FilenameFilter过滤文件名

前言：

　　文件IO是程序设计语言的一个特点，本文将针对Java的File文件名过滤进行测试。

测试目录截图：

测试结果：

data.txt
output-.txt
output-.txt
output-d.txt
people-id.txt
qqmusic_cn_seed.txt
text-a20.txt
--- finish ----

---

版本一：接口继承

package com.yeezhao.common.io.v1;

import java.io.File;
import java.io.FilenameFilter;
import java.util.regex.Pattern;

public class MyFilenameFilter implements FilenameFilter {
    final static String REGEX = ".*\\.txt";

    @Override
    public boolean accept(File dir, String name) {
        return Pattern.matches(REGEX, name);
    }

}

package com.yeezhao.common.io.v1;

import java.io.File;
import java.util.Arrays;

public class FilenameFilterV1 {
    public static void main(String[] args)  throws Exception{
        System.out.println("--- start ----");
        File file = new File("c://test");
        String[] list = file.list(new MyFilenameFilter());
        Arrays.sort(list, String.CASE_INSENSITIVE_ORDER); //忽略字符串大小写进行字典排序
        for(String l:list){
            System.out.println(l);
        }
        System.out.println("--- finish ----");
    }
}

版本二：内部类初始化内部对象属性

package com.yeezhao.common.io.v2;

import java.io.File;
import java.io.FilenameFilter;
import java.util.Arrays;
import java.util.regex.Pattern;

public class FilenameFilterV2 {
    private static String REGEX =".*\\.txt";
    private static FilenameFilter filter = new FilenameFilter() {

        @Override
        public boolean accept(File dir, String name) {
            return Pattern.matches(REGEX, name);
        }
    };

    public static void main(String[] args) throws Exception {
        File file = new File("c://test");
        String[] list = file.list(filter);
        Arrays.sort(list, String.CASE_INSENSITIVE_ORDER);  //忽略字符串大小写进行字典排序
        for (String l : list) {
            System.out.println(l);
        }
        System.out.println("--- finish ----");

    }
}

版本三：内部类直接调用方法

package com.yeezhao.common.io.v3;

import java.io.File;
import java.io.FilenameFilter;
import java.util.Arrays;
import java.util.regex.Pattern;

public class FilenameFilterV3 {
    private static String REGEX =".*\\.txt";
    public static void main(String[] args) {
        File file = new File("c://test/");
        String[] list = file.list(new FilenameFilter() {

            @Override
            public boolean accept(File dir, String name) {
                return Pattern.matches(REGEX, name);
            }
        });
        Arrays.sort(list, String.CASE_INSENSITIVE_ORDER);  //忽略字符串大小写进行字典排序
        for (String l : list) {
            System.out.println(l);
        }
        System.out.println("--- finish ----");
    }
}

附：File对象的list()方法

后语：

   Java.io涉及相当多的工具类，后续在研究之余希望能上手java.nio的一些内容并进行对比为是！