amr nbsp main 字符输入 txt not stat args
1.为什么字符流和字节流需要转换?
这是因为有一些时候系统给你提供的只有字节流,比如说System.in标准输入流。就是字节流。你想从他那里得到用户在键盘上的输入,只能是以转换流将它转换为Reader以方便自己的程序读取输入。再比如说Socket里的getInputStream()很明显只给你提供字节流,你要不行直接用,就得给他套个InputStreamReader()用来读取。网络传输来的字符。
2.字节流和字符流怎么转换?
2.1.字节流转换为字符流:InputStreamReader
2.2.字符输流转换为字节流:InputStreamWriter
3.具体应用
3.1 字节流转换为字符流
- package se.io;
- import java.io. * ;
- public class InputStreamReaderTest {
- public static void main(String[] args) {
- try {
- //构建字节输入流对象
- FileInputStream fileInputStream = new FileInputStream("E:\\test\\data3.txt");
- //构建字节字符转换流对象
- InputStreamReader inputStreamReader = new InputStreamReader(fileInputStream);
- //构建字符输入流对象
- BufferedReader bufferedReader = new BufferedReader(inputStreamReader);
- //读取数据
- char[] chars = new char[1024];
- int off = 0;
- while (bufferedReader.ready()) {
- off = bufferedReader.read(chars);
- }
- //打印输出
- String s = new String(chars, 0, off);
- System.out.println(s);
- //关闭流
- bufferedReader.close();
- inputStreamReader.close();
- fileInputStream.close();
- } catch(FileNotFoundException e) {
- e.printStackTrace();
- } catch(IOException e) {
- e.printStackTrace();
- }
- }
- }
3.2字符流转换为字节流
- package se.io;
- import java.io. * ;
- public class OutPutStreamWriterTest {
- public static void main(String[] args) {
- try {
- //构建输出流字节对象
- FileOutputStream fileOutputStream = new FileOutputStream("E:\\test\\data4.txt");
- //构建输出流字节字符转换对象
- OutputStreamWriter outputStreamWriter = new OutputStreamWriter(fileOutputStream);
- //构建字符输出流对象
- BufferedWriter bufferedWriter = new BufferedWriter(outputStreamWriter);
- //构建数据
- char[] chars = new char[3];
- chars[0] = ‘a‘;
- chars[1] = ‘b‘;
- chars[2] = ‘中‘;
- //输出数据
- bufferedWriter.write(chars);
- //关闭流
- bufferedWriter.close();
- outputStreamWriter.close();
- fileOutputStream.close();
- } catch(FileNotFoundException e) {
- e.printStackTrace();
- } catch(IOException e) {
- e.printStackTrace();
- }
- }
- }
java 核心编程——IO流之字符流和字节流相互转换(四)
来源: http://www.bubuko.com/infodetail-2305654.html