NoSuchMethodError 使用 JNA User32 平台映射

Question

I received the following error on the first attempt of using the User32.Instance:

Exception in thread "main" java.lang.NoSuchMethodError: com.sun.jna.Native.load(Ljava/lang/String;Ljava/lang/Class;Ljava/util/Map;)Lcom/sun/jna/Library;
at com.sun.jna.platform.win32.User32.(User32.java:48)

whilst trying to run a JNA pre-defined mapping of the Windows User32 class functions.

I tried running the following code:

HWND hwnd = User32.INSTANCE.FindWindow(null,"new 2 - Notepad++");
User32.INSTANCE.SetForegroundWindow(hwnd);

Do I have to declare my own Interface or am I able to use the User32 JNA mapping located in jna-platform? What am i doing wrong?

Edit: The error is on this line from the com.sun.jna.platform.win32.user32:

User32 INSTANCE = Native.load("user32", User32.class, W32APIOptions.DEFAULT_OPTIONS);

Answer 1

I was able to reproduce this bug by compiling against an old jna package (pre-5.0.0) and a new jna-platform package (5.0.0):

Exception in thread "main" java.lang.NoSuchMethodError: com.sun.jna.Native.load(Ljava/lang/String;Ljava/lang/Class;Ljava/util/Map;)Lcom/sun/jna/Library;
    at com.sun.jna.platform.win32.User32.<clinit>(User32.java:48)
    at sandboxjava.Main.main(Main.java:8)

The issue is that JNA deprecated the Native.loadLibrary method in version 5.0.0 and introduced the Native.load method. The newer jna-platform package uses the new method, but because the jna package is an older version, the load method simply does not exist in the package.

You should either upgrade the jna package to 5.0.0 (latest at the time of writing), or downgrade jna-platform to a pre-5.0.0 version.

Answer 2

Update the maven using below dependency, It worked for me.

    <dependency>
        <groupId>net.java.dev.jna</groupId>
        <artifactId>jna</artifactId>
        <version>4.5.1</version>
    </dependency>

Answer 3

In my project, this error occurs when the following three dependency exist simultaneously. I move the tess4j dependency to the last and it works.

<dependency>
           <groupId>net.sourceforge.tess4j</groupId>
           <artifactId>tess4j</artifactId>
           <version>3.4.0</version>
</dependency>
<dependency>
           <groupId>com.sun.jna</groupId>
           <artifactId>jna</artifactId>
           <version>4.4.0</version>
           <scope>system</scope>
           <systemPath>${project.basedir}\src\resources\lib\opencv\jna- 
           4.4.0.jar</systemPath>
</dependency>
<dependency>
            <groupId>com.sun.jna.paltform</groupId>
            <artifactId>paltform</artifactId>
            <version>4.4.0</version>
            <scope>system</scope>
            <systemPath>${project.basedir}\src\resources\lib\opencv\jna-platform-4.4.0.jar</systemPath>
</dependency>