FileDocCategorySizeDatePackage
SetNextRule.javaAPI DocApache Tomcat 6.0.147153Fri Jul 20 04:20:34 BST 2007org.apache.tomcat.util.digester

SetNextRule

public class SetNextRule extends Rule

Rule implementation that calls a method on the (top-1) (parent) object, passing the top object (child) as an argument. It is commonly used to establish parent-child relationships.

This rule now supports more flexible method matching by default. It is possible that this may break (some) code written against release 1.1.1 or earlier. See {@link #isExactMatch()} for more details.

Fields Summary
protected String
methodName
The method name to call on the parent object.
protected String
paramType
The Java class name of the parameter type expected by the method.
protected boolean
useExactMatch
Should we use exact matching. Default is no.
Constructors Summary
public SetNextRule(Digester digester, String methodName)
Construct a "set next" rule with the specified method name. The method's argument type is assumed to be the class of the child object.

param
digester The associated Digester
param
methodName Method name of the parent method to call
deprecated
The digester instance is now set in the {@link Digester#addRule} method. Use {@link #SetNextRule(String methodName)} instead.


        this(methodName);
public SetNextRule(Digester digester, String methodName, String paramType)
Construct a "set next" rule with the specified method name.

param
digester The associated Digester
param
methodName Method name of the parent method to call
param
paramType Java class of the parent method's argument (if you wish to use a primitive type, specify the corresonding Java wrapper class instead, such as java.lang.Boolean for a boolean parameter)
deprecated
The digester instance is now set in the {@link Digester#addRule} method. Use {@link #SetNextRule(String methodName,String paramType)} instead.


        this(methodName, paramType);
public SetNextRule(String methodName)
Construct a "set next" rule with the specified method name. The method's argument type is assumed to be the class of the child object.

param
methodName Method name of the parent method to call


        this(methodName, null);
public SetNextRule(String methodName, String paramType)
Construct a "set next" rule with the specified method name.

param
methodName Method name of the parent method to call
param
paramType Java class of the parent method's argument (if you wish to use a primitive type, specify the corresonding Java wrapper class instead, such as java.lang.Boolean for a boolean parameter)


        this.methodName = methodName;
        this.paramType = paramType;
Methods Summary
public voidend()
Process the end of this element.


        // Identify the objects to be used
        Object child = digester.peek(0);
        Object parent = digester.peek(1);
        if (digester.log.isDebugEnabled()) {
            if (parent == null) {
                digester.log.debug("[SetNextRule]{" + digester.match +
                        "} Call [NULL PARENT]." +
                        methodName + "(" + child + ")");
            } else {
                digester.log.debug("[SetNextRule]{" + digester.match +
                        "} Call " + parent.getClass().getName() + "." +
                        methodName + "(" + child + ")");
            }
        }

        // Call the specified method
        IntrospectionUtils.callMethod1(parent, methodName,
                child, paramType, digester.getClassLoader());
public booleanisExactMatch()

Is exact matching being used.

This rule uses org.apache.commons.beanutils.MethodUtils to introspect the relevent objects so that the right method can be called. Originally, MethodUtils.invokeExactMethod was used. This matches methods very strictly and so may not find a matching method when one exists. This is still the behaviour when exact matching is enabled.

When exact matching is disabled, MethodUtils.invokeMethod is used. This method finds more methods but is less precise when there are several methods with correct signatures. So, if you want to choose an exact signature you might need to enable this property.

The default setting is to disable exact matches.

return
true iff exact matching is enabled
since
Digester Release 1.1.1


    // --------------------------------------------------------- Public Methods


                                                                                                                            
       
    
        return useExactMatch;
public voidsetExactMatch(boolean useExactMatch)

Set whether exact matching is enabled.

See {@link #isExactMatch()}.

param
useExactMatch should this rule use exact method matching
since
Digester Release 1.1.1


        this.useExactMatch = useExactMatch;
public java.lang.StringtoString()
Render a printable version of this Rule.


        StringBuffer sb = new StringBuffer("SetNextRule[");
        sb.append("methodName=");
        sb.append(methodName);
        sb.append(", paramType=");
        sb.append(paramType);
        sb.append("]");
        return (sb.toString());