BufferedInputStream是带缓冲区的输入流，默认缓冲区大小是8M，能够减少访问磁盘的次数，提高文件读取性能；BufferedOutputStream是带缓冲区的输出流，能够提高文件的写入效率。BufferedInputStream与BufferedOutputStream分别是FilterInputStream类和FilterOutputStream类的子类，实现了装饰设计模式。

       BufferedInputStream类的例子如下：

import java.io.File;

import java.io.InputStream;

import java.io.FileInputStream;

import java.io.BufferedInputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.text.SimpleDateFormat;

import java.util.Date;

public class BufferedInputStreamDemo01{

	// 声明常量

        public static final int SIZE=1024;

	public static void main(String[] args){

	   //变量声明

           File f=null;

	   InputStream input=null;

	   BufferedInputStream bis=null;

           StringBuilder strBuild=null;

	   SimpleDateFormat sdf=null;

	   Date d=null;

           long start=0L;

	   long end=0L; 

          try{

		  sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");

		  strBuild=new StringBuilder();

                  start=System.currentTimeMillis();

		  d=new Date();

		  if(d!=null){

                  d.setTime(start);

	     }

          System.out.println("程序开始执行时间:"+sdf.format(d));

	  f=new File("d:"+File.separator+"demo.txt");

          input=new FileInputStream(f);

          // 指定文件带缓冲区的读取流且指定缓冲区大小为2KB

	  bis=new BufferedInputStream(input,2*SIZE);

          int bisLength=bis.available();

          int readLength=0;

          byte[] byteArray=new byte[SIZE];

          int tmp=0;

          while((tmp=bis.read(byteArray))!=-1){

                strBuild.append(new String(byteArray,0,tmp));

		System.out.println("每次读取字节数量:"+tmp);

		System.out.println("文件中剩余字节数:"+input.available());

	 }

          System.out.println(String.format("文件的大小:%d,缓冲区读取流返回的大小:%d",f.length(),bisLength));

	  System.out.println("文件的内容："+strBuild.toString());

	  System.out.println("字符串长度:"+strBuild.toString().length());

	  char[] cTmp=strBuild.toString().toCharArray();

	  System.out.println("字符串->字符数组长度:"+cTmp.length);

	  end=System.currentTimeMillis();

	  d=new Date();

	  if(d!=null){

	     d.setTime(end);

	  }

	  System.out.println("程序执行的结束时间:"+sdf.format(d));

	  System.out.println("<-------------******************---------------->");

	  System.out.println("程序执行时间(ms):"+(end-start)+"毫秒");

       }catch(FileNotFoundException ex){

          ex.printStackTrace();

       }catch(IOException ex){

          ex.printStackTrace();

       }finally{

         try{

               if(input!=null){

		 input.close();

		}

	       if(bis!=null){

		 bis.close();

	       }

         }catch(IOException ex){

           ex.printStackTrace();

         }

      }

   }

}

   BufferedOutputStream类的例子如下：

import java.io.File;

import java.io.OutputStream;

import java.io.FileOutputStream;

import java.io.BufferedOutputStream;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

public class BufferedOutputStreamDemo01{

        public static final int SIZE=1024;

        public static final String DRIVERNAME="oracle.jdbc.driver.OracleDriver";

        public static final String DBURL="jdbc:oracle:thin:@IP:1521:DB名称";

	public static final String USERNAME="用户名";

	public static final String PASSWORD="密码";

	static{

	   try{

	        // 加载驱动程序

	        Class.forName(DRIVERNAME);

	      }catch(ClassNotFoundException ex){

	        ex.printStackTrace();

	    }

	}

	public static void main(String[] args){

	   // 变量声明

	   File f=null;

	   OutputStream output=null;

	   BufferedOutputStream bos=null;

           Connection con=null;

	   PreparedStatement pst=null;

           ResultSet rs=null;

	   StringBuilder strBuild=null;

           try{

		  String sql=" select vendor_no,vendor_name,address,phone,email,zipcode from VENDOR";

		  con=new BufferedOutputStreamDemo01().getConnection();

                  // 获得数据库操作类

                  pst=new BufferedOutputStreamDemo01().getPst(con,sql);

                  // 获得结果集

		  rs=pst.executeQuery();

		  f=new File("F:"+File.separator+"tmp.txt");

		  output=new FileOutputStream(f,false);

		  bos=new BufferedOutputStream(output,SIZE*4);

		  while(rs.next()){

                        strBuild=new StringBuilder();

			// 店号

			strBuild.append(rs.getString("vendor_no"));

			strBuild.append(",");

                        // 店名

			strBuild.append(rs.getString("vendor_name"));

			strBuild.append(",");

			// 地址

			strBuild.append(rs.getString("address"));

			strBuild.append(",");

			// 电话

			strBuild.append(rs.getString("phone"));

			strBuild.append(",");

                        // 邮件

			strBuild.append(rs.getString("email"));

			strBuild.append(",");

                        // 邮政编码

			strBuild.append(rs.getString("zipcode"));

			strBuild.append("\n");

                        bos.write(strBuild.toString().getBytes("utf-8"));

		  }

           }catch(IOException ex1){

               ex1.printStackTrace();

	   }catch(SQLException ex){

	       ex.printStackTrace();

	   }finally{

               try{

			 // 关闭流

			 if(output!=null){

			   output.close();

			 }

			 if(bos!=null){

                            bos.close();

			 }

			 //关闭数据库连接

			 if(rs!=null){

                            rs.close();

			 }

                         if(pst!=null){

                            pst.close();

			 }

                         if(con!=null){

			   con.close();

			 }

                 }catch(IOException ex){

	            ex.printStackTrace();

                 }catch(SQLException ex){

                    ex.printStackTrace();

	         }

	     }

	}

	/**

        **获得数据库连接

	**

	**/

	public static Connection getConnection(){

	   Connection con=null;

	   try{

	       // 获得数据库连接

	       con=DriverManager.getConnection(DBURL,USERNAME,PASSWORD);

	   }catch(SQLException ex){

	       ex.printStackTrace();

	   } 

	   return con;

	}

	/**

        **获得数据库操作类

	**/

	public static PreparedStatement getPst(Connection con,String sql){

            PreparedStatement pst=null;

	    try{

		  pst=con.prepareStatement(sql);

	       }catch(SQLException ex){

		  ex.printStackTrace();

	       } 

	    return pst;

	}

}