Java文件处理类详解编程语言

包含一些对文件的基本操作。 
import java.io.*; 
import java.util.ArrayList; 
import java.util.List; 
public class fileTest { 
static int countFiles=0; 
static int countFolders=0; 
public static void  createFile(String filepath) 
{ 
File file=new File(filepath); 
if(file.exists()) 
{ 
System.out.println("目标文件已经存在!"); 
return; 
} 
if(filepath.endsWith(File.separator)) 
{ 
System.out.println("目标文件不能为目录!"); 
return; 
} 
try { 
if(file.createNewFile()) 
System.out.println("文件创建成功!"); 
else 
{ 
System.out.println("文件创建失败!"); 
return; 
} 
} catch (IOException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
} 
} 
public static void createDir(String dirname) 
{ 
if(!dirname.endsWith(File.separator)) 
dirname=dirname+File.separator; 
File dir=new File(dirname); 
if(dir.exists()) 
{ 
System.out.println("目录已存在!"); 
return; 
} 
if(dir.mkdirs()) 
System.out.println("目录创建成功!"); 
else 
{ 
System.out.println("目录创建失败!"); 
return; 
} 
} 
public static boolean checkDirExist(String dirname) 
{ 
File file=new File(dirname); 
if(file.exists()) 
{ 
if(file.isDirectory()) 
return true; 
} 
return false; 
} 
public static File[] getDirFiles(String dirname) 
{ 
File[] result=null; 
File fileDir = new File(dirname); 
if (!fileDir.exists())  
{ 
System.out.println("文件夹不存在"); 
return null; 
} 
else 
{ 
if (!fileDir.isDirectory())  
{ 
fileDir = new File(fileDir.getParent()); 
} 
result = fileDir.listFiles(); 
} 
return result; 
} 
public static void deleteFiles(String filename) 
{ 
File file=new File(filename); 
if(!file.exists()) 
{ 
System.out.println("文件不存在!"); 
return; 
} 
if(file.delete()) 
{ 
System.out.println(filename+"文件删除成功!"); 
} 
} 
public static void deleteDirs(String dirname) 
{ 
if(!dirname.endsWith(File.separator)) 
dirname=dirname+File.separator; 
File dirn=new File(dirname); 
if(!dirn.exists()) 
{ 
System.out.println("文件目录不存在!"); 
return; 
} 
File[] files=dirn.listFiles(); 
for(int i=0;i<files.length;i++) 
{ 
if(files[i].isFile()) 
{ 
deleteFiles(files[i].getAbsolutePath()); 
} 
else 
deleteDirs(files[i].getAbsolutePath()); 
} 
if(dirn.delete()) 
{ 
System.out.println("目录删除成功!"); 
} 
} 
public static void searchFiles(String dirname,String filename) 
{ 
if(!dirname.endsWith(File.separator)) 
dirname=dirname+File.separator; 
File dir=new File(dirname); 
if(!dir.exists()) 
{ 
System.out.println("该文件夹不存在"); 
return; 
} 
File[] files=dir.listFiles(); 
for(int i=0;i<files.length;i++) 
{ 
if(files[i].isFile()) 
{ 
if(files[i].getName().equals(filename)) 
System.out.println("文件路径为:"+files[i].getAbsolutePath()); 
} 
else 
{ 
searchFiles(files[i].getAbsolutePath(),filename); 
} 
} 
} 
public static File[] searchFile(File folder,final String keyWord) 
{     
File[] subFolders=folder.listFiles(new FileFilter() 
{ 
public boolean accept(File pathname) 
{ 
if(pathname.isFile()) 
countFiles++; 
else 
countFolders++; 
if(pathname.isDirectory()||(pathname.isFile()&&pathname.getName().contains(keyWord))) 
return true; 
return false; 
} 
}); 
List<File> result=new ArrayList<File>(); 
for(int i=0;i<subFolders.length;i++) 
{ 
if(subFolders[i].isFile()) 
result.add(subFolders[i]); 
else 
{ 
File[] foldResult=searchFile(subFolders[i],keyWord); 
for(int j=0;j<foldResult.length;j++) 
result.add(foldResult[j]); 
} 
} 
File files[]=new File[result.size()]; 
result.toArray(files); 
return files; 
} 
public static void copyFileToFile(File tofile,File fromfile) 
{ 
if(tofile.exists()) 
{ 
System.out.println("文件已经存在!"); 
return; 
}  
else 
{ 
try { 
tofile.createNewFile(); 
} catch (IOException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
} 
} 
System.out.println("复制文件从"+fromfile.getAbsolutePath()+"到"+tofile.getAbsolutePath()); 
try { 
InputStream is=new FileInputStream(fromfile); 
FileOutputStream fos=new FileOutputStream(tofile); 
byte []buffer=new byte[1024]; 
try { 
while(is.read(buffer)!=-1) 
fos.write(buffer); 
is.close(); 
fos.close(); 
} catch (IOException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
} 
