UnsatisfiedLinkError with JACOB and jre 1.7

问题

I put together a program that uses JACOB to access iTunes ... It works fine in Eclipse but when I export it and run it in the command prompt I get an unsatisfied link error telling me that jacob-1.17-M2-x86.dll is not in my java.library.path.

Ive tried putting it in system32, setting the native library location to its directory...ive tried using the system.setproperties trick...and i couldnt figure out how to use java -d properly

What else can I do? ive been searching the web trying to get this compatible for over 4 hours and nothing seems to work.

回答1:

I found an amazing post by a sun programmer that fixed my problem!

public static void addDir(String s) throws IOException {
    try {
        // This enables the java.library.path to be modified at runtime
        // From a Sun engineer at http://forums.sun.com/thread.jspa?threadID=707176
        Field field = ClassLoader.class.getDeclaredField("usr_paths");
        field.setAccessible(true);
        String[] paths = (String[])field.get(null);
        for (int i = 0; i < paths.length; i++) {
            if (s.equals(paths[i])) {
                return;
            }
        }
        String[] tmp = new String[paths.length+1];
        System.arraycopy(paths,0,tmp,0,paths.length);
        tmp[paths.length] = s;
        field.set(null,tmp);
        System.setProperty("java.library.path", System.getProperty("java.library.path") + File.pathSeparator + s);
    } catch (IllegalAccessException e) {
        throw new IOException("Failed to get permissions to set library path");
    } catch (NoSuchFieldException e) {
        throw new IOException("Failed to get field handle to set library path");
    }
}

Then I added before my use of the JACOB methods

addDir("C:" + File.separator + "java" + File.separator + "jre7" + File.separator + "lib")

Worked like a charm.

回答2:

Another workaround:

Just before you try to load the file, go to ClassLoader.java (java\lang\ClassLoader.java). Set a breakpoint at the following line:

File libfile = new File(sys_paths[i], System.mapLibraryName(name));

That function is located in function:

static void loadLibrary(Class<?> fromClass, String name, boolean isAbsolute)

When you did the breakpoint and you use IntelliJ, you will notice in grey a path where it is looking for. My path was C:\Program Files\Java\jdk1.8.0_161\jre\bin. When you put the needed DLL's filed there, it will work.

来源：https://stackoverflow.com/questions/15941234/unsatisfiedlinkerror-with-jacob-and-jre-1-7

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unsatisfiedlinkerror

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