calling tesseract functions from java

Question

I just downloaded libtesseract302 and like to use some of its exported functions from a java application through JNA. The library is successfully loaded by my test applications but the functions are not found. My simple tesseract api interface looks like this: {{{ public interface TessAPI extends Library {

    public static final TessAPI INSTANCE = (TessAPI) Native.loadLibrary("libtesseract302", TessAPI.class);

    int Init(String datapath, String language);

    public static class TessBaseAPI extends PointerType {

        public TessBaseAPI(Pointer address) {
            super(address);
        }

        public TessBaseAPI() {
            super();
        }
    };
}

}}}

When I try to use this code I get this exception:

    java.lang.UnsatisfiedLinkError: Error looking up function 'Init': A megadott eljárás nem található.

at com.sun.jna.Function.<init>(Function.java:179)
at com.sun.jna.NativeLibrary.getFunction(NativeLibrary.java:350)
at com.sun.jna.NativeLibrary.getFunction(NativeLibrary.java:330)
at com.sun.jna.Library$Handler.invoke(Library.java:203)
at $Proxy5.Init(Unknown Source)
at net.docca.backend.ocr.TesseractApplication.run(TesseractApplication.java:53)
at net.docca.backend.ocr.TesseractApplicationTest.testRun(TesseractApplicationTest.java:103)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:80)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:714)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:901)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1231)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:128)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:111)
at org.testng.TestRunner.privateRun(TestRunner.java:767)
at org.testng.TestRunner.run(TestRunner.java:617)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:334)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:329)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:291)
at org.testng.SuiteRunner.run(SuiteRunner.java:240)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1203)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1128)
at org.testng.TestNG.run(TestNG.java:1036)
at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:111)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:204)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:175)

I think this is because the exported functions in the dll has strange names, for example: ?Init@TessBaseAPI@tesseract@@QEAAHPEBD0@Z

My question is: how should I call my methods in the above code so that they're mapped to the correct dll functions?

Answer 1

看一下Tess4J ，它也使用JNA调用Tesseract API。