Buffered流为缓冲流。BufferedReader可以从字符输入流中读取文本，缓冲各个字符，从而实现字符、数组和行的高效读取。BufferedWriter可以将文本写入字符输出流，缓冲各个字符，从而提供单个字符、数组和字符串的高效写入。
　　

 public static void test2()throws Exception{
        File file1 = new File("e:/test.txt");
        File file = new File("e:/data.txt");
        Reader reader = new FileReader(file);
        Writer writer = new FileWriter(file1);
        BufferedReader bufferedReader = new BufferedReader(reader);
        BufferedWriter bufferedWriter = new BufferedWriter(writer);
        char[] c = new char[1024];
        int len;
        long l = System.currentTimeMillis();
        while((len = bufferedReader.read(c)) != -1){
            bufferedWriter.write(c,0,len);
        }
        long l1 = System.currentTimeMillis();
        System.out.print(l1 - l);
    }

readLine() 读取一个文本行。通过下列字符之一即可认为某行已终止：换行 (‘\n’)、回车 (‘\r’) 或回车后直接跟着换行。

public static void test3()throws Exception{
File file = new File(“e:/data.txt”);
Reader reader = new FileReader(file);
BufferedReader bufferedReader = new BufferedReader(reader);
String tem = null;
while((tem = bufferedReader.readLine()) != null){
System.out.println(tem);
}
reader.close();
bufferedReader.close();
}