1019课堂内容

  1 package text;
  2
  3 import java.io.*;
  4
  5 //文本文件操作类
  6 public class file {
  7
  8     private String fileName;
  9
 10     public String getFileName()
 11     {
 12         return fileName;
 13     }
 14     //构造
 15     private File file;
 16
 17     public  file(String fileName)
 18     {
 19         this.fileName = fileName;
 20
 21         file = new File(fileName);
 22     }
 23
 24         //创建文件
 25         public void create() throws IOException
 26         {
 27
 28
 29             if(!file.exists())//如果文件不存在
 30             {
 31                 file.createNewFile();
 32                 System.out.println("文件创建成功！");
 33             }
 34             else
 35             {
 36                 System.out.println("文件已存在！");
 37             }
 38         }
 39         //删除文件
 40         public void delete()
 41         {
 42             File file = new File(fileName);
 43
 44             if(file.exists())//如果文件存在
 45             {
 46                 file.delete();
 47                 System.out.println("删除成功！");
 48             }
 49             else
 50             {
 51                 System.out.println("文件不存在！");
 52             }
 53         }
 54         //修改内容
 55         public void edit(String strEdit) throws IOException//修改内容以参数形式传输进去
 56         {
 57             if(file.exists())
 58             {
 59                 FileWriter fw = new FileWriter(file);
 60
 61                 BufferedWriter bfw = new BufferedWriter(fw);
 62
 63                 bfw.write(strEdit);
 64
 65                 bfw.close();
 66             }
 67             else
 68             {
 69                 System.out.println("文件不存在！");
 70             }
 71         }
 72         //追加内容
 73         public void addLine(String strLine) throws IOException//新加行，并传输内容
 74         {
 75             if(file.exists())
 76             {
 77                 String str = readFile();
 78
 79                 FileWriter fw = new FileWriter(file);
 80
 81                 BufferedWriter bfw = new BufferedWriter(fw);
 82
 83                 //bfw.newLine();
 84
 85                 bfw.write(str+"\n"+strLine);
 86
 87                 bfw.close();
 88             }
 89             else
 90             {
 91                 System.out.println("文件不存在！");
 92             }
 93         }
 94         public String readFile() throws IOException
 95         {
 96             String rtn = "";
 97
 98             if(file.exists())
 99             {
100                 FileReader fr = new FileReader(file);
101
102                 BufferedReader br = new BufferedReader(fr);
103
104                 String s = "";
105
106                 while((s = br.readLine()) != null)
107                 {
108                     rtn += s + "\n";
109                 }
110                 br.close();
111             }
112             else
113             {
114                 System.out.println("文件不存在！");
115             }
116             return rtn;
117         }
118 }