java - Java：存储哈希图的理想文件格式？

Question

我需要将哈希图的数组列表保存到外部文件中。我可以对文本文件使用任何格式，因为程序设置为忽略文本文件（特别是任何带有.txt扩展名的文件）。哈希图非常简单，只是带有这些单词计数的单词。存储它的理想文件格式是什么？

Answer 1

你可以使用java.util.Properties.

Properties properties = new Properties();
properties.putAll(yourMap); // You could also just use Properties in first place.

try (OutputStream output = new FileOutputStream("/foo.properties")) {
    properties.store(output, null);
}

您可以稍后阅读

Properties properties = new Properties();

try (InputStream input = new FileInputStream("/foo.properties")) {
    properties.load(input);
}

// ... (Properties implements Map, you could just treat it like a Map)

也可以看看：

• Java 教程 - 基本类 - 属性

Answer 2

您可以使用序列化：

    ObjectOutputStream stream = null;
    try
    {
        File f = new File(filename);
        stream = new ObjectOutputStream(new FileOutputStream(f));
        stream.writeObject(your_arraylist);
    }
    catch (IOException e)
    {
        // Handle error
    }
    finally
    {
        if (stream != null)
        {
            try
            {
                stream.close();
            }
            catch (Exception e) {}
        }
    }

并在使用中阅读：

    ObjectInputStream stream = null;
    try
    {
        stream = new ObjectInputStream(new FileInputStream(f));
        your_arrayList = (your_arrayList type here)stream.readObject();
    }
    catch (Throwable t)
    {
        // Handle error
    }
    finally
    {
        if (stream != null)
        {
            try
            {
                stream.close();
            }
            catch (Exception e) {}
        }
    }