName,int paramCount, String [] paramTypes) instead.

Construct a "call method" rule with the specified method name.

Parameters: digester The associated Digester methodName Method name of the parent method to call paramCount The number of parameters to collect, or zero for a single argument from the body of ths element paramTypes The Java class names of the arguments (if you wish to use a primitive type, specify the corresonding Java wrapper class instead, such as java.lang.Boolean for a boolean parameter)

CallMethodRule

public CallMethodRule(Digester digester, String methodName, int paramCount, Class[] paramTypes)

Deprecated: The digester instance is now set in the Digester method. Use (String methodName,int paramCount, Class [] paramTypes) instead.

Construct a "call method" rule with the specified method name.

Parameters: digester The associated Digester methodName Method name of the parent method to call paramCount The number of parameters to collect, or zero for a single argument from the body of ths element paramTypes The Java classes that represent the parameter types of the method arguments (if you wish to use a primitive type, specify the corresonding Java wrapper class instead, such as java.lang.Boolean.TYPE for a boolean parameter)

CallMethodRule

public CallMethodRule(String methodName, int paramCount)
Construct a "call method" rule with the specified method name. The parameter types (if any) default to java.lang.String.

Parameters: methodName Method name of the parent method to call paramCount The number of parameters to collect, or zero for a single argument from the body of this element.

CallMethodRule

public CallMethodRule(int targetOffset, String methodName, int paramCount)
Construct a "call method" rule with the specified method name. The parameter types (if any) default to java.lang.String.

Parameters: targetOffset location of the target object. Positive numbers are relative to the top of the digester object stack. Negative numbers are relative to the bottom of the stack. Zero implies the top object on the stack. methodName Method name of the parent method to call paramCount The number of parameters to collect, or zero for a single argument from the body of this element.

CallMethodRule

public CallMethodRule(String methodName)
Construct a "call method" rule with the specified method name. The method should accept no parameters.

Parameters: methodName Method name of the parent method to call

CallMethodRule

public CallMethodRule(int targetOffset, String methodName)
Construct a "call method" rule with the specified method name. The method should accept no parameters.

Parameters: targetOffset location of the target object. Positive numbers are relative to the top of the digester object stack. Negative numbers are relative to the bottom of the stack. Zero implies the top object on the stack. methodName Method name of the parent method to call

CallMethodRule

public CallMethodRule(String methodName, int paramCount, String[] paramTypes)
Construct a "call method" rule with the specified method name and parameter types. If paramCount is set to zero the rule will use the body of this element as the single argument of the method, unless paramTypes is null or empty, in this case the rule will call the specified method with no arguments.

Parameters: methodName Method name of the parent method to call paramCount The number of parameters to collect, or zero for a single argument from the body of ths element paramTypes The Java class names of the arguments (if you wish to use a primitive type, specify the corresonding Java wrapper class instead, such as java.lang.Boolean for a boolean parameter)

CallMethodRule

public CallMethodRule(int targetOffset, String methodName, int paramCount, String[] paramTypes)
Construct a "call method" rule with the specified method name and parameter types. If paramCount is set to zero the rule will use the body of this element as the single argument of the method, unless paramTypes is null or empty, in this case the rule will call the specified method with no arguments.

Parameters: targetOffset location of the target object. Positive numbers are relative to the top of the digester object stack. Negative numbers are relative to the bottom of the stack. Zero implies the top object on the stack. methodName Method name of the parent method to call paramCount The number of parameters to collect, or zero for a single argument from the body of ths element paramTypes The Java class names of the arguments (if you wish to use a primitive type, specify the corresonding Java wrapper class instead, such as java.lang.Boolean for a boolean parameter)

CallMethodRule

public CallMethodRule(String methodName, int paramCount, Class[] paramTypes)
Construct a "call method" rule with the specified method name and parameter types. If paramCount is set to zero the rule will use the body of this element as the single argument of the method, unless paramTypes is null or empty, in this case the rule will call the specified method with no arguments.

Parameters: methodName Method name of the parent method to call paramCount The number of parameters to collect, or zero for a single argument from the body of ths element paramTypes The Java classes that represent the parameter types of the method arguments (if you wish to use a primitive type, specify the corresonding Java wrapper class instead, such as java.lang.Boolean.TYPE for a boolean parameter)

CallMethodRule

public CallMethodRule(int targetOffset, String methodName, int paramCount, Class[] paramTypes)
Construct a "call method" rule with the specified method name and parameter types. If paramCount is set to zero the rule will use the body of this element as the single argument of the method, unless paramTypes is null or empty, in this case the rule will call the specified method with no arguments.

Parameters: targetOffset location of the target object. Positive numbers are relative to the top of the digester object stack. Negative numbers are relative to the bottom of the stack. Zero implies the top object on the stack. methodName Method name of the parent method to call paramCount The number of parameters to collect, or zero for a single argument from the body of ths element paramTypes The Java classes that represent the parameter types of the method arguments (if you wish to use a primitive type, specify the corresonding Java wrapper class instead, such as java.lang.Boolean.TYPE for a boolean parameter)

Method Detail

begin

public void begin(Attributes attributes)
Process the start of this element.

Parameters: attributes The attribute list for this element

body

public void body(String bodyText)
Process the body text of this element.

Parameters: bodyText The body text of this element

end

public void end()
Process the end of this element.

finish

public void finish()
Clean up after parsing is complete.

getUseExactMatch

public boolean getUseExactMatch()
Should MethodUtils.invokeExactMethod be used for the reflection.

processMethodCallResult

protected void processMethodCallResult(Object result)
Subclasses may override this method to perform additional processing of the invoked method's result.

Parameters: result the Object returned by the method invoked, possibly null

setDigester

public void setDigester(Digester digester)
Set the associated digester. If needed, this class loads the parameter classes from their names.

setUseExactMatch

public void setUseExactMatch(boolean useExactMatch)
Set whether MethodUtils.invokeExactMethod should be used for the reflection.

toString

public String toString()
Render a printable version of this Rule.
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