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[资料收集]Java-Java文件操作大全
阅读量:6692 次
发布时间:2019-06-25

本文共 11033 字,大约阅读时间需要 36 分钟。

一、Java文件操作代码

[来源]http://uujava0322.iteye.com/blog/1045876

1     //1.创建文件夹   2     //import java.io.*;   3     File myFolderPath = new File(str1);   4     try {   5         if (!myFolderPath.exists()) {   6            myFolderPath.mkdir();   7         }   8     }   9     catch (Exception e) {  10         System.out.println("新建目录操作出错");  11         e.printStackTrace();  12     }   13  14     //2.创建文件  15     //import java.io.*;  16     File myFilePath = new File(str1);  17     try {  18         if (!myFilePath.exists()) {  19             myFilePath.createNewFile();  20         }  21         FileWriter resultFile = new FileWriter(myFilePath);  22         PrintWriter myFile = new PrintWriter(resultFile);  23         myFile.println(str2);  24         resultFile.close();  25     }  26     catch (Exception e) {  27         System.out.println("新建文件操作出错");  28         e.printStackTrace();  29     }   30  31     //3.删除文件  32     //import java.io.*;  33     File myDelFile = new File(str1);  34     try {  35         myDelFile.delete();  36     }  37     catch (Exception e) {  38         System.out.println("删除文件操作出错");  39         e.printStackTrace();  40     }   41  42     //4.删除文件夹  43     //import java.io.*;  44     File delFolderPath = new File(str1);  45     try {  46         delFolderPath.delete(); //删除空文件夹  47     }  48     catch (Exception e) {  49         System.out.println("删除文件夹操作出错");  50         e.printStackTrace();  51     }   52  53     //5.删除一个文件下夹所有的文件夹  54     //import java.io.*;  55     File delfile=new File(str1);  56     File[] files=delfile.listFiles();  57     for(int i=0;i
folderList = new LinkedList
(); 153 folderList.add(str1); 154 while (folderList.size() > 0) { 155 File file = new File(folderList.peek()); 156 folderList.removeLast(); 157 File[] files = file.listFiles(); 158 ArrayList
fileList = new ArrayList
(); 159 for (int i = 0; i < files.length; i++) { 160 if (files[i].isDirectory()) { 161 folderList.add(files[i].getPath()); 162 } else { 163 fileList.add(files[i]); 164 } 165 } 166 for (File f : fileList) { 167 str2=f.getAbsoluteFile(); 168 str3 169 } 170 } 171 172 //13.复制文件夹 173 //import java.io.*; 174 //import java.util.*; 175 LinkedList
folderList = new LinkedList
(); 176 folderList.add(str1); 177 LinkedList
folderList2 = new LinkedList
(); 178 folderList2.add(str2+ str1.substring(str1.lastIndexOf("\\"))); 179 while (folderList.size() > 0) { 180 (new File(folderList2.peek())).mkdirs(); // 如果文件夹不存在 则建立新文件夹 181 File folders = new File(folderList.peek()); 182 String[] file = folders.list(); 183 File temp = null; 184 try { 185 for (int i = 0; i < file.length; i++) { 186 if (folderList.peek().endsWith(File.separator)) { 187 temp = new File(folderList.peek() + File.separator 188 + file[i]); 189 } else { 190 temp = new File(folderList.peek() + File.separator + file[i]); 191 } 192 if (temp.isFile()) { 193 FileInputStream input = new FileInputStream(temp); 194 FileOutputStream output = new FileOutputStream( 195 folderList2.peek() + File.separator + (temp.getName()).toString()); 196 byte[] b = new byte[5120]; 197 int len; 198 while ((len = input.read(b)) != -1) { 199 output.write(b, 0, len); 200 } 201 output.flush(); 202 output.close(); 203 input.close(); 204 } 205 if (temp.isDirectory()) { // 如果是子文件夹 206 for (File f : temp.listFiles()) { 207 if (f.isDirectory()) { 208 folderList.add(f.getPath()); 209 folderList2.add(folderList2.peek() 210 + File.separator + f.getName()); 211 } 212 } 213 } 214 } 215 } catch (Exception e) { 216 //System.out.println("复制整个文件夹内容操作出错"); 217 e.printStackTrace(); 218 } 219 folderList.removeFirst(); 220 folderList2.removeFirst(); 221 } 222 223 //14.复制一个文件夹下所有的文件夹到另一个文件夹下 224 //import java.io.*; 225 //import java.util.*; 226 File copyfolders=new File(str1); 227 File[] copyfoldersList=copyfolders.listFiles(); 228 for(int k=0;k
folderList=new ArrayList
(); 231 folderList.add(copyfoldersList[k].getPath()); 232 ArrayList
folderList2=new ArrayList
(); 233 folderList2.add(str2+"/"+copyfoldersList[k].getName()); 234 for(int j=0;j
folderList = new LinkedList
(); 277 folderList.add(str1); 278 LinkedList
folderList2 = new LinkedList
(); 279 folderList2.add(str2 + str1.substring(str1.lastIndexOf("\\"))); 280 while (folderList.size() > 0) { 281 (new File(folderList2.peek())).mkdirs(); // 如果文件夹不存在 则建立新文件夹 282 File folders = new File(folderList.peek()); 283 String[] file = folders.list(); 284 File temp = null; 285 try { 286 for (int i = 0; i < file.length; i++) { 287 if (folderList.peek().endsWith(File.separator)) { 288 temp = new File(folderList.peek() + File.separator + file[i]); 289 } else { 290 temp = new File(folderList.peek() + File.separator + file[i]); 291 } 292 if (temp.isFile()) { 293 FileInputStream input = new FileInputStream(temp); 294 FileOutputStream output = new FileOutputStream( 295 folderList2.peek() + File.separator + (temp.getName()).toString()); 296 byte[] b = new byte[5120]; 297 int len; 298 while ((len = input.read(b)) != -1) { 299 output.write(b, 0, len); 300 } 301 output.flush(); 302 output.close(); 303 input.close(); 304 if (!temp.delete()) 305 System.out.println("删除单个文件操作出错!"); 306 } 307 if (temp.isDirectory()) { // 如果是子文件夹 308 for (File f : temp.listFiles()) { 309 if (f.isDirectory()) { 310 folderList.add(f.getPath()); 311 folderList2.add(folderList2.peek() + File.separator + f.getName()); 312 } 313 } 314 } 315 } 316 } catch (Exception e) { 317 // System.out.println("复制整个文件夹内容操作出错"); 318 e.printStackTrace(); 319 } 320 folderList.removeFirst(); 321 folderList2.removeFirst(); 322 } 323 File f = new File(str1); 324 if (!f.delete()) { 325 for (File file : f.listFiles()) { 326 if (file.list().length == 0) { 327 System.out.println(file.getPath()); 328 file.delete(); 329 } 330 } 331 } 332 //16.移动一个文件夹下所有的文件夹到另一个目录下 333 //import java.io.*; 334 //import java.util.*; 335 File movefolders=new File(str1); 336 File[] movefoldersList=movefolders.listFiles(); 337 for(int k=0;k
folderList=new ArrayList
(); 340 folderList.add(movefoldersList[k].getPath()); 341 ArrayList
folderList2=new ArrayList
(); 342 folderList2.add(str2+"/"+movefoldersList[k].getName()); 343 for(int j=0;j
folderList=new ArrayList
(); 390 folderList.add(str1); 391 ArrayList
folderList2=new ArrayList
(); 392 folderList2.add(str2); 393 for(int j=0;j

