java 属性文件（配置文件）的操作

很久以前保存的网页，源地址不记得了，在我的环境中把代码敲了一遍。
配置文件叫做：ipConfig.properties，里面有两行内容：
ip=127.0.0.1
port=8080

package cn.treemp3.test;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Properties;

/**
 *
 * @author yangfusheng9
 */
public class PropertiesTest {
    private Properties properties;

    public PropertiesTest() {
        properties = new Properties();
    }
    public PropertiesTest(String file) {
        properties = new Properties();
        try {
            FileInputStream inputFile = new FileInputStream(file);
            properties.load(inputFile);
            inputFile.close();
        } catch (FileNotFoundException e) {
            System.out.println("读取属性文件失败！可能原因：文件路径错误或者文件不存在");
            e.printStackTrace();
        } catch (IOException e) {
            System.out.println("装载文件失败！");
            e.printStackTrace();
        }
    }
    public String getValue(String key) {
        if (properties.containsKey(key)) {
            String value = properties.getProperty(key);
            return value;
        } else {
            return "";
        }
    }
    public void clear() {
        properties.clear();
    }
    public void setValue(String key, String value) {
        properties.setProperty(key, value);
    }
    public void saveFile(String file, String description) {
        try {
            FileOutputStream outputFile = new FileOutputStream(file);
            properties.store(outputFile, description);
            outputFile.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        PropertiesTest test = new PropertiesTest("ipConfig.properties");
        String ip = test.getValue("ip");
        String port = test.getValue("port");
        System.out.println("ip: " + ip);
        System.out.println("port: " + port);
        test.setValue("host", "localhost");
        test.saveFile("save.properties", "test");
    }

}