Java——新IO 缓冲区与Buffer

缓冲区和Buffer

import java.nio.IntBuffer;

//=================================================
// File Name       :	IntBuffer_demo
//------------------------------------------------------------------------------
// Author          :	Common

//主类
//Function        : 	IntBuffer_demo
public class IntBuffer_demo {

	public static void main(String[] args) {
		// TODO 自动生成的方法存根
		IntBuffer buf = IntBuffer.allocate(10);			//开辟10个大小的缓冲区
		System.out.print("1.写入数据之前的position、limit和capacity");
		System.out.println("position="+buf.position()+"、limit="+buf.limit()+"、capacity="+buf.capacity());
		int temp[] = {3,5,7};					//定义整型数组
		buf.put(3);									//向缓冲区写入数据
		buf.put(temp);							//向缓冲区中写入一组数据
		System.out.print("2.写入数据之后的position、limit和capacity");
		System.out.println("position="+buf.position()+"、limit="+buf.limit()+"、capacity="+buf.capacity());
		buf.flip();						//重设缓冲区，改变指针
		System.out.print("3.准备输出数据时的position、limit和capacity");
		System.out.println("position="+buf.position()+"、limit="+buf.limit()+"、capacity="+buf.capacity());
		while(buf.hasRemaining()){
			int x = buf.get();
			System.out.print(x+"、");
		}
	}

}

创建子缓冲区

import java.nio.IntBuffer;

//=================================================
// File Name       :	IntBuffer_demo
//------------------------------------------------------------------------------
// Author          :	Common

//主类
//Function        : 	IntBuffer_demo
public class IntBuffer_demo {

	public static void main(String[] args) {
		// TODO 自动生成的方法存根

		IntBuffer buf = IntBuffer.allocate(10);			//开辟10个大小的缓冲区
		IntBuffer sub = null;											//定义缓冲区对象
		for(int i=0;i<10;i++){
			buf.put(2*i+1);
		}
		buf.position(2);
		buf.limit(6);
		sub = buf.slice();				//开辟子缓冲区
		for(int i=0;i<sub.capacity();i++){
			int temp = sub.get(i);
			sub.put(temp-1);
		}
		buf.flip();			//重设缓冲区
		buf.limit(buf.capacity());	//设置limit
		System.out.println("主缓冲区中的内容：");
		while(buf.hasRemaining()){
			int x = buf.get();					//取出当前内容
			System.out.print(x+"、");
		}
	}

}

import java.nio.IntBuffer;

//=================================================
// File Name       :	IntBuffer_demo
//------------------------------------------------------------------------------
// Author          :	Common

//主类
//Function        : 	IntBuffer_demo
public class IntBuffer_demo {

	public static void main(String[] args) {
		// TODO 自动生成的方法存根

		IntBuffer buf = IntBuffer.allocate(10);			//开辟10个大小的缓冲区
		IntBuffer read = null;											//定义缓冲区对象
		for(int i=0;i<10;i++){
			buf.put(2*i+1);
		}
		read = buf.asReadOnlyBuffer();			//创建只读缓冲区
		buf.flip();			//重设缓冲区
		System.out.println("主缓冲区中的内容：");
		while(buf.hasRemaining()){
			int x = buf.get();					//取出当前内容
			System.out.print(x+"、");
		}
		System.out.println();
		read.put(30);			//错误，不可写
	}

}