java核心编程之文件过滤类FileFilter和FilenameFilter

本文实例为大家分享了文件过滤类filefilter和filenamefilter，供大家参考，具体内容如下

1.filefilter

package test;

import java.io.file;
import java.io.filefilter;

public class filefiltertest implements filefilter {
  
  
  private string extension;
  
  public filefiltertest(string extension) {

    this.extension = extension;
  }
  /**
   * 
   */
  @override
  public boolean accept(file pathname) {
      
    if(pathname.isdirectory()){
      return false;
    }
    
    string name = pathname.getname();
    int num = name.lastindexof(".");
    if(num == -1){
      return false;
    }
    if(name.length()-1 == num){
      return false;
    } else {
    
      return extension.equals(name.substring(num+1));
    }
  }
  
  
  public static void main(string[] args) {
    
    file path = new file("e:\\书籍\\java 编程");
    //获得过滤对象
    filefiltertest ft = new filefiltertest("pdf");
    
    file[] files = path.listfiles(ft);
    
    for (int i = 0; i < files.length; i++) {
      system.out.println(files[i].getabsolutepath());
    } 
    
  }

}

2.filenamefilter

package test;

import java.io.file;
import java.io.filenamefilter;

public class filenamefiltertest implements filenamefilter {
  
  //判断图片是否格式是否是 gif
  private boolean isgif(string filename){
    if(filename.tolowercase().endswith(".gif")){
      return true;
    } else {
      return false;
    }
    
  }
  //判断图片是否格式是否是 jpg
  private boolean isjpg(string filename){
    if(filename.tolowercase().endswith(".jpg")){
      return true;
    } else {
      return false;
    }
    
  }
  //判断图片是否格式是否是 png
  private boolean ispng(string filename){
    if(filename.tolowercase().endswith(".png")){
      return true;
    } else {
      return false;
    }
    
  }
  
  

  @override
  public boolean accept(file dir, string name) {
    return (isgif(name)||isjpg(name)||ispng(name));
  }
  
  public static void main(string[] args) {
    file path = new file("c:\\img");
    //获得过滤对象
    filenamefiltertest ft = new filenamefiltertest();
    
    file[] f = path.listfiles(ft);
    
    for (int i = 0; i < f.length; i++) {
      file file = f[i];
      
      system.out.println(file.getabsolutepath());
      
    }
  }

}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。