文件过滤

package fileFilter;


import java.io.File;
import java.io.FileFilter;
/**
* 按照文件对象过滤
* @author wxg1022
*
*/
public class ExtensionFile implements FileFilter {

private String extension;

public ExtensionFile(String extension) {
this.extension = extension;
}


@Override
public boolean accept(File file) {
// TODO Auto-generated method stub
if(file.isDirectory()){
return false;
}
String name=file.getName();
int index=name.lastIndexOf(".");
if(index==-1){//没有扩展名返回false
return false;
}else if(index==name.length()-1){////最后一位是.
return false;
}else{//如果扩展名同则返回true
return this.extension.equals(name.substring(index+1));
}
}



/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
File file=new File("D:/");
ExtensionFile filter=new ExtensionFile("txt");//创建一个txt过滤器
File[] files=file.listFiles(filter);
for(int i=0;i<files.length;i++){
System.out.println(files[i].getAbsolutePath());
}
}

}

----------------------------------------

package fileFilter;

import java.io.File;
import java.io.FilenameFilter;

/**
* 按照文件目录和文件名来过滤
* @author wxg1022
*
*/
public class ImageFilter implements FilenameFilter {

@Override
public boolean accept(File dir, String filename) {
// TODO Auto-generated method stub
System.out.println(dir.getAbsolutePath()+"-"+filename);

if(filename.toLowerCase().endsWith(".gif")){
return true;
}else if(filename.toLowerCase().endsWith(".jpg")){
return true;
}else if(filename.toLowerCase().endsWith(".bmp")){
return true;
}else if(filename.toLowerCase().endsWith(".png")){
return true;
}

return false;
}

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
File file=new File("D:/");
ImageFilter imgfilter=new ImageFilter();//创建一个图片过滤器
File[] imgfiles=file.listFiles(imgfilter);
for(int i=0;i<imgfiles.length;i++){
System.out.println(imgfiles[i].getAbsolutePath());
}
}

}