DataCompression/FileHandler.java at master · kpaganopoulos/DataCompression · GitHub

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import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.util.ArrayList;

/**
 * This class encapsulates some static method used for file reading and writing.
 * @author Michael
 *
 */
public class FileHandler {

        private FileHandler(){}

        public static String readFile(String url, boolean withLineWrap){
                String result = "";
                try {
                        FileReader fr = new FileReader(url);
                        BufferedReader br = new BufferedReader(fr);
                        String temp = null;

                        if ( withLineWrap ) {
                                while ( ( temp=br.readLine() ) !=null ){
                                        result += (temp+"\n");
                                }
                        }
                        else {
                                while ( ( temp=br.readLine() ) !=null ){
                                        result += temp;
                                }
                        }

                } catch (FileNotFoundException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }
                return result;
        }


        public static void writeFile(String url, String text, boolean withLineWrap){
                try {
                        FileWriter fw = new FileWriter(url);
                        BufferedWriter bw = new BufferedWriter(fw);
                        char[] str = text.toCharArray();

                        for ( int i=0; i<str.length; i++ ) {
                                if ( withLineWrap && i%100==0 && i!=0 )
                                        bw.append('\n');
                                bw.append(str[i]);
                        }
                        bw.close();
                        fw.close();

                        System.out.println("Writing file completed!");
                } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }
        }

        public static void writeSymbolToFile(String url, ArrayList<Symbol> symbolList) {
                // TODO Auto-generated method stub
                try {
                        FileWriter fw = new FileWriter(url);
                        BufferedWriter bw = new BufferedWriter(fw);

                        for ( Symbol s: symbolList ){
                                /**
                                 * 由于换行符和空格没法表示，所以我就用了这么一个方法，对它们进行特殊处理
                                 */
                                if ( s.letter.equals("\n") ) {
                                        bw.write( "lineWrapper" + " " + s.probability + " " + s.low + " " + s.high );
                                }
                                else if ( s.letter.equals(" ") ){
                                        bw.write( "space" + " " + s.probability + " " + s.low + " " + s.high );
                                } else {
                                        bw.write( s.letter + " " + s.probability + " " + s.low + " " + s.high );
                                }
                                bw.newLine();
                        }
                        bw.close();
                        fw.close();

                        System.out.println("Writing file completed!");
                } catch (IOException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                }
        }

}