使用java系统属性user.dir读取配置文件

适用于windows和linux服务器读取配置文件

import java.io.File; import java.io.FileInputStream; import java.io.IOException; import java.util.Properties;

import org.apache.log4j.Logger;

public final class PropertyUtil { private static Logger LOG = Logger.getLogger(PropertyUtil.class);

// 配置文件
private static Properties demoProps = new Properties();
// 单例模式
private static PropertyUtil instance = null;

private PropertyUtil() {
	// user.dir为应用目录
	String filePath = System.getProperty("user.dir") + File.separator
			+ "WEB-INF" + File.separator + "classes" + File.separator
			+ "resources" + File.separator;
	LOG.info(filePath);
	try {
		File demoFile = new File(filePath + "demo.properties");

		if (httpFile.exists()) {
			demoProps.load(new FileInputStream(filePath
					+ "demo.properties"));
		}

	} catch (IOException e) {
		LOG.info("The Exception occured.", e);
	}
}

public synchronized static PropertyUtil getInstance() {
	if (null == instance) {
		instance = new PropertyUtil();
	}

	return instance;
}

/**
 * 获取参数值
 * 
 * @param key
 *            properites的key值
 * @param defValue
 *            默认值
 * @return
 */
public String getValues(String key, String defValue) {
	String rtValue = null;

	if (null == key) {
		LOG.error("key is null");
	} else {
		rtValue = getPropertiesValue(key);
	}

	if (null == rtValue) {
		LOG.warn("PropertyUtil.getValues return null, key is " + key);
		rtValue = defValue;
	}

	LOG.info("PropertyUtil.getValues: key is " + key + "; Value is "
			+ rtValue);

	return rtValue;
}

/**
 * 根据key值获取server.properties的值
 * 
 * @param key
 * @return
 */
private String getPropertiesValue(String key) {
	String rtValue = demoProps.getProperty(key);
	
	return rtValue;
}

}