如何获取Windows系统中的剩余电池寿命？

我需要获取 Windows 系统中的剩余电池寿命。我该怎么做？

我猜你说的是笔记本电脑。标准 Java SE API 中不存在这样的 API。此信息仅在操作系统平台本机 API 中可用。你至少需要JNI https://docs.oracle.com/javase/8/docs/technotes/guides/jni/ or JNA https://github.com/java-native-access/jna （JavaWorld 文章） https://www.javaworld.com/article/2077828/open-source-java-projects-java-native-access.html能够与平台原生API进行通信。

在 Windows 中，您想连接SYSTEM_POWER_STATUS结构 https://learn.microsoft.com/en-us/windows/win32/api/winbase/ns-winbase-system_power_status。除其他外，它还提供BatteryLifePercent您可能感兴趣的财产。我在旧的 forums.sun.com 主题中找到了一个有用的基于 JNA 的代码片段，该主题目前不再可用。因此，这实际上归功于姓名不得公开的作者。

为了让它工作，首先下降jna.jar https://repo1.maven.org/maven2/net/java/dev/jna/jna/5.5.0/jna-5.5.0.jar在类路径中，然后将以下未修改的类复制到您的项目中：

package com.stackoverflow.q3434719;

import java.util.ArrayList;
import java.util.List;

import com.sun.jna.Native;
import com.sun.jna.Structure;
import com.sun.jna.win32.StdCallLibrary;

public interface Kernel32 extends StdCallLibrary {

    public Kernel32 INSTANCE = Native.load("Kernel32", Kernel32.class);

    /**
     * @see https://learn.microsoft.com/en-us/windows/win32/api/winbase/ns-winbase-system_power_status
     */
    public class SYSTEM_POWER_STATUS extends Structure {
        public byte ACLineStatus;
        public byte BatteryFlag;
        public byte BatteryLifePercent;
        public byte Reserved1;
        public int BatteryLifeTime;
        public int BatteryFullLifeTime;

        @Override
        protected List<String> getFieldOrder() {
            ArrayList<String> fields = new ArrayList<String>();
            fields.add("ACLineStatus");
            fields.add("BatteryFlag");
            fields.add("BatteryLifePercent");
            fields.add("Reserved1");
            fields.add("BatteryLifeTime");
            fields.add("BatteryFullLifeTime");
            return fields;
        }

        /**
         * The AC power status
         */
        public String getACLineStatusString() {
            switch (ACLineStatus) {
                case (0): return "Offline";
                case (1): return "Online";
                default: return "Unknown";
            }
        }

        /**
         * The battery charge status
         */
        public String getBatteryFlagString() {
            switch (BatteryFlag) {
                case (1): return "High, more than 66 percent";
                case (2): return "Low, less than 33 percent";
                case (4): return "Critical, less than five percent";
                case (8): return "Charging";
                case ((byte) 128): return "No system battery";
                default: return "Unknown";
            }
        }

        /**
         * The percentage of full battery charge remaining
         */
        public String getBatteryLifePercent() {
            return (BatteryLifePercent == (byte) 255) ? "Unknown" : BatteryLifePercent + "%";
        }

        /**
         * The number of seconds of battery life remaining
         */
        public String getBatteryLifeTime() {
            return (BatteryLifeTime == -1) ? "Unknown" : BatteryLifeTime + " seconds";
        }

        /**
         * The number of seconds of battery life when at full charge
         */
        public String getBatteryFullLifeTime() {
            return (BatteryFullLifeTime == -1) ? "Unknown" : BatteryFullLifeTime + " seconds";
        }

        @Override
        public String toString() {
            StringBuilder sb = new StringBuilder();
            sb.append("ACLineStatus: " + getACLineStatusString() + "\n");
            sb.append("Battery Flag: " + getBatteryFlagString() + "\n");
            sb.append("Battery Life: " + getBatteryLifePercent() + "\n");
            sb.append("Battery Left: " + getBatteryLifeTime() + "\n");
            sb.append("Battery Full: " + getBatteryFullLifeTime() + "\n");
            return sb.toString();
        }
    }

    /**
     * Fill the structure.
     */
    public int GetSystemPowerStatus(SYSTEM_POWER_STATUS result);
}

以下是如何使用它，例如：在你的main() method:

Kernel32.SYSTEM_POWER_STATUS batteryStatus = new Kernel32.SYSTEM_POWER_STATUS();
Kernel32.INSTANCE.GetSystemPowerStatus(batteryStatus);

System.out.println(batteryStatus); // Shows result of toString() method.

这会在我的 Latitude E5500 上成功打印以下内容：

ACLineStatus: Online
Battery Flag: High, more than 66 percent
Battery Life: 100%
Battery Left: Unknown
Battery Full: Unknown
  

关闭交流电源 10 分钟后：

ACLineStatus: Offline
Battery Flag: High, more than 66 percent
Battery Life: 82%
Battery Left: 2954 seconds
Battery Full: Unknown
  

（不，电池没有坏，我只是在编译电影并现在通过 wifi 不断传输；））