파일의 이름과 확장자 분리 / How to get name and extension of a file in java

파일의 이름과 확장자 분리 / How to get name and extension of a file in java

 

package test;

public class Test {

    public static void main(String[] args) {

        String file = "abcdef.pdf";
        int lastIndex = file.lastIndexOf(".");

        String fileName = file.substring(0, lastIndex);
        String extension = file.substring(lastIndex + 1);

        System.out.println("file name : " + fileName);
        System.out.println("file extension  : " + extension);
    }
}

 

package test;

import java.util.Optional;

public class Test {

    public static void main(String[] args) {

        String file = "abcdef.pdf";

        Optional<String> fileName = getFileNameByStringHandling(file);
        System.out.println("file name : " + fileName.get());

        Optional<String> extension = getExtensionByStringHandling(file);
        System.out.println("file extension  : " + extension.get());
    }

    public static Optional<String> getFileNameByStringHandling(String filename) {
        return Optional.ofNullable(filename).filter(f -> f.contains("."))
                .map(f -> f.substring(0, filename.lastIndexOf(".")));
    }

    public static Optional<String> getExtensionByStringHandling(String filename) {
        return Optional.ofNullable(filename).filter(f -> f.contains("."))
                .map(f -> f.substring(filename.lastIndexOf(".") + 1));
    }
}