Propertes文件的读取和保存(保留注释)

读取比较简单~~

保存的时候，如果使用默认的property.store()方法，会把所有的注释都忽略~

所以自己采用读取文件的方式，来实现保存property~

/**
	 * Update the key's value to new value ,and write back to the Configuration
	 * file
	 * 
	 * @param configFilePath
	 *            Configuration file
	 * @param key
	 *            the key
	 * @param value
	 *            the new value
	 */
	public static Boolean updateProperty(String configFilePath, String key, String value) {
		// Read File
		BufferedReader reader = null;
		try {
			reader = new BufferedReader(new FileReader(configFilePath));
		} catch (FileNotFoundException e) {
			Log.getInstance().fine("Can not find file: " + configFilePath + "."); //$NON-NLS-1$ //$NON-NLS-2$ 
		}
		StringBuilder builder = new StringBuilder();
		String tempLine;
		String tempValue;
		
		// Find the property and update
		try {
			while ((tempLine = reader.readLine()) != null) {
				if (tempLine.trim().startsWith(COMMENT_FALG)) {
					builder.append(tempLine).append(LINE_SEPARATOR);
					continue;
				}
				if (tempLine.contains(key)) {
					
					tempValue = tempLine.trim().substring(key.length());
					
					if (tempValue.trim().startsWith(EQUAL_FLAG)) {
						tempLine = key + EQUAL_FLAG + value; 
					}
				}			
				builder.append(tempLine).append(LINE_SEPARATOR);
			}
			reader.close();
		} catch (IOException e) {
			Log.getInstance().fine("Read  configuration file: " + configFilePath + " error."); //$NON-NLS-1$ //$NON-NLS-2$ 
			e.printStackTrace();
		}
		
		// Update File
		BufferedWriter writer = null;
		try {
			writer = new BufferedWriter(new FileWriter(configFilePath));
			writer.append(builder.toString());
			writer.close();
		} catch (IOException e) {
			Log.getInstance().fine("Update configuration file: " + configFilePath + " error."); //$NON-NLS-1$ //$NON-NLS-2$ 
		}
		return true;
	}
	/**
	 * Get value from configuration file by key
	 * 
	 * @param configFilePath
	 *            configuration file path
	 * 
	 * @param key
	 *            the key
	 * 
	 * @return the value
	 */
	public static String getProperty(String configFilePath, String key) {
		Properties prop = new Properties();
		try {
			prop.load(new FileInputStream(configFilePath));
		} catch (FileNotFoundException e) {
			Log.getInstance().fine("Can not find file: " + configFilePath + "."); //$NON-NLS-1$ //$NON-NLS-2$ 
		} catch (IOException e) {
			Log.getInstance().fine("Error read configuration file: " + configFilePath + " ."); //$NON-NLS-1$ //$NON-NLS-2$ 
		}
		return prop.getProperty(key);
	}