} catch (FileNotFoundException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
} 
} 
/** 
* @param file 要复制的文件 
* @param dirname 文件复制到目标目录 
*/ 
public static void copyFileToDir(File file,String dirname) 
{ 
createDir(dirname); 
String filename=dirname+"/"+file.getName(); 
File nfile=new File(filename); 
copyFileToFile(nfile,file); 
} 
public static void copyDirToDir(String todir,String fromdir) 
{ 
File []f=getDirFiles(fromdir); 
for(int i=0;i<f.length;i++) 
{ 
if(f[i].isFile()) 
copyFileToDir(f[i],todir); 
else 
copyDirToDir(todir+"/"+f[i].getName(),fromdir+"/"+f[i].getName()); 
} 
System.out.println(fromdir+"复制到文件夹"+todir+"复制完成!"); 
} 
/** 
* @param args 
* @throws IOException  
*/ 
public static byte[] readFilebyByte(String filename) throws IOException 
{ 
byte[] result = null; 
File file = new File(filename); 
if (file.exists() && file.isFile() && file.length() > 0)  
{ 
result = new byte[(int) file.length()]; 
FileInputStream inStream = new FileInputStream(filename); 
inStream.read(result); 
inStream.close(); 
} 
return result; 
} 
public static void readFilebyLine(String filename) throws IOException 
{ 
File file=new File(filename); 
BufferedReader reader=null; 
System.out.println("以行为单位读取数据,一次读取一行:"); 
try { 
reader=new BufferedReader(new FileReader(file)); 
String temp=null; 
int line=1; 
while((temp=reader.readLine())!=null) 
{ 
System.out.println("line"+line+":"+temp); 
line++; 
} 
reader.close(); 
} catch (FileNotFoundException e) { 
// TODO Auto-generated catch block 
e.printStackTrace(); 
} 
} 
public static void writeFilebyByte(String filename) throws IOException 
{ 
String content="fsfni ds dw wod"; 
File file=new File(filename); 
OutputStream out=null; 
System.out.println("以字节为单位写入文件:"+content); 
out=new FileOutputStream(file); 
byte []bytes=content.getBytes(); 
out.write(bytes); 
out.close(); 
} 
public static void writeFilebyChar(String filename) throws IOException 
{ 
String content="fsfni ds dw wod"; 
File file=new File(filename); 
Writer writer=null; 
System.out.println("以字符为单位写入文件:"+content); 
writer=new OutputStreamWriter(new FileOutputStream(file)); 
writer.write(content); 
writer.close(); 
} 
public static void writeFilebyLine(String filename) throws IOException 
{ 
String content="fsfni ds dw wod"; 
File file=new File(filename); 
PrintWriter writer=null; 
System.out.println("以行为单位写入文件:"+content); 
writer=new PrintWriter(new FileOutputStream(file)); 
writer.println(content); 
writer.print(2355); 
writer.flush(); 
writer.close(); 
} 
public static void addContent1(String filename) throws IOException 
{ 
FileWriter writer=new FileWriter(filename,true); 
String content="this is a nice man,so you should get it"; 
writer.write(content); 
writer.close(); 
} 
public static void addContent2(String filename) throws IOException 
{ 
RandomAccessFile rfile=new RandomAccessFile(filename, "rw"); 
long filelength=rfile.length(); 
rfile.seek(filelength); 
String content="hello world"; 
rfile.write(content.getBytes("gb2312")); 
rfile.close(); 
} 
/** 
* @param args 
* @throws IOException  
*/ 
public static void main(String[] args) throws IOException { 
// TODO Auto-generated method stub 
String dirname="c:/cc/"; 
String todir="c:/dd/"; 
String tdir="c:/ee/"; 
String fn="c:/cc/c.txt"; 
String filename="ww.txt"; 
File folder=new File("c:/cc/"); 
String keyword="ww"; 
//readFilebyLine(fn); 
writeFilebyLine(fn); 
addContent1(fn); 
addContent2(fn); 
//File fromfile=new File("c:/cc/c.txt"); 
//File tofile=new File("e:/ccc.txt"); 
//byte[] fb=readFilebyByte(fn); 
//for(int i=0;i<fb.length;i++) 
// System.out.println((char)fb[i]); 
//System.out.println(fb.toString()); 
//copyFile(tofile,fromfile); 
//copyFileToDir(fromfile,todir); 
//copyDirToDir(tdir,dirname); 
//File[] f=searchFile(folder,keyword); 
//createDir(dirname); 
//deleteDirs(dirname); 
//searchFiles(dirname, filename); 
//File[] f=getDirFiles(dirname); 
//for(int i=0;i<f.length;i++) 
{ 
// System.out.println(f[i].getAbsolutePath()); 
} 
} 
}