DouKaku?

import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.util.Properties;


public class Sample186 {
    private static final Properties defaultProperties_ = new Properties();
    static {
        defaultProperties_.setProperty("item.name", "nothing");
        defaultProperties_.setProperty("item.cost", "0");
    }


    private final Properties properties_ = new Properties(defaultProperties_);

    public Sample186(InputStream stream) throws IOException {
        properties_.load(stream);
    }
    public Sample186(Reader reader) throws IOException {
        properties_.load(reader);
    }

    public String get(String key) {
        return properties_.getProperty(key);
    }
    public int getInteger(String key) {
        try {
            return Integer.parseInt(get(key));
        } catch (NumberFormatException ex) {
            ex.printStackTrace();
            return 0;
        }
    }
    public long getLong(String key) {
        try {
            return Long.parseLong(get(key));
        } catch (NumberFormatException ex) {
            ex.printStackTrace();
            return 0L;
        }
    }
    public double getDouble(String key) {
        try {
            return Double.parseDouble(get(key));
        } catch (NumberFormatException ex) {
            ex.printStackTrace();
            return 0.0;
        }
    }


    public static void main(String[] args) {
        try {
            Sample186 apple = new Sample186(new FileInputStream("ShowPrice.properties"));
            System.out.println(getPrice(apple));
            Sample186 orange = new Sample186(new FileInputStream("ShowPrice2.properties"));
            System.out.println(getPrice(orange));
            Sample186 nothing = new Sample186(new FileInputStream("ShowPrice3.properties"));
            System.out.println(getPrice(nothing));
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }
    private static String getPrice(Sample186 sample186) {
        return String.format("「%s」は%d円（税込み）", sample186.get("item.name"), (int)(sample186.getInteger("item.cost") * 1.05));
    }
}