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(String methodName)
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).
Modifier and Type | Field and Description |
---|---|
protected String |
bodyText
The body text collected from this element.
|
protected String |
methodName
The method name to call on the parent object.
|
protected String[] |
paramClassNames
The names of the classes of the parameters to be collected.
|
protected int |
paramCount
The number of parameters to collect from
MethodParam rules. |
protected Class<?>[] |
paramTypes
The parameter types of the parameters to be collected.
|
protected int |
targetOffset
location of the target object for the call, relative to the
top of the digester object stack.
|
protected boolean |
useExactMatch
Should
MethodUtils.invokeExactMethod be used for reflection. |
digester, namespaceURI
Constructor and Description |
---|
CallMethodRule(int targetOffset,
String methodName,
int paramCount)
Construct a "call method" rule with the specified method name.
|
CallMethodRule(int targetOffset,
String methodName,
int paramCount,
Class<?>[] paramTypes)
Construct a "call method" rule with the specified method name and
parameter types.
|
CallMethodRule(String methodName)
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.
|
Modifier and Type | Method and Description |
---|---|
void |
begin(String namespace,
String name,
Attributes attributes)
Process the start of this element.
|
void |
body(String namespace,
String name,
String bodyText)
Process the body text of this element.
|
void |
end(String namespace,
String name)
Process the end of this element.
|
void |
finish()
Clean up after parsing is complete.
|
boolean |
getUseExactMatch()
Should
MethodUtils.invokeExactMethod
be used for the reflection. |
protected void |
processMethodCallResult(Object result)
Subclasses may override this method to perform additional processing of the
invoked method's result.
|
void |
setDigester(Digester digester)
Set the associated digester.
|
void |
setUseExactMatch(boolean useExactMatch)
Set whether
MethodUtils.invokeExactMethod
should be used for the reflection. |
String |
toString()
Render a printable version of this Rule.
|
begin, body, end, getDigester, getNamespaceURI, setNamespaceURI
protected String bodyText
protected final int targetOffset
protected final String methodName
protected final int paramCount
MethodParam
rules.
If this value is zero, a single parameter will be collected from the
body of this element.protected Class<?>[] paramTypes
protected final String[] paramClassNames
protected boolean useExactMatch
MethodUtils.invokeExactMethod
be used for reflection.public CallMethodRule(String methodName, int paramCount)
methodName
- Method name of the parent method to callparamCount
- The number of parameters to collect, or
zero for a single argument from the body of this element.public CallMethodRule(int targetOffset, String methodName, int paramCount)
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 callparamCount
- The number of parameters to collect, or
zero for a single argument from the body of this element.public CallMethodRule(String methodName)
methodName
- Method name of the parent method to callpublic CallMethodRule(int targetOffset, String methodName, int paramCount, Class<?>[] paramTypes)
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.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 callparamCount
- The number of parameters to collect, or
zero for a single argument from the body of this elementparamTypes
- The Java classes that represent the
parameter types of the method arguments
(if you wish to use a primitive type, specify the corresponding
Java wrapper class instead, such as java.lang.Boolean.TYPE
for a boolean
parameter)public boolean getUseExactMatch()
MethodUtils.invokeExactMethod
be used for the reflection.public void setUseExactMatch(boolean useExactMatch)
MethodUtils.invokeExactMethod
should be used for the reflection.public void setDigester(Digester digester)
setDigester
in class Rule
public void begin(String namespace, String name, Attributes attributes) throws Exception
begin
in class Rule
namespace
- the namespace URI of the matching element, or an
empty string if the parser is not namespace aware or the element has
no namespacename
- the local name if the parser is namespace aware, or just
the element name otherwiseattributes
- The attribute list for this elementException
public void body(String namespace, String name, String bodyText) throws Exception
body
in class Rule
namespace
- the namespace URI of the matching element, or an
empty string if the parser is not namespace aware or the element has
no namespacename
- the local name if the parser is namespace aware, or just
the element name otherwisebodyText
- The body text of this elementException
public void end(String namespace, String name) throws Exception
public void finish() throws Exception
protected void processMethodCallResult(Object result)
result
- the Object returned by the method invoked, possibly nullCopyright © 2000-2014 Apache Software Foundation. All Rights Reserved.