利用java怎么對(duì)文件目錄進(jìn)行讀寫(xiě)刪除

public String getInputMessage() throws IOException...{
         System.out.println("請(qǐng)輸入您的命令∶");
         byte buffer[]=new byte[1024];
         int count=System.in.read(buffer);
         char[] ch=new char[count-2];//最后兩位為結(jié)束符，刪去不要
         for(int i=0;i<count-2;i++)
             ch[i]=(char)buffer[i];
         String str=new String(ch);
         return str;
     }

 public void copyFile(String src,String dest) throws IOException...{
         FileInputStream in=new FileInputStream(src);
         File file=new File(dest);
         if(!file.exists())
             file.createNewFile();
         FileOutputStream out=new FileOutputStream(file);
         int c;
         byte buffer[]=new byte[1024];
         while((c=in.read(buffer))!=-1)...{
             for(int i=0;i<c;i++)
                 out.write(buffer[i]);        
         }
         in.close();
         out.close();
     }

public void PrintStreamDemo()...{
         try ...{
             FileOutputStream out=new FileOutputStream("D:/test.txt");
             PrintStream p=new PrintStream(out);
             for(int i=0;i<10;i++)
                 p.println("This is "+i+" line");
         } catch (FileNotFoundException e) ...{
             e.printStackTrace();
         }
     }

public void StringBufferDemo() throws IOException......{
         File file=new File("/root/sms.log");
         if(!file.exists())
             file.createNewFile();
         FileOutputStream out=new FileOutputStream(file,true);        
         for(int i=0;i<10000;i++)......{
             StringBuffer sb=new StringBuffer();
             sb.append("這是第"+i+"行:前面介紹的各種方法都不關(guān)用,為什么總是奇怪的問(wèn)題 ");
             out.write(sb.toString().getBytes("utf-8"));
         }        
         out.close();
     }

public void renameFile(String path,String oldname,String newname)...{
         if(!oldname.equals(newname))...{//新的文件名和以前文件名不同時(shí),才有必要進(jìn)行重命名
             File oldfile=new File(path+"/"+oldname);
             File newfile=new File(path+"/"+newname);
             if(newfile.exists())//若在該目錄下已經(jīng)有一個(gè)文件和新文件名相同，則不允許重命名
                 System.out.println(newname+"已經(jīng)存在！");
             else...{
                 oldfile.renameTo(newfile);
             }
         }         
     }

public void changeDirectory(String filename,String oldpath,String newpath,boolean cover)...{
         if(!oldpath.equals(newpath))...{
             File oldfile=new File(oldpath+"/"+filename);
             File newfile=new File(newpath+"/"+filename);
             if(newfile.exists())...{//若在待轉(zhuǎn)移目錄下，已經(jīng)存在待轉(zhuǎn)移文件
                 if(cover)//覆蓋
                     oldfile.renameTo(newfile);
                 else
                     System.out.println("在新目錄下已經(jīng)存在："+filename);
             }
             else...{
                 oldfile.renameTo(newfile);
             }
         }       
     }

public String FileInputStreamDemo(String path) throws IOException...{
         File file=new File(path);
         if(!file.exists()||file.isDirectory())
             throw new FileNotFoundException();
         FileInputStream fis=new FileInputStream(file);
         byte[] buf = new byte[1024];
         StringBuffer sb=new StringBuffer();
         while((fis.read(buf))!=-1)...{
             sb.append(new String(buf));    
             buf=new byte[1024];//重新生成，避免和上次讀取的數(shù)據(jù)重復(fù)
         }
         return sb.toString();
     }

public String BufferedReaderDemo(String path) throws IOException...{
         File file=new File(path);
         if(!file.exists()||file.isDirectory())
             throw new FileNotFoundException();
         BufferedReader br=new BufferedReader(new FileReader(file));
         String temp=null;
         StringBuffer sb=new StringBuffer();
         temp=br.readLine();
         while(temp!=null)...{
             sb.append(temp+" ");
             temp=br.readLine();
         }
         return sb.toString();
     }

public Document readXml(String path) throws DocumentException, IOException...{
         File file=new File(path);
         BufferedReader bufferedreader = new BufferedReader(new FileReader(file));
         SAXReader saxreader = new SAXReader();
         Document document = (Document)saxreader.read(bufferedreader);
         bufferedreader.close();
         return document;
     }

public void createDir(String path)...{
         File dir=new File(path);
         if(!dir.exists())
             dir.mkdir();
     }

public void createFile(String path,String filename) throws IOException...{
         File file=new File(path+"/"+filename);
         if(!file.exists())
             file.createNewFile();
     }

public void delFile(String path,String filename)...{
         File file=new File(path+"/"+filename);
         if(file.exists()&&file.isFile())
             file.delete();
     }

 public void delDir(String path)...{
         File dir=new File(path);
         if(dir.exists())...{
             File[] tmp=dir.listFiles();
             for(int i=0;i<tmp.length;i++)...{
                 if(tmp[i].isDirectory())...{
                     delDir(path+"/"+tmp[i].getName());
                 }
                 else...{
                     tmp[i].delete();
                 }
             }
             dir.delete();
         }
     }