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  • java读写文件

    读文件

    package tool;
    
    import java.io.BufferedReader;
    import java.io.BufferedWriter;
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.FileReader;
    import java.io.IOException;
    import java.io.OutputStreamWriter;
    
    public class ReadFile {
    
        public static void main(String[] args) throws IOException
        {
             File f=new File("F:/mernis/mernis.txt");
             
              int count=0;
              if(f.exists())
                  { 
                       FileReader read=new FileReader(f);
                       BufferedReader buff=new BufferedReader(read);
                    
                       boolean isEnd=false;
                       int i=0;
                       while(!isEnd)
                       {
                        String line;
                        i++;
                        //for (int i = 0; i <1000; i++) {
                            
                        //}
                        try {
                            line = buff.readLine();
                            if(line==null)
                                {
                                  isEnd=true;
                                }
                            else
                                {
                                    //System.out.println(line);
                                        if (i>=1&&i<=100) 
                                        {
                                            
                                            System.out.println(i+"##"+line);
                                        }
                                 count++;
                                }
                        } catch (Exception e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                        
                       }
                       
                       System.out.println("文件共有"+count+"行");
                       buff.close();
                   
                  }
             else
                  {
                   System.out.println("你输入的文件不存在,请正确使用:");
                  }
              
        }
    }
    ReadFile.java

    读写文件

    package tool;
    
    import java.io.BufferedReader;
    import java.io.BufferedWriter;
    import java.io.File;
    import java.io.FileOutputStream;
    import java.io.FileReader;
    import java.io.IOException;
    import java.io.OutputStreamWriter;
    
    public class TransferFile {
    
        public static void main(String[] args) throws IOException
        {
             File f=new File("F:/mernis/data_dump.sql");
             File filewrite=new File("F:/mernis/mernis.txt");
              int count=0;
              if(f.exists())
                  { 
                       FileReader read=new FileReader(f);
                       BufferedReader buff=new BufferedReader(read);
                       BufferedWriter out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(filewrite, true)));
                    
                       
                       boolean isEnd=false;
                       int i=0;
                       while(!isEnd)
                       {
                        String line;
                        i++;
                        //for (int i = 0; i <1000; i++) {
                            
                        //}
                        try {
                            line = buff.readLine();
                            if(line==null)
                                {
                                  isEnd=true;
                                }
                            else
                                {
                                    //System.out.println(line);
                                        if (i>=76&&i<=49611784) 
                                        {
                                            out.write(line+"
    ");
                                            //System.out.println(i);
                                            //System.out.println(i+"##"+line);
                                        }
                                 count++;
                                }
                        } catch (Exception e) {
                            // TODO Auto-generated catch block
                            e.printStackTrace();
                        }
                        
                       }
                       
                       System.out.println("文件共有"+count+"行");
                       buff.close();
                       out.close();
                   
                  }
             else
                  {
                   System.out.println("你输入的文件不存在,请正确使用:");
                  }
              
        }
    }
    TransferFile.java
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  • 原文地址:https://www.cnblogs.com/gpdm/p/6426368.html
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