IO读写文件

读取文件


            FileReader fr = new FileReader("happy.txt");
            int len;
            while ((len=fr.read())!=-1)
            {
                System.out.print((char)len);
            }
            fr.close();

//      创建一个文件

            //方法一
            File file = new File("E:\\java\\hello\\hello.txt");
            System.out.println(file.createNewFile());

            //方法二
            File file3 = new File("E:\\java\\hello.txt");
            System.out.println(file3.createNewFile());
//      写入内容
            FileWriter fw = new FileWriter("happy1.txt");
            fw.write("happy new year!");
            fw.write("Good good study!");
            fw.write("Day Day up!");
            fw.close();


//      System读写取该文件

            InputStream in = System.in;
            PrintStream out = System.out;
            FileOutputStream fom = new FileOutputStream("zs.txt");
            byte[] bytes = new byte[1024];
            in.read(bytes);
            out.write(bytes);
            fom.write(bytes);
            fom.close();

            in.close();
            out.close();