获取某个类型文件

package File;

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

public class FileNameSelector implements FilenameFilter {
    String extension = ".";

    public FileNameSelector(String fileExtensionNoDot) {
        extension += fileExtensionNoDot;
    }

    @Override
    public boolean accept(File dir, String name) {
        return name.endsWith(extension);
    }

    public static void main(String[] args) {
        File directory = new File("E:\\");
        // 列出所有文件
        File[] files = directory.listFiles();
        System.out.println("\n目录" + directory.getName() + "下的所有文件");
        for (File file : files) {
            System.out.print("  " + file.getName());
        }
        // 列出所有.txt文件
        File[] txtFiles = directory.listFiles(new FileNameSelector("txt"));
        System.out.println("\n目录" + directory.getName() + "下的.txt文件");
        for (File file : txtFiles) {
            System.out.print("  " + file.getName());
        }

        // 列出所有.java文件
        File[] javaFiles = directory.listFiles(new FileNameSelector("java"));
        System.out.println("\n目录" + directory.getName() + "下的.java文件");
        for (File file : javaFiles) {
            System.out.print("  " + file.getName());
        }
    }
}