文件名过滤器FilenameFilter的用法

Posted 2020-09-28 头痛不头痛

Java.io.FilenameFilter是文件名过滤器，用来过滤不符合规格的文件名，并返回合格的文件；

实例1，匹配指定字符结尾的文件

package cn.test;

import java.io.File;
import java.io.FilenameFilter;
import org.junit.Test;

public class Demo4  {
	@Test
	public void test1(){
		File file = new File("D:/Temp");
		FilterBysuffix filter = new FilterBysuffix(".txt");
		String[] files = file.list(filter);
		for (String fileName : files){
			System.out.println(fileName);
		}
	}
}


 class FilterBysuffix implements FilenameFilter{
	private String suffix;
	public FilterBysuffix(String suffix){
		this.suffix=suffix;
	}
	@Override
	public boolean accept(File dir, String name) {
		return name.endsWith(suffix);
	}
}

　　结果：

实例2，正则匹配文件

public class Test1 {
	
	@Test
	public void demo1() throws IOException{
		File file = new File("D:/tmp");
		FilterByMatches filterByMatches = new FilterByMatches(".*txt$");
		String[] files = file.list(filterByMatches);
		for(String f : files){
			System.out.println(f);
		}
	}
}

class FilterByMatches implements FilenameFilter{
    private String suffix;
    public FilterByMatches(String suffix){
        this.suffix=suffix;
    }
    public boolean accept(File dir, String name) {
        return name.matches(suffix);
    }
}

　　结果：