JAVA.io读写文件方式汇总

//读取文件(字节流)
    InputStream in = new FileInputStream("d:\\1.txt");
    //写入相应的文件
    OutputStream out = new FileOutputStream("d:\\2.txt");
    //读取数据
    //一次性取多少字节
    byte[] bytes = new byte[2048];
    //接受读取的内容(n就代表的相关数据，只不过是数字的形式)
    int n = -1;
    //循环取出数据
    while ((n = in.read(bytes,0,bytes.length)) != -1) {
      //转换成字符串
      String str = new String(bytes,0,n,"GBK"); #这里可以实现字节到字符串的转换，比较实用
      System.out.println(str);
      //写入相关文件
      out.write(bytes, 0, n);
    }
    //关闭流
    in.close();
    out.close();

//读取文件(缓存字节流)
    BufferedInputStream in = new BufferedInputStream(new FileInputStream("d:\\1.txt"));
    //写入相应的文件
    BufferedOutputStream out = new BufferedOutputStream(new FileOutputStream("d:\\2.txt"));
    //读取数据
    //一次性取多少字节
    byte[] bytes = new byte[2048];
    //接受读取的内容(n就代表的相关数据，只不过是数字的形式)
    int n = -1;
    //循环取出数据
    while ((n = in.read(bytes,0,bytes.length)) != -1) {
      //转换成字符串
      String str = new String(bytes,0,n,"GBK");
      System.out.println(str);
      //写入相关文件
      out.write(bytes, 0, n);
    }
    //清楚缓存
    out.flush();
    //关闭流
    in.close();
    out.close();

//读取文件(字节流)
    InputStreamReader in = new InputStreamReader(new FileInputStream("d:\\1.txt"),"GBK");
    //写入相应的文件
    OutputStreamWriter out = new OutputStreamWriter(new FileOutputStream("d:\\2.txt"));
    //读取数据
    //循环取出数据
    byte[] bytes = new byte[1024];
    int len = -1;
    while ((len = in.read()) != -1) {
      System.out.println(len);
      //写入相关文件
      out.write(len);
    }
    //清楚缓存
    out.flush();
    //关闭流
    in.close();
    out.close();

//读取文件(字符流)
    BufferedReader in = new BufferedReader(new InputStreamReader(new FileInputStream("d:\\1.txt"),"GBK"));#这里主要是涉及中文
    //BufferedReader in = new BufferedReader(new FileReader("d:\\1.txt")));
    //写入相应的文件
    BufferedWriter out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream("d:\\2.txt"),"GBK"));
    //BufferedWriter out = new BufferedWriter(new FileWriter("d:\\2.txt"))；
    //读取数据
    //循环取出数据
    String str = null;
    while ((str = in.readLine()) != null) {
      System.out.println(str);
      //写入相关文件
      out.write(str);
      out.newLine();
    }
    
    //清楚缓存
    out.flush();
    //关闭流
    in.close();
    out.close();

//读取文件(字节流)
    Reader in = new InputStreamReader(new FileInputStream("d:\\1.txt"),"GBK");
    //写入相应的文件
    PrintWriter out = new PrintWriter(new FileWriter("d:\\2.txt"));
    //读取数据
    //循环取出数据
    byte[] bytes = new byte[1024];
    int len = -1;
    while ((len = in.read()) != -1) {
      System.out.println(len);
      //写入相关文件
      out.write(len);
    }
    //清楚缓存
    out.flush();
    //关闭流
    in.close();
    out.close();