IO流复制文件

Posted 2020-12-25 java-jiangtao-home

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package copyDemo;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;

public class CopyDemo {
    public static void main(String[] args) {
        copy();
        System.out.println("done");
    }
    public static void copy() {
        Reader reader = null;
        
        Writer writer = null;
        
        try {
            //创建文件读取对象
            reader = new FileReader("src/reader/Demo1.java");
            //创建文件写入对象
            writer = new FileWriter("Copy.java");
            int num = -1;
            
            while((num=reader.read()) != -1)
            {
                writer.write(num);
                
            }
            
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }catch(IOException e) {
            e.printStackTrace();
        }finally {
            try {
                if(writer != null)
                {
                    writer.close();
                    if(reader != null) {
                        reader.close();
                    }
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        
    }
}

package copyDemo;

import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;

public class CopyDemo2 {
    public static void main(String[] args) {
        copy();
        System.out.println("done");
    }
    public static void copy() {
        Reader reader = null;
        
        Writer writer = null;
        
        try {
            //创建文件读取对象
            reader = new FileReader("src/reader/Demo1.java");
            //创建文件写入对象
            writer = new FileWriter("Copy.java");
            int num = -1;
            char[] chs  =new char[1024];
            while((num=reader.read(chs)) != -1)
            {
                writer.write(chs,0,num);
                
            }
            
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }catch(IOException e) {
            e.printStackTrace();
        }finally {
            try {
                if(writer != null)
                {
                    writer.close();
                    if(reader != null) {
                        reader.close();
                    }
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        
    }
}

package copyDemo;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileNotFoundException;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.Flushable;
import java.io.IOException;
import java.io.Reader;
import java.io.Writer;

public class CopyDemo3 {
    public static void main(String[] args) {
        copy();
        System.out.println("done");
    }
    public static void copy() {
        Reader reader = null;
        
        Writer writer = null;
        
        
        BufferedReader br = null;
        
        BufferedWriter bw = null;
        try {
            //创建文件读取对象
            reader = new FileReader("src/reader/Demo1.java");
            //创建文件写入对象
            writer = new FileWriter("Copy1.java");
            
            br = new BufferedReader(reader);
            
            bw = new BufferedWriter(writer);
            
            String line = null;
            while((line = br.readLine()) != null)
                {
                    bw.write(line);
                    bw.newLine();
                }
            bw.flush();
        
            
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }catch(IOException e) {
            e.printStackTrace();
        }finally {
            try {
                if(writer != null)
                {
                    writer.close();
                    if(reader != null) {
                        reader.close();
                    }
                }
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        
    }
}

package copyDemo1;

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

public class Demo1 {
    public static void main(String[] args) {
        long start = System.currentTimeMillis();
        copy3();
        long end = System.currentTimeMillis();
        System.out.println("耗时"+(end-start)+"毫秒");
        /**
         * 总结：
         * 高效缓冲区再加上字节数组复制最快
         * 不是高效缓冲区，但是有字节数组第二
         * 高效缓冲区单个字符提取第三
         * 不是高效缓冲区，单个字符提取最慢 
         * 
         * 
         */
    }
    
    public static void copy() {
        InputStream in = null;
        OutputStream out = null;
        
        try {
            in = new FileInputStream("E:/1.chm");
            
            out = new FileOutputStream("E:/新建文件夹/1.chm");
            /**
             * !!!字符能做到的，字节肯定能做到。字节能做到的，字符不一定能做到
             * 字节可以拷贝文件，电影，拷贝的时候只要文件名不错就基本上没啥问题
             */
            
            
            int len = -1;
            while((len=in.read()) != -1) {
                out.write(len);
            }
            out.flush();
            
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(out != null) {
                try {
                    out.close();
                    if(in != null) {
                        in.close();
                    }
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            
        }
    }
    public static void copy1() {
        InputStream in = null;
        OutputStream out = null;
        
        try {
            in = new FileInputStream("E:/1.chm");
            out = new FileOutputStream("E:/新建文件夹/1.chm");
            
            /**
             * !!!字符能做到的，字节肯定能做到。字节能做到的，字符不一定能做到
             * 字节可以拷贝文件，电影，拷贝的时候只要文件名不错就基本上没啥问题
             */
            int len = -1;
            
            byte[] chs = new byte[1024];
            while((len=in.read(chs)) != -1) {
                out.write(chs, 0, len);
            }
            
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(out != null) {
                try {
                    out.close();
                    if(in != null) {
                        in.close();
                    }
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            
        }
    }
    public static void copy2() {
        InputStream in = null;
        OutputStream out = null;
        BufferedOutputStream bo = null;
        BufferedInputStream bp = null;
        try {
            in = new FileInputStream("E:/1.chm");
            out = new FileOutputStream("E:/新建文件夹/1.chm");
            bp = new BufferedInputStream(in);
            bo = new BufferedOutputStream(out);
            /**
             * !!!字符能做到的，字节肯定能做到。字节能做到的，字符不一定能做到
             * 字节可以拷贝文件，电影，拷贝的时候只要文件名不错就基本上没啥问题
             */
            int len = -1;
            
            byte[] chs = new byte[1024];
            while((len=bp.read(chs)) != -1) {
                bo.write(chs, 0, len);
            }
            bo.flush();
            
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(out != null) {
                try {
                    out.close();
                    if(in != null) {
                        in.close();
                    }
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            
        }
    }
    public static void copy3() {
        InputStream in = null;
        OutputStream out = null;
        BufferedOutputStream bo = null;
        BufferedInputStream bp = null;
        try {
            in = new FileInputStream("E:/1.chm");
            out = new FileOutputStream("E:/新建文件夹/1.chm");
            bp = new BufferedInputStream(in);
            bo = new BufferedOutputStream(out);
            /**
             * !!!字符能做到的，字节肯定能做到。字节能做到的，字符不一定能做到
             * 字节可以拷贝文件，电影，拷贝的时候只要文件名不错就基本上没啥问题
             */
            int len = -1;
            
        
            while((len=bp.read()) != -1) {
                bo.write(len);
            }
            bo.flush();
            
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        }catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(out != null) {
                try {
                    out.close();
                    if(in != null) {
                        in.close();
                    }
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            
        }
    }
}

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