Java文件操作大全

//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);