转换流：字符流和字节流之间的桥梁

用于处理程序的编码问题

 

OutputStreamWriter类：字符转字节流

写文本文件：

package demo;import java.io.FileOutputStream;import java.io.IOException;import java.io.OutputStreamWriter;public class Demo {    public static void main(String[] args) throws IOException {        writeGBK();        writeUTF8();    }    public static void writeGBK() throws IOException {        FileOutputStream fos = new FileOutputStream("d:\\gbk.txt");        OutputStreamWriter osw = new OutputStreamWriter(fos, "GBK");        osw.write("你好");// gbk的一个汉字是2个字节        osw.close();    }    public static void writeUTF8() throws IOException {        FileOutputStream fos = new FileOutputStream("d:\\utf8.txt");        OutputStreamWriter osw = new OutputStreamWriter(fos, "UTF-8");        osw.write("你好");// utf8的一个汉字是3个字节        osw.close();    }}

 

InputStreamReader类：

字节转字符流过程：

这里读取上面写的文本文件：

package demo;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStreamReader;public class Demo {    public static void main(String[] args) throws IOException {        readGBK();        readUTF8();    }    public static void readGBK() throws IOException {        FileInputStream fis = new FileInputStream("d:\\gbk.txt");        InputStreamReader isr = new InputStreamReader(fis);        char[] ch = new char[1024];        int len = isr.read(ch);        System.out.println(new String(ch, 0, len));    }    public static void readUTF8() throws IOException {        FileInputStream fis = new FileInputStream("d:\\utf8.txt");        InputStreamReader isr = new InputStreamReader(fis, "UTF-8");        char[] ch = new char[1024];        int len = isr.read(ch);        System.out.println(new String(ch, 0, len));    }}

 

这里注意，如果编码集和读取问文本不一致，就会发生乱码或者输出？的问题