finduncalledprivatemethods.java

一个查找java程序里bug的程序的源代码,该程序本身也是java写的,对提高java编程水平很有用

/*
 * FindBugs - Find bugs in Java programs
 * Copyright (C) 2003,2004 University of Maryland
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package edu.umd.cs.findbugs.detect;

import java.util.*;

import edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.BytecodeScanningDetector;
import edu.umd.cs.findbugs.MethodAnnotation;
import edu.umd.cs.findbugs.ba.ClassContext;
import org.apache.bcel.classfile.Method;

/**
 * Detector to find private methods that are never called.
 */
public class FindUncalledPrivateMethods extends BytecodeScanningDetector {
	private BugReporter bugReporter;
	private String className;
	private HashSet<MethodAnnotation> definedPrivateMethods, calledMethods;
	private HashSet<String> calledMethodNames;

	public FindUncalledPrivateMethods(BugReporter bugReporter) {
		this.bugReporter = bugReporter;
	}

	public void visitMethod(Method obj) {
		super.visitMethod(obj);
		if (obj.isPrivate()
		        && !getMethodName().equals("writeReplace")
		        && !getMethodName().equals("readResolve")
		        && !getMethodName().equals("readObject")
		        && !getMethodName().equals("readObjectNoData")
		        && !getMethodName().equals("writeObject")
		        && getMethodName().indexOf("debug") == -1
		        && getMethodName().indexOf("Debug") == -1
		        && getMethodName().indexOf("trace") == -1
		        && getMethodName().indexOf("Trace") == -1
		        && !getMethodName().equals("<init>")
		        && !getMethodName().equals("<clinit>")
		)
			definedPrivateMethods.add(MethodAnnotation.fromVisitedMethod(this));
	}

	public void sawOpcode(int seen) {
		switch (seen) {
		case INVOKEVIRTUAL:
		case INVOKESPECIAL:
		case INVOKESTATIC:
			if (getDottedClassConstantOperand().equals(className)) {
				MethodAnnotation called = new MethodAnnotation(getDottedClassConstantOperand(), getNameConstantOperand(), getSigConstantOperand());
				calledMethods.add(called);
				calledMethodNames.add(getNameConstantOperand().toLowerCase());
				// System.out.println("Saw call to " + called);

			}
			break;
		default:
			break;
		}
	}

	public void visitClassContext(ClassContext classContext) {
		definedPrivateMethods = new HashSet<MethodAnnotation>();
		calledMethods = new HashSet<MethodAnnotation>();
		calledMethodNames = new HashSet<String>();
		className = classContext.getJavaClass().getClassName();

		super.visitClassContext(classContext);

		definedPrivateMethods.removeAll(calledMethods);

		for (Iterator<MethodAnnotation> i = definedPrivateMethods.iterator(); i.hasNext();) {
			MethodAnnotation m = i.next();
			// System.out.println("Checking " + m);
			int priority = LOW_PRIORITY;
			String methodName = m.getMethodName();
			if (methodName.length() > 1
			        && calledMethodNames.contains(methodName.toLowerCase()))
				priority = NORMAL_PRIORITY;
			BugInstance bugInstance
			        = new BugInstance(this, "UPM_UNCALLED_PRIVATE_METHOD",
			                priority)
			        .addClass(this)
			        .addMethod(m);
			bugReporter.reportBug(bugInstance);
		}

		definedPrivateMethods = null;
		calledMethods = null;
	}
}

// vim:ts=4