转换流

迷南。 2023-06-27 03:16 30阅读 0赞

**转换流**  
输入：InputStreamReader 将一个字节的输入流转为字符的输入流  
输出：OutputStreamWriter 将一个字符的输出流转为字节的输出流

作用：提供字节流和字符流之间的转换操作

**InputStreamReader**  
InputStreamReader ： 实现字节的输入流到字符的输入流转换

@Test
        public void inputStreamReaderTest(){
            InputStreamReader isr= null;
            try
            {
                //  1. 指定需要操作的目标对象，创建需要的流
                FileInputStream is=new FileInputStream("hello.txt");
    
    //            isr = new InputStreamReader(is);
                //  指定编码参数
    
                //  2.创建对应的转换流
                isr = new InputStreamReader(is,"UTF-8");
    
                //  3.操作数据
                int read = isr.read();
                while (read != -1){
                    System.out.print((char) read);
                    read= isr.read();
                }
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            finally
            {
                try
                {
                    //  4.流关闭
                    if(isr != null)
                    isr.close();
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
        }

**OutputStreamWriter**  
OutputStreamWriter ： 实现字符的输出流到字节的输出流的转换

@Test
        public void outputStreamWriter(){
            OutputStreamWriter osw = null;
            try
            {
                FileOutputStream fos= new FileOutputStream("hello4.txt");
    
                osw = new OutputStreamWriter(fos);
    
                osw.write("OutputStreamWriter 操作");
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            finally
            {
                try
                {
                    if(osw != null)
                    osw.close();
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
    
    
        }

实现文本复制操作

@Test
        public void ioStream(){
            InputStreamReader isr = null;
            OutputStreamWriter osw = null;
            try
            {
                //  1.创建对应的流
                FileInputStream fis=new FileInputStream("hello.txt");
                FileOutputStream fos =new FileOutputStream("hello5.txt");
    
                 isr=new InputStreamReader(fis,"UTF-8");
                 osw= new OutputStreamWriter(fos,"gbk");
    
                //  2.操作对应的数据
                int read = isr.read();
                while (read != -1){
                    osw.write(read);
                    read = isr.read();
                }
            }
            catch (IOException e)
            {
                e.printStackTrace();
            }
            finally
            {
                //  3.关闭流
                try
                {
                    if(isr != null)
                    isr.close();
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
    
                try
                {
                    if(isr != null)
                    osw.close();
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
    
        }

运行结果  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0ODkyMDkx_size_16_color_FFFFFF_t_70]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0ODkyMDkx_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/202001021717581.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQ0ODkyMDkx,size_16,color_FFFFFF,t_70