转换流

1.转换流：属于字符流

• InputStreamReader：将一个字节的输入流转换为字符的输入流 解码
• OutputStreamWriter：将一个字符的输出流转换为字节的输出流 编码
  

2. 作用：提供字节流与字符流之间的转换

3. 解码：字节、字节数组 —>字符数组、字符串
   编码：字符数组、字符串 —> 字节、字节数组
   
   

public class InputStreamReaderTest {

/*
    此时处理异常的话，仍然应该使用try-catch-finally

    综合使用InputStreamReader和OutputStreamWriter
     */
    @Test
    public void test2() throws Exception {
        //1.造文件、造流
        File file1 = new File("dbcp.txt");
        File file2 = new File("dbcp_gbk.txt");

        FileInputStream fis = new FileInputStream(file1);
        FileOutputStream fos = new FileOutputStream(file2);

        InputStreamReader isr = new InputStreamReader(fis,"utf-8");
        OutputStreamWriter osw = new OutputStreamWriter(fos,"gbk");

        //2.读写过程
        char[] cbuf = new char[20];
        int len;
        while((len = isr.read(cbuf)) != -1){
            osw.write(cbuf,0,len);
        }

        //3.关闭资源
        isr.close();
        osw.close();

    }