 

二、Java文件读写操作代码

[来源]http://www.cnblogs.com/zhuocheng/archive/2011/12/12/2285290.html

一.获得控制台用户输入的信息

     public String getInputMessage() throws IOException...{
         System.out.println("请输入您的命令∶");
         byte buffer[]=new byte[1024];
         int count=System.in.read(buffer);
         char[] ch=new char[count-2];//最后两位为结束符,删去不要
         for(int i=0;i<count-2;i++)
             ch[i]=(char)buffer[i];
         String str=new String(ch);
         return str;
     }
     可以返回用户输入的信息,不足之处在于不支持中文输入,有待进一步改进。

     二.复制文件

     1.以文件流的方式复制文件
     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();
     }
     该方法经过测试,支持中文处理,并且可以复制多种类型,比如txt,xml,jpg,doc等多种格式

     三.写文件

     1.利用PrintStream写文件

     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();
         }
     }
     2.利用StringBuffer写文件
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("这是第"+i+"行:前面介绍的各种方法都不关用,为什么总是奇怪的问题 ");
             out.write(sb.toString().getBytes("utf-8"));
         }        
         out.close();
     }
     该方法可以设定使用何种编码,有效解决中文问题。
四.文件重命名
    
     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时,才有必要进行重命名
             File oldfile=new File(path+"/"+oldname);
             File newfile=new File(path+"/"+newname);
             if(newfile.exists())//若在该目录下已经有一个文件和新文件名相同,则不允许重命名
                 System.out.println(newname+"已经存在!");
             else...{
                 oldfile.renameTo(newfile);
             }
         }         
     }

  五.转移文件目录

     转移文件目录不等同于复制文件,复制文件是复制后两个目录都存在该文件,而转移文件目录则是转移后,只有新目录中存在该文件。
    
     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())...{//若在待转移目录下,已经存在待转移文件
                 if(cover)//覆盖
                     oldfile.renameTo(newfile);
                 else
                     System.out.println("在新目录下已经存在:"+filename);
             }
             else...{
                 oldfile.renameTo(newfile);
             }
         }       
     }
     六.读文件
     1.利用FileInputStream读取文件
    
     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,避免和上次读取的数据重复
         }
         return sb.toString();
     }
2.利用BufferedReader读取

     在IO操作,利用BufferedReader和BufferedWriter效率会更高一点

    
     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();
     }

     3.利用dom4j读取xml文件

    

     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;
     }
     七.创建文件(文件夹)

1.创建文件夹  
     public void createDir(String path)...{
         File dir=new File(path);
         if(!dir.exists())
             dir.mkdir();
     }
2.创建新文件
     public void createFile(String path,String filename) throws IOException...{
         File file=new File(path+"/"+filename);
         if(!file.exists())
             file.createNewFile();
     }
     八.删除文件(目录)
1.删除文件     
     public void delFile(String path,String filename)...{
         File file=new File(path+"/"+filename);
         if(file.exists()&&file.isFile())
             file.delete();
     }
2.删除目录
要利用File类的delete()方法删除目录时,必须保证该目录下没有文件或者子目录,否则删除失败,因此在实际应用中,我们要删除目录,必须利用递归删除该目录下的所有子目录和文件,然后再删除该目录。  
     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();
         }
     }

 

转载于:https://www.cnblogs.com/lilooo/p/4974706.html

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