FileReader與FileWriter

　　FileReader是Reader的子類，用於讀取字符流。FileWriter是Writer的子類，是用來讀取字符文件的便捷類。
　　

public static void test()throws Exception{
    File file = new File("e:/data.txt");
    FileReader fileReader = new FileReader(new File("e:/test.txt"));
    FileWriter fileWriter = new FileWriter(file);
    char[] c = new char[1024];
    int len;
    while((len = fileReader.read(c)) != -1){
        fileWriter.write(c,0,len);
    }
    fileReader.close();
    fileWriter.flush();
    fileWriter.close();
}