java操作.properties文件

[java]代码库

import java.io.BufferedInputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Enumeration;
import java.util.Properties;

/**
 * java操作.properties文件
 * 
 */
public class Test {

	// 根据key读取value
	public static String readValue(String filePath, String key) {
		Properties props = new Properties();
		try {
			System.out.println("当前文件：" + filePath);
			InputStream in = new BufferedInputStream(new FileInputStream(
					filePath));
			props.load(in);
			String value = props.getProperty(key);
			System.out.println("根据key读取value：" + key + " = " + value);
			return value;
		} catch (Exception e) {
			e.printStackTrace();
			return null;
		}
	}

	// 读取properties的全部信息
	public static void readProperties(String filePath) {
		Properties props = new Properties();
		try {
			InputStream in = new BufferedInputStream(new FileInputStream(
					filePath));
			props.load(in);
			Enumeration<?> en = props.propertyNames();
			while (en.hasMoreElements()) {
				String key = (String) en.nextElement();
				String Property = props.getProperty(key);
				System.out.println("全部属性： " + key + " = " + Property);
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
	}

	// 写入properties信息
	public static void writeProperties(String filePath, String parameterName,
			String parameterValue) {
		Properties prop = new Properties();
		try {
			InputStream fis = new FileInputStream(filePath);

			// 从输入流中读取属性列表（键和元素对）
			prop.load(fis);
			OutputStream fos = new FileOutputStream(filePath);

			prop.setProperty(parameterName, parameterValue);
			prop.store(fos, "Update '" + parameterName + "' value");
		} catch (IOException e) {
			System.err.println("Visit " + filePath + " for updating "
					+ parameterName + " value error");
		}
	}

	public static void main(String[] args) {
		readValue("c:\\info.properties", "url_1"); // 根据key获取value

		writeProperties("c:\\info.properties", "url_1",
				"http://www.yuncode.net");
		writeProperties("c:\\info.properties", "url_2", "http://www.baidu.com");

		readProperties("c:\\info.properties"); // 读取全部属性
	}
}

[代码运行效果截图]