IO流--DataInputStream与DataOutputStream

/*DataInputStream与DataOutputStream：可以用于操作基本数据类型的数据流对象。 */import java.io.*;class DataStreamDemo {public static void main(String[] args) throws IOException {readData();writeData();readUTFDemo();// 用修改版utf-8写，只能用下面的它读。writeUTFDemo();// 使用字节转换流写文件OutputStreamWriter osw = new OutputStreamWriter(new FileInputStream("utf.txt"), "utf-8");// gbk--4个字节osw.write("你好");// 你好--标准版utf-8,6个字节osw.close();}public static void readData() throws IOException {DataInputStream dis = new DataInputStream(new FileInputStream("data.txt"));int num = dis.readInt();boolean b = dis.readBoolean();double d = dis.readDouble();System.out.println(num);System.out.println(b);System.out.println(d);}public static void writeData() throws IOException {DataOutputStream dos = new DataOutputStream(new FileOutputStream("data.txt"));dos.writeInt(234);dos.writeBoolean(true);dos.writeDouble(989.21);dos.close();}public static void readUTFDemo() throws IOException {DataInputStream dis = new DataInputStream(new FileInputStream("utfdate.txt"));String s = dis.readUTF();System.out.println(s);dis.close();}public static void writeUTFDemo() throws IOException {DataOutputStream dos = new DataOutputStream(new FileOutputStream("utfdate.txt"));dos.writeUTF("你好");// 有乱码+你好--8个字节，修改版的utf-8dos.close();}}