java - 如何保存最后一个 session 的变量值(程序退出)

Question

这个问题已经有答案了:

Saving user settings from GUI (1 个回答)

已关闭 8 年前。

如何在程序中保存变量的值，然后在下一个程序运行时重用它？我不想通过文件写入/读取来完成此操作。

Answer 1

使用Java Preferences API .

import java.util.prefs.*;

public class Example {
    // Preference key
    private static final String FRUIT = "fruit";

    public void savePreference(String favoriteFruit) {
        Preferences prefs = Preferences.userNodeForPackage(Example.class);

        prefs.put(FRUIT, favoriteFruit);
    }

    public String readPreference() {
        Preferences prefs = Preferences.userNodeForPackage(Example.class);

        return prefs.get(FRUIT, "default");
    }
}

数据是根据类的完全限定名称存储的，因此您的包名称和类名称是相关的。来自 documentation for the Preferences class :

This class allows applications to store and retrieve user and system preference and configuration data. This data is stored persistently in an implementation-dependent backing store. Typical implementations include flat files, OS-specific registries, directory servers and SQL databases. The user of this class needn't be concerned with details of the backing store.