inheritanceunsafegetresource.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) 2004, Tom Truscott <[e-mail]>
 *
 * 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 edu.umd.cs.findbugs.BugInstance;
import edu.umd.cs.findbugs.BugReporter;
import edu.umd.cs.findbugs.BytecodeScanningDetector;
import edu.umd.cs.findbugs.visitclass.Constants2;
import org.apache.bcel.classfile.JavaClass;
import org.apache.bcel.classfile.Method;

public class InheritanceUnsafeGetResource extends BytecodeScanningDetector implements Constants2 {

	private BugReporter bugReporter;
	private boolean classIsFinal;
//	private boolean methodIsVisibleToOtherPackages;
	private boolean classIsVisibleToOtherPackages;
//	private boolean methodIsFinal;
	private boolean methodIsStatic;
	int state = 0;
	int sawGetClass;
	boolean reportedForThisClass;

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


	public void visit(JavaClass obj) {
		classIsFinal = obj.isFinal();
		reportedForThisClass = false;
		classIsVisibleToOtherPackages = obj.isPublic() || obj.isProtected();
	}

	public void visit(Method obj) {
//		methodIsFinal = obj.isFinal();
		methodIsStatic = obj.isStatic();
//		methodIsVisibleToOtherPackages = obj.isPublic() || obj.isProtected();
		state = 0;
		sawGetClass = -100;
	}

	public void sawOpcode(int seen) {
		if (reportedForThisClass) return;

		switch (seen) {
		case ALOAD_0:
			state = 1;
			break;
		case INVOKEVIRTUAL:
			if (getClassConstantOperand().equals("java/lang/Class")
			        && (getNameConstantOperand().equals("getResource")
			        || getNameConstantOperand().equals("getResourceAsStream"))
			        && sawGetClass + 10 >= getPC()) {
				bugReporter.reportBug(new BugInstance(this, "UI_INHERITANCE_UNSAFE_GETRESOURCE", NORMAL_PRIORITY)
				        .addClassAndMethod(this)
				        .addSourceLine(this));
				reportedForThisClass = true;

			} else if (state == 1
			        && !methodIsStatic
			        // && !methodIsFinal
			        && !classIsFinal
			        && classIsVisibleToOtherPackages
			        // && methodIsVisibleToOtherPackages
			        && getNameConstantOperand().equals("getClass")
			        && getSigConstantOperand().equals("()Ljava/lang/Class;")) {
				sawGetClass = getPC();
			}
			state = 0;
			break;
		default:
			state = 0;
			break;
		}

	}

}