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);