Java UTF8 sort(String inFile, int keyIndex, String outFile)

Description

sort

License

Apache License

Declaration

public static void sort(String inFile, int keyIndex, String outFile) 

Method Source Code

//package com.java2s;
/*//  w ww  .  java 2s. c o  m
 * (C) Copyright 2017 Shuangyan Liu
 * Shuangyan.Liu@open.ac.uk 
 * Knowledge Media Institute
 * The Open University, United Kingdom
 * 
 * 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.
 *
 */

import java.io.BufferedWriter;

import java.io.FileWriter;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;

import java.util.List;
import java.util.TreeMap;

public class Main {
    public static void sort(String inFile, int keyIndex, String outFile) {
        TreeMap<Integer, ArrayList<String>> tmap = new TreeMap<>();
        try {
            List<String> list = Files.readAllLines(Paths.get(inFile), StandardCharsets.UTF_8);
            String prevKey = "";
            ArrayList<String> sameKeyLines = new ArrayList<>();
            for (int i = 0; i < list.size(); i++) {
                String[] str = list.get(i).split("\t");
                String currentKey = str[keyIndex];
                if (prevKey.isEmpty())
                    prevKey = currentKey;
                if (!tmap.containsKey(Integer.valueOf(currentKey))) {
                    if (currentKey.equalsIgnoreCase(prevKey)) {
                        sameKeyLines.add(list.get(i));
                    } else {
                        tmap.put(Integer.valueOf(prevKey), sameKeyLines);
                        prevKey = currentKey;
                        sameKeyLines = new ArrayList<>();
                        sameKeyLines.add(list.get(i));
                    }
                }

            }
            tmap.put(Integer.valueOf(prevKey), sameKeyLines);

            BufferedWriter bw = new BufferedWriter(new FileWriter(outFile, false));
            for (Integer k : tmap.navigableKeySet()) {
                for (String line : tmap.get(k)) {
                    bw.write(line);
                    bw.write(System.lineSeparator());
                }
            }
            bw.close();
        } catch (IOException e) {

        }
    }
}

Related

1. makeUTF8()
2. moveFile(File inFile, File outFile)
3. newUTF8Decoder()
4. openFileUTF(String nom)
5. putUTF8(byte[] data, int offset, String str)
6. stringFromBytesUTF8(byte[] bytes)
7. stringToUtf8(String str)
8. stringToUTF8Bytes(String str)
9. toBytesUTF8(String s)