home | career | drupal | java | mac | mysql | perl | scala | uml | unix

Groovy example source code file (VerifyClass.java)

This example Groovy source code file (VerifyClass.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Java - Groovy tags/keywords

abstractinsnnode, abstractinsnnode, analyzer, buildexception, buildexception, classnode, classreader, classreader, file, file, io, ioexception, methodnode, string, tracemethodvisitor, util

The Groovy VerifyClass.java source code

/*
 * Copyright 2003-2009 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.codehaus.groovy.ant;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.taskdefs.MatchingTask;
import org.objectweb.asm.ClassReader;
import org.objectweb.asm.ClassWriter;
import org.objectweb.asm.Label;
import org.objectweb.asm.tree.AbstractInsnNode;
import org.objectweb.asm.tree.ClassNode;
import org.objectweb.asm.tree.MethodNode;
import org.objectweb.asm.tree.analysis.Analyzer;
import org.objectweb.asm.tree.analysis.Frame;
import org.objectweb.asm.tree.analysis.SimpleVerifier;
import org.objectweb.asm.util.CheckClassAdapter;
import org.objectweb.asm.util.TraceMethodVisitor;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.List;

/**
 * Verify Class files. This task can take the following
 * arguments:
 * <ul>
 * <li>dir
 * </ul>
 * When this task executes, it will recursively scan the dir and
 * look for class files to verify.
 */
public class VerifyClass extends MatchingTask {
    private String topDir = null;
    private boolean verbose = false;

    public VerifyClass() {
    }

    public void execute() throws BuildException {
        if (topDir == null) throw new BuildException("no dir attribute is set");
        File top = new File(topDir);
        if (!top.exists()) throw new BuildException("the directory " + top + " does not exist");
        log("top dir is " + top);
        int fails = execute(top);
        if (fails == 0) {
            log("no bytecode problems found");
        } else {
            log("found " + fails + " failing classes");
        }
    }

    public void setDir(String dir) throws BuildException {
        topDir = dir;
    }

    public void setVerbose(boolean v) {
        verbose = v;
    }

    private int execute(File dir) {
        int fails = 0;
        File[] files = dir.listFiles();
        for (int i = 0; i < files.length; i++) {
            File f = files[i];
            if (f.isDirectory()) {
                fails += execute(f);
            } else if (f.getName().endsWith(".class")) {
                try {
                    boolean ok = readClass(f.getCanonicalPath());
                    if (!ok) fails++;
                } catch (IOException ioe) {
                    log(ioe.getMessage());
                    throw new BuildException(ioe);
                }
            }
        }
        return fails;
    }

    private boolean readClass(String clazz) throws IOException {
        ClassReader cr = new ClassReader(new FileInputStream(clazz));
        ClassNode ca = new ClassNode() {
            public void visitEnd() {
                //accept(cv);
            }
        };
        cr.accept(new CheckClassAdapter(ca), ClassWriter.COMPUTE_MAXS);
        boolean failed = false;

        List methods = ca.methods;
        for (int i = 0; i < methods.size(); ++i) {
            MethodNode method = (MethodNode) methods.get(i);
            if (method.instructions.size() > 0) {
                Analyzer a = new Analyzer(new SimpleVerifier());
                try {
                    a.analyze(ca.name, method);
                    continue;
                } catch (Exception e) {
                    e.printStackTrace();
                }
                final Frame[] frames = a.getFrames();

                if (!failed) {
                    failed = true;
                    log("verifying of class " + clazz + " failed");
                }
                if (verbose) log(method.name + method.desc);
                TraceMethodVisitor mv = new TraceMethodVisitor(null) {
                    public void visitMaxs(int maxStack, int maxLocals) {
                        StringBuffer buffer = new StringBuffer();
                        for (int i = 0; i < text.size(); ++i) {
                            String s = frames[i] == null ? "null" : frames[i].toString();
                            while (s.length() < maxStack + maxLocals + 1) {
                                s += " ";
                            }
                            buffer.append(Integer.toString(i + 100000).substring(1));
                            buffer.append(" ");
                            buffer.append(s);
                            buffer.append(" : ");
                            buffer.append(text.get(i));
                        }
                        if (verbose) log(buffer.toString());
                    }
                };
                for (int j = 0; j < method.instructions.size(); ++j) {
                    Object insn = method.instructions.get(j);
                    if (insn instanceof AbstractInsnNode) {
                        ((AbstractInsnNode) insn).accept(mv);
                    } else {
                        mv.visitLabel((Label) insn);
                    }
                }
                mv.visitMaxs(method.maxStack, method.maxLocals);
            }
        }
        return !failed;
    }

}

Other Groovy examples (source code examples)

Here is a short list of links related to this Groovy VerifyClass.java source code file:

new blog posts

 

Copyright 1998-2013 Alvin Alexander, alvinalexander.com
All Rights Reserved.