Java File 操作

 //1.创建文件夹     //import java.io.*;     File myFolderPath = new File(str1);     try {         if (!myFolderPath.exists()) {            myFolderPath.mkdir();         }     }     catch (Exception e) {         System.out.println("新建目录操作出错");         e.printStackTrace();     }      //2.创建文件     //import java.io.*;     File myFilePath = new File(str1);     try {         if (!myFilePath.exists()) {             myFilePath.createNewFile();         }         FileWriter resultFile = new FileWriter(myFilePath);         PrintWriter myFile = new PrintWriter(resultFile);         myFile.println(str2);         resultFile.close();     }     catch (Exception e) {         System.out.println("新建文件操作出错");         e.printStackTrace();     }      //3.删除文件     //import java.io.*;     File myDelFile = new File(str1);     try {         myDelFile.delete();     }     catch (Exception e) {         System.out.println("删除文件操作出错");         e.printStackTrace();     }      //4.删除文件夹     //import java.io.*;     File delFolderPath = new File(str1);     try {         delFolderPath.delete(); //删除空文件夹     }     catch (Exception e) {         System.out.println("删除文件夹操作出错");         e.printStackTrace();     }      //5.删除一个文件下夹所有的文件夹     //import java.io.*;     File delfile=new File(str1);     File[] files=delfile.listFiles();     for(int i=0;i<files.length;i++){         if(files[i].isDirectory()){             files[i].delete();         }     }       //6.清空文件夹     //import java.io.*;     File delfilefolder=new File(str1);     try {         if (!delfilefolder.exists()) {             delfilefolder.delete();         }         delfilefolder.mkdir();     }     catch (Exception e) {         System.out.println("清空目录操作出错");         e.printStackTrace();     }      //7.读取文件     //import java.io.*;     // 逐行读取数据     FileReader fr = new FileReader(str1);     BufferedReader br = new BufferedReader(fr);     String str2 = br.readLine();     while (str2 != null) {         str3         str2 = br.readLine();     }     br.close();     fr.close();      //8.写入文件     //import java.io.*;     // 将数据写入文件     try {         FileWriter fw = new FileWriter(str1);         fw.write(str2);         fw.flush();         fw.close();      } catch (IOException e) {         e.printStackTrace();     }     //9.写入随机文件     //import java.io.*;     try {         RandomAcessFile logFile=new RandomAcessFile(str1,"rw");         long lg=logFile.length();         logFile.seek(str2);         logFile.writeByte(str3);     }catch(IOException ioe){         System.out.println("无法写入文件："+ioe.getMessage());     }      //10.读取文件属性     //import java.io.*;     // 文件属性的取得     File f = new File(str1);     if (af.exists()) {         System.out.println(f.getName() + "的属性如下： 文件长度为：" + f.length());         System.out.println(f.isFile() ? "是文件" : "不是文件");         System.out.println(f.isDirectory() ? "是目录" : "不是目录");         System.out.println(f.canRead() ? "可读取" : "不");         System.out.println(f.canWrite() ? "是隐藏文件" : "");         System.out.println("文件夹的最后修改日期为：" + new Date(f.lastModified()));         } else {         System.out.println(f.getName() + "的属性如下：");         System.out.println(f.isFile() ? "是文件" : "不是文件");         System.out.println(f.isDirectory() ? "是目录" : "不是目录");         System.out.println(f.canRead() ? "可读取" : "不");         System.out.println(f.canWrite() ? "是隐藏文件" : "");         System.out.println("文件的最后修改日期为：" + new Date(f.lastModified()));     }     if(f.canRead()){         str2     }     if(f.canWrite()){         str3     }     //11.写入属性     //import java.io.*;     File filereadonly=new File(str1);     try {         boolean b=filereadonly.setReadOnly();     }     catch (Exception e) {         System.out.println("拒绝写访问："+e.printStackTrace());     }      //12.枚举一个文件夹中的所有文件     //import java.io.*;     //import java.util.*;     LinkedList<String> folderList = new LinkedList<String>();     folderList.add(str1);     while (folderList.size() > 0) {         File file = new File(folderList.peek());         folderList.removeLast();         File[] files = file.listFiles();         ArrayList<File> fileList = new ArrayList<File>();         for (int i = 0; i < files.length; i++) {             if (files[i].isDirectory()) {                 folderList.add(files[i].getPath());             } else {                 fileList.add(files[i]);             }         }         for (File f : fileList) {             str2=f.getAbsoluteFile();             str3         }     }     //13.复制文件夹      //import java.io.*;     //import java.util.*;     LinkedList<String> folderList = new LinkedList<String>();     folderList.add(str1);     LinkedList<String> folderList2 = new LinkedList<String>();     folderList2.add(str2+ str1.substring(str1.lastIndexOf("\\")));     while (folderList.size() > 0) {         (new File(folderList2.peek())).mkdirs(); // 如果文件夹不存在 则建立新文件夹         File folders = new File(folderList.peek());         String[] file = folders.list();         File temp = null;         try {             for (int i = 0; i < file.length; i++) {                 if (folderList.peek().endsWith(File.separator)) {                     temp = new File(folderList.peek() + File.separator                     + file[i]);                 } else {                     temp = new File(folderList.peek() + File.separator + file[i]);                 }                 if (temp.isFile()) {                     FileInputStream input = new FileInputStream(temp);                     FileOutputStream output = new FileOutputStream(                     folderList2.peek() + File.separator + (temp.getName()).toString());                     byte[] b = new byte[5120];                     int len;                     while ((len = input.read(b)) != -1) {                         output.write(b, 0, len);                     }                     output.flush();                     output.close();                     input.close();                 }                 if (temp.isDirectory()) {// 如果是子文件夹                     for (File f : temp.listFiles()) {                         if (f.isDirectory()) {                             folderList.add(f.getPath());                             folderList2.add(folderList2.peek()                             + File.separator + f.getName());                         }                     }                 }             }         } catch (Exception e) {         //System.out.println("复制整个文件夹内容操作出错");             e.printStackTrace();         }         folderList.removeFirst();         folderList2.removeFirst();     }     //14.复制一个文件夹下所有的文件夹到另一个文件夹下     //import java.io.*;     //import java.util.*;     File copyfolders=new File(str1);     File[] copyfoldersList=copyfolders.listFiles();     for(int k=0;k<copyfoldersList.length;k++){         if(copyfoldersList[k].isDirectory()){             ArrayList<String>folderList=new ArrayList<String>();             folderList.add(copyfoldersList[k].getPath());             ArrayList<String>folderList2=new ArrayList<String>();             folderList2.add(str2+"/"+copyfoldersList[k].getName());             for(int j=0;j<folderList.length;j++){                  (new File(folderList2.get(j))).mkdirs(); //如果文件夹不存在 则建立新文件夹                  File folders=new File(folderList.get(j));                  String[] file=folders.list();                  File temp=null;                  try {                      for (int i = 0; i < file.length; i++) {                          if(folderList.get(j).endsWith(File.separator)){                              temp=new File(folderList.get(j)+"/"+file[i]);                          } else {                              temp=new File(folderList.get(j)+"/"+File.separator+file[i]);                          }                          FileInputStream input = new FileInputStream(temp);                          if(temp.isFile()){                              FileInputStream input = new FileInputStream(temp);                              FileOutputStream output = new FileOutputStream(folderList2.get(j) + "/" + (temp.getName()).toString());                              byte[] b = new byte[5120];                              int len;                              while ( (len = input.read(b)) != -1) {                                  output.write(b, 0, len);                              }                              output.flush();                              output.close();                              input.close();                          }                          if(temp.isDirectory()){//如果是子文件夹                              folderList.add(folderList.get(j)+"/"+file[i]);                              folderList2.add(folderList2.get(j)+"/"+file[i]);                          }                      }                  }                  catch (Exception e) {                      System.out.println("复制整个文件夹内容操作出错");                      e.printStackTrace();                  }             }         }     }     //15.移动文件夹     //import java.io.*;     //import java.util.*;     LinkedList<String> folderList = new LinkedList<String>();     folderList.add(str1);     LinkedList<String> folderList2 = new LinkedList<String>();     folderList2.add(str2 + str1.substring(str1.lastIndexOf("\\")));     while (folderList.size() > 0) {         (new File(folderList2.peek())).mkdirs(); // 如果文件夹不存在 则建立新文件夹         File folders = new File(folderList.peek());         String[] file = folders.list();         File temp = null;         try {             for (int i = 0; i < file.length; i++) {                 if (folderList.peek().endsWith(File.separator)) {                     temp = new File(folderList.peek() + File.separator + file[i]);                 } else {                     temp = new File(folderList.peek() + File.separator + file[i]);                 }                 if (temp.isFile()) {                     FileInputStream input = new FileInputStream(temp);                     FileOutputStream output = new FileOutputStream(                     folderList2.peek() + File.separator + (temp.getName()).toString());                     byte[] b = new byte[5120];                     int len;                     while ((len = input.read(b)) != -1) {                         output.write(b, 0, len);                     }                     output.flush();                     output.close();                     input.close();                     if (!temp.delete())                     System.out.println("删除单个文件操作出错!");                 }                 if (temp.isDirectory()) {// 如果是子文件夹                     for (File f : temp.listFiles()) {                         if (f.isDirectory()) {                             folderList.add(f.getPath());                             folderList2.add(folderList2.peek() + File.separator + f.getName());                         }                     }                 }             }         } catch (Exception e) {             // System.out.println("复制整个文件夹内容操作出错");             e.printStackTrace();         }         folderList.removeFirst();         folderList2.removeFirst();     }     File f = new File(str1);     if (!f.delete()) {         for (File file : f.listFiles()) {             if (file.list().length == 0) {                 System.out.println(file.getPath());                 file.delete();             }         }     }     //16.