I/O字符流

 

 

    /*
    * 编码格式
    * utf-8:国际标准通用
    * GBK:包含中文
    * ASICLL:美国标准 美国文字全部由26个字母组成，然后数字 128个
    * */
    public void utf8Test() throws UnsupportedEncodingException {

        String s="中国";
        byte[] defult=s.getBytes();
        System.out.println(Arrays.toString(defult));
        System.out.println(new String(defult,"UTF-8"));

        byte[] utf8=s.getBytes("UTF-8");
        System.out.println(Arrays.toString(utf8));

        byte[] gbk=s.getBytes("GBK");
        System.out.println(Arrays.toString(gbk));
        System.out.println(new String(gbk,"UTF-8"));

    }

    public void streamTest() throws IOException {
        String path="E:\\Java\\00_0\\2.txt";
        OutputStreamWriter osw=new OutputStreamWriter(new FileOutputStream(path,true),"UTF-8");
        osw.write("测试字符流");

        //字符流必须先flush():将写入缓存中的字符写入到文本。close的时候会自动调用
        osw.flush();

        InputStreamReader isr=new InputStreamReader(new FileInputStream(path),"UTF-8");
        char[] arr=new char[1024];
        int len;
        while ((len=isr.read(arr))!=-1){
            System.out.printf(new String(arr,0,len));
        }

        osw.close();
        isr.close();
    }


    /*
    * 简化版本
    * */
    public void fileTest() throws IOException {
        String path="E:\\Java\\00_0\\3.txt";
        FileWriter fw=new FileWriter(path, Charset.forName("UTF-8"),true);
        fw.write("测试FileWriter");
        fw.flush();

        FileReader fr=new FileReader(path,Charset.forName("UTF-8"));
        char[] arr=new char[1024];
        int len;
        while ((len=fr.read(arr))!=-1){
            System.out.println(new String(arr));
        }

        fw.close();
        fr.close();
    }


    /*
    * 一次一个字节读取
    * */
    public void fileTest1() throws IOException {
        String path="E:\\Java\\00_0\\3.txt";
        FileWriter fw=new FileWriter(path, Charset.forName("UTF-8"),true);
        fw.write("测试FileWriter");
        fw.flush();

        FileReader fr=new FileReader(path,Charset.forName("UTF-8"));

        int c;
        while ((c=fr.read())!=-1){
            System.out.print((char)c);
        }

        fw.close();
        fr.close();
    }


    public void buffedTest() throws IOException {
        String path="E:\\Java\\00_0\\4.txt";
        BufferedWriter bw=new BufferedWriter(new FileWriter(path));
        bw.write("测试BufferedWriter");

        bw.flush();

        BufferedReader br=new BufferedReader(new FileReader(path));
        char[] arr=new char[1024];
        int len;

        while ((len=br.read(arr))!=-1){
            System.out.println(new String(arr));
        }

        bw.close();
        br.close();
    }

    /*
    * 一次读取一行,字符缓存流的特有功能
    * */
    public void buffedTest1() throws IOException {
        String path="E:\\Java\\00_0\\4.txt";
        BufferedWriter bw=new BufferedWriter(new FileWriter(path,true));
        bw.write("测试BufferedWriter");

        bw.newLine();

        bw.write("测试BufferedWriter");

        bw.flush();

        BufferedReader br=new BufferedReader(new FileReader(path));
        char[] arr=new char[1024];

        String line  ;
        while ((line=br.readLine())!=null){

            System.out.println(line);
        }

        bw.close();
        br.close();
    }

    public void buffedTest2() throws IOException {
        String path="E:\\Java\\00_0\\4.txt";
        BufferedWriter bw=new BufferedWriter(new FileWriter(path,true));
        bw.newLine();
        bw.write("测试BufferedWriter");

        bw.flush();

        BufferedReader br=new BufferedReader(new FileReader(path));

        int c;

        while ((c=br.read())!=-1){
            System.out.print((char)c);
        }

        bw.close();
        br.close();
    }