Question

这是将哈希表写入.txt文件的代码！

public static void save(String filename, Map<String, String> hashtable) throws IOException {
    Properties prop = new Properties();
    prop.putAll(hashtable);
    FileOutputStream fos = new FileOutputStream(filename);
    try {
       prop.store(fos, prop);
    } finally {
       fos.close();
    }
}

我们如何从该文件中获取哈希表？感谢

Answer 1

以同样丑陋的方式：

@SuppressWarnings("unchecked")
public static Map<String, String> load(String filename) throws IOException {
    Properties prop = new Properties();
    FileInputStream fis = new FileInputStream(filename);
    try {
        prop.load(fis);
    } finally {
        fis.close();
    }
    return (Map) prop;
}

Answer 2

使用Properties.load()

代码示例：

public static Properties load(String filename) {
    FileReader reader = new FileReader(filename);
    Properties props = new Properties(); // The variable name must be used as props all along or must be properties
    try{
        props.load(reader);
    } finally {
        reader.close();
    }
    return props;
}

编辑：

如果你想要一张地图，请使用类似的东西。（toString是为了避免强制转换 - 如果您愿意，可以强制转换为String）

public static Map<String, String> load(String filename) {
    FileReader reader = new FileReader(filename);
    Properties props = new Properties();
    try {
        props.load(reader);
    } finally {
        reader.close();
    }
    Map<String, String> myMap = new HashMap<String, String>();
    for (Object key : props.keySet()) {
        myMap.put(key.toString(), props.get(key).toString());
    }
    return myMap;
}

如何从.txt文件中获取Map使用属性？

2 个答案: