com.interface21.aop.framework.RegexpMethodPointcut.java Source code

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Here is the source code for com.interface21.aop.framework.RegexpMethodPointcut.java

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/*
 * The Spring Framework is published under the terms
 * of the Apache Software License.
 */

package com.interface21.aop.framework;

import java.lang.reflect.Method;

import org.aopalliance.intercept.AttributeRegistry;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.oro.text.regex.MalformedPatternException;
import org.apache.oro.text.regex.Pattern;
import org.apache.oro.text.regex.PatternMatcher;
import org.apache.oro.text.regex.Perl5Compiler;
import org.apache.oro.text.regex.Perl5Matcher;

/**
 * Perl5 regular expression pointcut bean.
 * JavaBean properties are:
 * <li>pattern: Perl5 regular expression for the fully-qualified method names to match
 * <li>interceptor: interceptor to invoke if the pointcut matches
 * Matching is based purely on method name. 
 * <br>
 * Note: the regular expression must be a match. For example,
 * <code>.*get.*</code> will match com.mycom.Foo.getBar().
 * <code>get.*</code> will not.
 * <p>
 * Currently using Jakarta ORO regular expression library.
 * Does not require J2SE 1.4, although it runs under 1.4.
 * @author Rod Johnson
 * @since July 22, 2003
 * @version $Id: RegexpMethodPointcut.java,v 1.3 2003/07/24 20:48:20 johnsonr Exp $
 */
public class RegexpMethodPointcut extends AbstractMethodPointcut implements StaticMethodPointcut {

    private Log logger = LogFactory.getLog(getClass());

    /** Regular expression to match */
    private String pattern;

    /** ORO's compiled form of this pattern */
    private Pattern compiledPattern;

    /** ORO pattern matcher to use */
    private PatternMatcher matcher;

    /**
     * @return the regular expression for method matching
     */
    public String getPattern() {
        return pattern;
    }

    /**
     * Set the regular expression defining methods to match
     * @param pattern Perl5 regular expression describing methods
     * to match
     */
    public void setPattern(String pattern) throws MalformedPatternException {
        this.pattern = pattern;
        Perl5Compiler compiler = new Perl5Compiler();
        // Compile the pattern to be threadsafe
        this.compiledPattern = compiler.compile(pattern, Perl5Compiler.READ_ONLY_MASK);
        this.matcher = new Perl5Matcher();
    }

    /**
     * Try to match the regular expression against
     * the fully qualified name of the method's declaring class, plus the
     * name of the method. Note that the declaring class is that class
     * that originally declared the method, not necessarily the class
     * that's currently exposing it.
     * For example, <code>java.lang.Object.hashCode</code> matches
     * any subclass of object's hashCode() method.
     * @see com.interface21.aop.framework.StaticMethodPointcut#applies(java.lang.reflect.Method, org.aopalliance.intercept.AttributeRegistry)
     */
    public boolean applies(Method m, AttributeRegistry attributeRegistry) {
        String patt = m.getDeclaringClass().getName() + "." + m.getName();
        boolean matched = this.matcher.matches(patt, this.compiledPattern);
        if (logger.isDebugEnabled())
            logger.debug("Candidate is: '" + patt + "'; pattern is " + this.compiledPattern.getPattern()
                    + "; matched=" + matched);
        return matched;
    }
}