古今東西java.langの判定プログラムを愚直に作ってみた

KokonTouzai.java

package game;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class KokonTouzai {

    public static void main(String[] args) throws IOException{
        KokonTouzai kokonTouzai = KokonTouzai.newInstance();
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String name = null;
        while (!"exit".equals(name)) {
            System.out.print("input ClassName-> ");
            name = reader.readLine();
            System.out.println("result:" + kokonTouzai.hasName(name));
        }
    }

    private String packageName;

    private KokonTouzai() { }

    public static KokonTouzai newInstance() {
        KokonTouzai result = new KokonTouzai();
        result.packageName = "java.lang";
        return result;
    }

    public Boolean hasName(String className) {
        String name = packageName + "." + className;
        try {
            Class.forName(name);
            return true;
        } catch (ClassNotFoundException e) {
            return false;
        }
    }
}