IO_处理流_字节缓冲流

字节流都加上缓冲流来提升功能。

package com.sxt.io;

import java.io.BufferedInputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;

/**
 * 四个步骤: 分段读取 文件字节输入流  加入缓冲流
 * 1、创建源
 * 2、选择流
 * 3、操作
 * 4、释放资源
 * 
 * @author 
 *
 */
public class BufferedTest01 {

	public static void main(String[] args) {
		File src = new File("abc.txt");
		//2、选择流
		InputStream  is =null;
		try {
			is =new BufferedInputStream(new FileInputStream(src));
			//3、操作 (分段读取)
			byte[] flush = new byte[1024]; //缓冲容器
			int len = -1; //接收长度
			while((len=is.read(flush))!=-1) {
				//字节数组-->字符串 (解码)
				String str = new String(flush,0,len);
				System.out.println(str);
			}		
		
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}finally {
			//4、释放资源
			try {
				if(null!=is) {
					is.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}			
		}
	}
	
	public static void test1() {
		//1、创建源
		File src = new File("abc.txt");
		//2、选择流
		InputStream  is =null;
		BufferedInputStream bis =null;
		try {
			is =new FileInputStream(src);
			bis = new BufferedInputStream(is);
			//3、操作 (分段读取)
			byte[] flush = new byte[1024]; //缓冲容器
			int len = -1; //接收长度
			while((len=is.read(flush))!=-1) {
				//字节数组-->字符串 (解码)
				String str = new String(flush,0,len);
				System.out.println(str);
			}		
		
		} catch (FileNotFoundException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}finally {
			//4、释放资源
			try {
				if(null!=is) {
					is.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
			try {
				if(null!=bis) {
					bis.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
}


package com.sxt.io;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;

/**
 * 文件字节输出流  加入缓冲流
 *1、创建源
 *2、选择流
 *3、操作(写出内容)
 *4、释放资源
 *  @author 
 *
 */
public class BufferedTest02 {

	public static void main(String[] args) {
		//1、创建源
		File dest = new File("dest.txt");
		//2、选择流
		OutputStream os =null;
		try {
			os =new BufferedOutputStream( new FileOutputStream(dest));
			//3、操作(写出)
			String msg ="IO is so easy\r\n";
			byte[] datas =msg.getBytes(); // 字符串-->字节数组(编码)
			os.write(datas,0,datas.length);
			os.flush();
		}catch(FileNotFoundException e) {		
			e.printStackTrace();
		}catch (IOException e) {
			e.printStackTrace();
		}finally{
			//4、释放资源
			try {
				if (null != os) {
					os.close();
				} 
			} catch (Exception e) {
			}
		}
	}
}


package com.sxt.io;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

/**
 * 文件拷贝：文件字节输入、输出流
 *
 *  @author 
 *
 */
public class Copy {

	public static void main(String[] args) {
		long t1 = System.currentTimeMillis();
		copy("IO开篇.mp4","IO-copy.mp4"); 
		long t2 = System.currentTimeMillis();
		System.out.println(t2-t1);
	}
	
	public static void copy(String srcPath,String destPath) {
		//1、创建源
			File src = new File(srcPath); //源头
			File dest = new File(destPath);//目的地
			//2、选择流		
			try( InputStream is=new BufferedInputStream(new FileInputStream(src));
					OutputStream os =new BufferedOutputStream( new FileOutputStream(dest));	) {				
				//3、操作 (分段读取)
				byte[] flush = new byte[1024]; //缓冲容器
				int len = -1; //接收长度
				while((len=is.read(flush))!=-1) {
					os.write(flush,0,len); //分段写出
				}			
				os.flush();
			}catch(FileNotFoundException e) {		
				e.printStackTrace();
			}catch (IOException e) {
				e.printStackTrace();
			}
	}
}