ObjectInputStream readFully()方法

java.io.ObjectInputStream.readFully(byte[] buf, int off, int len) 方法读取字节，方法一直阻塞直到所有字节被读出。

1 语法

public void readFully(byte[] buf)

2 参数

buf：读取数据的缓冲区。

off：数据的起始偏移量。

len：读取的最大字节数。

3 返回值

无

4 示例 

package com.yiidian;

/**
 * 一点教程网： http://www.yiidian.com
 */
/**
 * java.io.ObjectInputStream.readFully(byte[] buf, int off, int len)方法的例子
 */
import java.io.*;

public class Demo {
    public static void main(String[] args) {
        String s = "Hello World";

        try {
            // create a new file with an ObjectOutputStream
            FileOutputStream out = new FileOutputStream("test.txt");
            ObjectOutputStream oout = new ObjectOutputStream(out);

            // write something in the file
            oout.writeUTF(s);
            oout.flush();

            // create an ObjectInputStream for the file we created before
            ObjectInputStream ois = new ObjectInputStream(new FileInputStream("test.txt"));

            // read and print from index 0 to 7
            byte[] b = new byte[13];
            ois.readFully(b, 0, 7);
            String array = new String(b);
            System.out.println("" + array);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
}

输出结果为：

 Hello