移动一个文件夹下所有的文件夹到另一个目录下     //import java.io.*;     //import java.util.*;     File movefolders=new File(str1);     File[] movefoldersList=movefolders.listFiles();     for(int k=0;k<movefoldersList.length;k++){         if(movefoldersList[k].isDirectory()){             ArrayList<String>folderList=new ArrayList<String>();             folderList.add(movefoldersList[k].getPath());             ArrayList<String>folderList2=new ArrayList<String>();             folderList2.add(str2+"/"+movefoldersList[k].getName());             for(int j=0;j<folderList.length;j++){                  (new File(folderList2.get(j))).mkdirs(); //如果文件夹不存在 则建立新文件夹                  File folders=new File(folderList.get(j));                  String[] file=folders.list();                  File temp=null;                  try {                      for (int i = 0; i < file.length; i++) {                          if(folderList.get(j).endsWith(File.separator)){                              temp=new File(folderList.get(j)+"/"+file[i]);                          }                          else{                              temp=new File(folderList.get(j)+"/"+File.separator+file[i]);                          }                          FileInputStream input = new FileInputStream(temp);                          if(temp.isFile()){                              FileInputStream input = new FileInputStream(temp);                              FileOutputStream output = new FileOutputStream(folderList2.get(j) + "/" + (temp.getName()).toString());                              byte[] b = new byte[5120];                              int len;                              while ( (len = input.read(b)) != -1) {                                  output.write(b, 0, len);                              }                              output.flush();                              output.close();                              input.close();                              temp.delete();                          }                          if(temp.isDirectory()){//如果是子文件夹                              folderList.add(folderList.get(j)+"/"+file[i]);                              folderList2.add(folderList2.get(j)+"/"+file[i]);                          }                      }                  }                  catch (Exception e) {                      System.out.println("复制整个文件夹内容操作出错");                      e.printStackTrace();                  }             }             movefoldersList[k].delete();         }     }     //17.以一个文件夹的框架在另一个目录创建文件夹和空文件     //import java.io.*;     //import java.util.*;     boolean b=false;//不创建空文件     ArrayList<String>folderList=new ArrayList<String>();     folderList.add(str1);     ArrayList<String>folderList2=new ArrayList<String>();     folderList2.add(str2);     for(int j=0;j<folderList.length;j++){         (new File(folderList2.get(j))).mkdirs(); //如果文件夹不存在 则建立新文件夹         File folders=new File(folderList.get(j));         String[] file=folders.list();         File temp=null;         try {             for (int i = 0; i < file.length; i++) {                 if(folderList.get(j).endsWith(File.separator)){                     temp=new File(folderList.get(j)+"/"+file[i]);                 }                 else{                     temp=new File(folderList.get(j)+"/"+File.separator+file[i]);                 }                 FileInputStream input = new FileInputStream(temp);                 if(temp.isFile()){                     if (b) temp.createNewFile();                 }                 if(temp.isDirectory()){//如果是子文件夹                     folderList.add(folderList.get(j)+"/"+file[i]);                     folderList2.add(folderList2.get(j)+"/"+file[i]);                 }             }         }         catch (Exception e) {             System.out.println("复制整个文件夹内容操作出错");             e.printStackTrace();         }     }     //18.复制文件     //import java.io.*;      int bytesum = 0;      int byteread = 0;      File oldfile = new File(str1);      try {      if (oldfile.exists()) { //文件存在时      FileInputStream inStream = new FileInputStream(oldfile); //读入原文件      FileOutputStream fs = new FileOutputStream(new File(str2,oldfile.getName()));      byte[] buffer = new byte[5120];      int length;      while ( (byteread = inStream.read(buffer)) != -1) {      bytesum += byteread; //字节数 文件大小      System.out.println(bytesum);      fs.write(buffer, 0, byteread);      }      inStream.close();      }      }      catch (Exception e) {      System.out.println("复制单个文件操作出错");      e.printStackTrace();      }      //19.复制一个文件夹下所有的文件到另一个目录     //import java.io.*;     File copyfiles=new File(str1);     File[] files=copyfiles.listFiles();     for(int i=0;i<files.length;i++){         if(!files[i].isDirectory()){             int bytesum = 0;             int byteread = 0;             try {                 InputStream inStream = new FileInputStream(files[i]); //读入原文件                 FileOutputStream fs = new FileOutputStream(new File(str2,files[i].getName());                 byte[] buffer = new byte[5120];                 int length;                 while ( (byteread = inStream.read(buffer)) != -1) {                     bytesum += byteread; //字节数 文件大小                     System.out.println(bytesum);                     fs.write(buffer, 0, byteread);                 }                 inStream.close();             } catch (Exception e) {                 System.out.println("复制单个文件操作出错");                 e.printStackTrace();             }         }     }      //20.提取扩展名     String str2=str1.substring(str1.lastIndexOf(".")+1);