org.apache.accumulo.examples.simple.filedata.KeyUtil.java Source code

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Here is the source code for org.apache.accumulo.examples.simple.filedata.KeyUtil.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 org.apache.accumulo.examples.simple.filedata;

import java.util.ArrayList;

import org.apache.hadoop.io.Text;

/**
 * A utility for creating and parsing null-byte separated strings into/from Text objects.
 */
public class KeyUtil {
    public static final byte[] nullbyte = new byte[] { 0 };

    /**
     * Join some number of strings using a null byte separator into a text object.
     * 
     * @param s
     *          strings
     * @return a text object containing the strings separated by null bytes
     */
    public static Text buildNullSepText(String... s) {
        Text t = new Text(s[0]);
        for (int i = 1; i < s.length; i++) {
            t.append(nullbyte, 0, 1);
            t.append(s[i].getBytes(), 0, s[i].length());
        }
        return t;
    }

    /**
     * Split a text object using a null byte separator into an array of strings.
     * 
     * @param t
     *          null-byte separated text object
     * @return an array of strings
     */
    public static String[] splitNullSepText(Text t) {
        ArrayList<String> s = new ArrayList<String>();
        byte[] b = t.getBytes();
        int lastindex = 0;
        for (int i = 0; i < t.getLength(); i++) {
            if (b[i] == (byte) 0) {
                s.add(new String(b, lastindex, i - lastindex));
                lastindex = i + 1;
            }
        }
        s.add(new String(b, lastindex, t.getLength() - lastindex));
        return s.toArray(new String[s.size()]);
    }
}