IO-demo

/**
 * Unit test for simple App.
 */
public class AppTest {
    /**
     * 从文件中读取内容
     */
    @Test
    public void inputstreamTest() {
        try {
            InputStream inputStream = new FileInputStream(new File("d:/hello.txt"));

            byte[] bytearr = new byte[200];
            int length = 0;
            while ((length = inputStream.read(bytearr, 0, 200)) != -1) {
                String str = new String(bytearr, 0, length,"gbk");
                System.out.println("str:"+str);
            }

            inputStream.close();
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

    }
    /**
     * 向文件中写入数据
     * @throws IOException
     */
    @Test
    public void outpustreamTest() throws IOException {
        String str = "你好，我是信息。";
        byte[] bytearr = str.getBytes("gbk");
        OutputStream outputStream = new FileOutputStream(new File("d:/aa.txt"));
        outputStream.write(bytearr);
        outputStream.close();
        
    }
    /**
     * 使用数组字节输入流方式读取
     * @throws IOException
     */
    @Test
    public void byteArrayInputStreamTest() throws IOException {
        String str = "你好";
        byte[] buff = str.getBytes("gbk");
        System.out.println("#buff:"+buff.length);
        InputStream inputstream = new ByteArrayInputStream(buff);
        int length = 0;
        while(-1!=(length=inputstream.read())) {
            System.out.println("length:"+length);
        }
    } 
    
    /**
     * 使用数组字节输出流向文件中写入
     * @throws IOException
     */
    @Test
    public void byteArrayOutputStreamTest() throws IOException{
        String str = "hello";
        byte[] buff = str.getBytes("gbk");
        
        ByteArrayOutputStream outputstream = new ByteArrayOutputStream();
        outputstream.write(buff);
        
        byte[] bytearr = outputstream.toByteArray();
        for(byte b : bytearr) {
            System.out.println((char)b);
        }
        OutputStream os = new FileOutputStream("d:/aa1.txt");
        outputstream.writeTo(os);
        os.close();
        outputstream.close();
        
        
    }
    
    @Test
    public void fileReaderTest() throws Exception {
        FileReader fReader = new FileReader("d:/aa.txt");
        char[] cbuf = new char[200];
        int length = 200;
        length = fReader.read(cbuf, 0, length);
        for(int i  = 0 ;i < cbuf.length;i++) {
            System.out.println(cbuf[i]);
        }
        fReader.close();
    }
    @Test
    public void fileWriterTest() throws Exception {
        FileWriter fWriter = new FileWriter("d:/bb.txt");
        String hhh = "你好我找二狗子";
        char[] cbuf = hhh.toCharArray();
        for(int i = 0 ;i < cbuf.length;i ++) {
            System.out.println(cbuf[i]);
        }
        fWriter.write(cbuf);
        
        fWriter.close();
    }
}