datafu.pig.hash.MD5.java Source code

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Here is the source code for datafu.pig.hash.MD5.java

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/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 datafu.pig.hash;

import java.math.BigInteger;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import org.apache.commons.codec.binary.Base64;

import datafu.pig.util.SimpleEvalFunc;

/**
 * Computes the MD5 value of a string and outputs it in hex (by default).
 * A method can be provided to the constructor, which may be either 'hex' or 'base64'.
 */
public class MD5 extends SimpleEvalFunc<String> {
    private final MessageDigest md5er;
    private final boolean isBase64;

    public MD5() {
        this("hex");
    }

    public MD5(String method) {
        if ("hex".equals(method)) {
            isBase64 = false;
        } else if ("base64".equals(method)) {
            isBase64 = true;
        } else {
            throw new IllegalArgumentException("Expected either hex or base64");
        }

        try {
            md5er = MessageDigest.getInstance("md5");
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException(e);
        }
    }

    public String call(String val) {
        if (isBase64) {
            return new String(Base64.encodeBase64(md5er.digest(val.getBytes())));
        } else {
            return String.format("%032x", new BigInteger(1, md5er.digest(val.getBytes())));
        }
    }
}