package com.janson.day20180827;

import java.io.FileNotFoundException;

import java.io.FileReader;

import java.io.FileWriter;

import java.io.IOException;

public class TestFileWriter {

    public static void main(String[] args) {

        FileReader r = null;

        FileWriter w = null;

        int f = 0;

        int num = 0;

        try {

            r = new FileReader(System.getProperty("user.dir") + "/src/com/janson/day20180827/TestFileReader.java");

            w = new FileWriter("D:/javaExample/file/TestFileReader.txt");

            while ((f = r.read()) !=-1) {

                w.write(f);

                num ++;

            }

            w.flush();

            w.close();

            System.out.println("写入文件成功，共写入了" + num + "个字节");

        }catch (FileNotFoundException e1) {

            e1.printStackTrace();

            System.out.println("找不到相应文件");

            System.exit(-1);

        }catch (IOException e2) {

            e2.printStackTrace();

            System.out.println("写入文件失败");

            System.exit(-1);

        }

    }

}

import java.io.*;

public class TestFileWriter2 {

    public static void main(String[] args) throws Exception {

        FileReader fr = new FileReader("d:/java/io/TestFileWriter2.java");

        FileWriter fw = new FileWriter("d:/java/io/TestFileWriter2.bak");

        int b;

        while((b = fr.read()) != -1) {

            fw.write(b);

        }

        fr.close();

        fw.close();

    }

}

import java.io.*;

public class FileCopy {

  public static void main(String[] args) {

      int b = 0;

      FileReader in = null;

      FileWriter out = null;

      try {

        in = new FileReader("d:/share/java/HelloWorld.java");

        out = new FileWriter("d:/share/java/io/HW.java");

        while((b=in.read())!=-1){

          out.write(b);

        }

        out.close();

        in.close(); 

      } catch (FileNotFoundException e2) {

        System.out.println("找不到指定文件"); System.exit(-1);

      } catch (IOException e1) {

        System.out.println("文件复制错误"); System.exit(-1);

      }

      System.out.println("文件已复制");

  }

}