java读取properties文件代码

private final static String SYS_TEMP_FILE = System  
            .getProperty("java.io.tmpdir") + "9884698793643198z.properties";  
    private static Map<String,String> fileNames = null;  

    /** 
     * get a file path from a system temp file. 
     *  
     * @param keyOfFileName 
     * @return 
     */  
    public static final String getAFilePathFromSysTempFile(String keyOfFileName) {  
        if (null == fileNames) {  
            fileNames = new HashMap<String,String>();  
            loadFilePathsFromSysTempFile();  
        }  
        String path = fileNames.get(keyOfFileName);  
        return null == path ? "" : path;  
    }  

    private static final boolean loadFilePathsFromSysTempFile() {  
        try {  
            if (!new File(SYS_TEMP_FILE).exists()) {  
                new File(SYS_TEMP_FILE).createNewFile();  
                return true;  
            }  
            Properties props = new Properties();  
            InputStream in = new BufferedInputStream(new FileInputStream(  
                    SYS_TEMP_FILE));  
            props.load(in);  
            Enumeration<?> en = props.propertyNames();  
            while (en.hasMoreElements()) {  
                String key = (String) en.nextElement();  
                String prop = props.getProperty(key);  
                fileNames.put(key,prop);  

            }  
            return true;  
        } catch (Exception e) {  
            e.printStackTrace();  
            return false;  
        }  
    }  

    /** 
     * save a file path to a system temp file. 
     *  
     * @param parameterName 
     * @param parameterValue 
     * @return 
     */  
    public static final int saveAFilePathToSysTempFile(String parameterName,String parameterValue) {  
        Properties prop = new Properties();  
        try {  
            InputStream fis = new FileInputStream(SYS_TEMP_FILE);  
            prop.load(fis);  

            OutputStream fos = new FileOutputStream(SYS_TEMP_FILE);  
            prop.setProperty(parameterName,parameterValue);  
            prop.store(fos,"Update '" + parameterName + "' value");  

            fileNames.put(parameterName,parameterValue);  
            return fileNames.size();  
        } catch (IOException e) {  
            e.printStackTrace();  
            return -1;  
        }  
    }