com.clariano.avaj.ByteStreamStructureLearner.java Source code

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Here is the source code for com.clariano.avaj.ByteStreamStructureLearner.java

Source

/**
 *  Copyright 2012 Phil Spencer
 *
 *  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 com.clariano.avaj;

import java.io.File;
import java.io.IOException;

import org.apache.commons.io.FileUtils;

public class ByteStreamStructureLearner {
    private final byte[] bytes;
    private final File classfile;

    public ByteStreamStructureLearner(File classFile) {
        this.classfile = classFile;
        try {
            bytes = FileUtils.readFileToByteArray(this.classfile);
        } catch (IOException ex) {
            throw new RuntimeException(ex);
        }
    }

    public void learn() {
        // Check for the CAFEBABE magic number
        if ((bytes[0] & 0xFF) == 0xCA && (bytes[1] & 0xFF) == 0xFE && (bytes[2] & 0xFF) == 0xBA
                && (bytes[3] & 0xFF) == 0xBE) {
            System.err.println(this.classfile.getAbsolutePath() + " is a Java class file");
        } else {
            System.err.println(this.classfile.getAbsolutePath() + " is not a Java class file");
        }
    }

}