import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.util.Properties;

public class Main {

    private static Main main = new Main();

    private Main(){}

    public static Main getMain() {

        return main;

    }

    public static Properties prop = null;

    // 静态加载配置文件

    static {

         prop = new Properties();

        ClassLoader classLoader = Main.class.getClassLoader();

        InputStream inputStream = classLoader.getResourceAsStream("config.properties");

        try {

            prop.load(inputStream);

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

    // 给properties中设置值

    public static void modifyConfig(String key, String value) {

        try {

            // 从输入流中读取属性列表（键和元素对）

            prop.setProperty(key, value);

            String path = Main.class.getResource("/config.properties").getPath();

            FileOutputStream outputFile = new FileOutputStream(path);

            prop.store(outputFile, "modify");

            outputFile.close();

            outputFile.flush();

        } catch (Exception e) {

            e.printStackTrace();

        }

    }

    // 通过key获取值

    public static String getValueByKey(String key) {

        if(prop.get(key)!=null) {

            return (String) prop.get(key);

        }

        return null;

    }

}