Java IO流操作 (II)

缓冲流

/*

 * BufferedWriter: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。

 * BufferedReader: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。

 */

public class BufferedStreamDemo {

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

		//创建输出缓冲流对象

		/*

		BufferedWriter bw = new BufferedWriter(new FileWriter("bw.txt"));

		bw.write("hello");

		//bw.flush();

		bw.close();

		*/

		//创建输入缓冲流对象

		BufferedReader br = new BufferedReader(new FileReader("FileWriterDemo.java"));

		/*

		//一次读写一个字符

		int ch;

		while((ch=br.read())!=-1){

			System.out.print((char)ch);

		}

		*/

		//一次读写一个字符数组

		char[] chs = new char[1024];

		int len;

		while((len=br.read(chs))!=-1) {

			System.out.print(new String(chs,0,len));

		}

		//释放资源

		br.close();

	}

}

缓冲流的特殊功能

/*

 * 缓冲流的特殊功能：

 * BufferedWriter

 * 		void newLine():写一个换行符，这个换行符由系统决定

 * BufferedReader

 * 		String readLine():一次读取一行数据，但是不读取换行符

 */

public class BufferedStreamDemo {

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

		/*

		BufferedWriter bw = new BufferedWriter(new FileWriter("bw2.txt"));

		for(int x=0; x<10; x++) {

			bw.write("hello"+x);

			//bw.write("\r\n");

			bw.newLine();

			bw.flush();

		}

		bw.close();

		*/

		BufferedReader br = new BufferedReader(new FileReader("br.txt"));

		String line;

		//1:br.readLine()

		//2:line=br.readLine()

		//3:line != null

		while((line=br.readLine())!=null) {

			System.out.println(line);

		}

		br.close();

	}

}