缓冲IO流

缓冲流
1.BufferedInputStream:缓冲字节输入流 
2.BufferedOutPutStream:缓冲字节输出流
3.BufferedReader：缓冲字符输入流
4.BufferedWriter:缓冲字符输出流

 

package file;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

//复制文件


public class test05 {
    
    public static void main(String[] args) throws IOException {
        copyFile("E:/java/read.txt","E:/java/hello.txt");
    }
    
    //复制文件
    
    public static void copyFile(String srcPath,String destPath) throws IOException {
        
        //选择IO流
        //1.从srcPath文件读取：FileInputStream
        //2.把数据写到destPath ;FileOutputStream
        
        FileInputStream fis = new FileInputStream(srcPath);
        FileOutputStream fos= new FileOutputStream(destPath);
        
        
        //一边读一边写
        
        byte[] data=new byte[1024];
        int len;
        while((len=fis.read(data))!=-1) {
            //fos.write(data);//最后一次，可能遗留了上次的内容
            fos.write(data,0,len);
        }
                
        //关闭IO流
        fos.close();
        fis.close();
        
        
    }

}

package file;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;

/*
缓冲流IO流
 1.BufferedInputStream:缓冲字节输入流  
 2.BufferedOutPutStream:缓冲字节输出流
 3.BufferedReader：缓冲字符输入流
 4.BufferedWriter:缓冲字符输出流
 
 数据的流向：srcPath-->fis-->bis-->字节数组-->bos-->fos-->destPath
 */


public class test06 {
    
    //复制大文件
    
    public static void main(String[] args) throws IOException {
        copyFile("E:/java/read.txt","E:/java/hello.txt");
    }
    
    public static void copyFile(String srcPath,String destPath) throws IOException {
            
            //选择IO流
            
            
            FileInputStream fis = new FileInputStream(srcPath);
            FileOutputStream fos= new FileOutputStream(destPath);
            
            //缓冲区提高效率
            BufferedInputStream bis = new BufferedInputStream(fis);
            BufferedOutputStream bos=new BufferedOutputStream(fos);
            
            
            //一边读一边写
            
            byte[] data=new byte[1024];
            int len;
            while((len=bis.read(data))!=-1) {
                //fos.write(data);//最后一次，可能遗留了上次的内容
                bos.write(data,0,len);
            }
                    
            //关闭IO流
            bis.close();
            fis.close();
            
            bos.close();
            fos.close();
            
            
        }

}

 

package file;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;


/*
 传统try...catch
try{}
catch(异常类型 e){}
finally{资源关闭}

try...with..resource
try(资源的申明){}
catch(异常类型 e){}
 */

public class test07 {
    public static void main(String[] args) throws IOException {
        copyFile("E:/java/read.txt","E:/java/world.txt");
    }
    
    public static void copyFile(String srcPath,String destPath){
        
           try(
               
                FileInputStream fis = new FileInputStream(srcPath);
                FileOutputStream fos= new FileOutputStream(destPath);
                BufferedInputStream bis = new BufferedInputStream(fis);
                BufferedOutputStream bos=new BufferedOutputStream(fos);
                   )
           {
            
                
                byte[] data=new byte[1024];
                int len;
                while((len=bis.read(data))!=-1) {
                    //fos.write(data);//最后一次，可能遗留了上次的内容
                    bos.write(data,0,len);
                }
               
           }catch(FileNotFoundException e) {
               e.printStackTrace();
           }catch(IOException e) {
               e.printStackTrace();
           }
            
        }

}

 

package file;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.IOException;

/*BufferedReader:readLine()
纯文本数据*/
public class test08 {
    
    public static void main(String[] args) throws IOException {
        
        //创建IO流
        BufferedReader br=new BufferedReader(new FileReader("E:/java/hello.txt"));
        
        //读取
        String line;
        while((line=br.readLine())!=null) {
            System.out.println(line);
        }
        
        //关闭
        br.close();
        
    }
    

}