Peter M. Groen / openbr

Commit fc7593c35a68b663a807cd00d3e199888acaa237

Authored by jcheney
1 parent 248a35a4

Basic JNI transform with basic framework for calling Java from OpenBR

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Showing 4 changed files with 123 additions and 0 deletions
openbr/plugins/jni.cmake 0 → 100644
  View file @fc7593c
  1 +set(BR_WITH_JAVA ON CACHE BOOL "Use Java Code")
  2 +
  3 +if (${BR_WITH_JAVA})
  4 + find_package(JNI REQUIRED)
  5 + find_package(JAVA REQUIRED)
  6 + set(BR_THIRDPARTY_SRC ${BR_THIRDPARTY_SRC} plugins/jni.cpp)
  7 + set(BR_THIRDPARTY_LIBS ${BR_THIRDPARTY_LIBS} ${JNI_LIBRARIES})
  8 +
  9 + include_directories(${JAVA_INCLUDE_PATH})
  10 + include_directories(${JAVA_INCLUDE_PATH2})
  11 +
  12 +endif()
... ...
openbr/plugins/jni.cpp 0 → 100644
  View file @fc7593c
  1 +//Need to include location of jvm.dll (jdk version) and its parent directory in the environment variables
  2 +
  3 +#include <limits>
  4 +#include "openbr_internal.h"
  5 +#include "openbr/core/resource.h"
  6 +#include <jni.h>
  7 +
  8 +namespace br
  9 +{
  10 +
  11 +/*!
  12 + * \ingroup initializers
  13 + * \brief Initialize JNI
  14 + * \author Jordan Cheney \cite jcheney
  15 + */
  16 +class JNIInitializer : public Initializer
  17 +{
  18 + Q_OBJECT
  19 + public:
  20 + static JavaVM* jvm;
  21 + static JavaVMInitArgs vm_args;
  22 +
  23 + void initialize() const
  24 + {
  25 + JNIEnv *env;
  26 + JavaVMOption options[1];
  27 +
  28 + //Location of Java files
  29 + QByteArray classpath = QString("-Djava.class.path=").append(Globals->sdkPath).append(QString("/share/openbr/Java/jniLibraries/")).toLocal8Bit();
  30 + char *charClasspath = classpath.data();
  31 +
  32 + options[0].optionString = charClasspath;
  33 + vm_args.version = JNI_VERSION_1_6;
  34 + vm_args.nOptions = 1;
  35 + vm_args.options = options;
  36 + vm_args.ignoreUnrecognized = JNI_FALSE;
  37 +
  38 + JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args);
  39 +
  40 + Globals->abbreviations.insert("JNIHelloWorld","Open+JNI(HelloWorld)");
  41 + }
  42 +
  43 + void finalize() const
  44 + {
  45 + jvm->DestroyJavaVM();
  46 + }
  47 +};
  48 +
  49 +JavaVM *JNIInitializer::jvm;
  50 +JavaVMInitArgs JNIInitializer::vm_args;
  51 +
  52 +BR_REGISTER(Initializer, JNIInitializer)
  53 +
  54 +/*!
  55 + * \ingroup transforms
  56 + * \brief Execute Java code from OpenBR using the JNI
  57 + * \author Jordan Cheney \cite jcheney
  58 + */
  59 +
  60 +class JNITransform : public UntrainableTransform
  61 +{
  62 + Q_OBJECT
  63 + Q_PROPERTY(QString className READ get_className WRITE set_className RESET reset_className STORED false)
  64 + BR_PROPERTY(QString, className, "")
  65 +
  66 + void project(const Template &src, Template &dst) const
  67 + {
  68 + JNIEnv *env;
  69 +
  70 + //Attach current thread to the thread of the JavaVM and access env
  71 + JNIInitializer::jvm->AttachCurrentThreadAsDaemon((void**)&env, NULL);
  72 + if (JNIInitializer::jvm->GetEnv(reinterpret_cast<void**>(&env), JNI_VERSION_1_6) != JNI_OK) {
  73 + qFatal("Failed to initialize JNI environment");
  74 + }
  75 +
  76 + //Convert QString to const char*
  77 + QByteArray tmpClass = className.toLocal8Bit();
  78 + const char* charClassName = tmpClass.constData();
  79 +
  80 + //Call java method
  81 + jclass cls = env->FindClass(charClassName);
  82 + if (cls == NULL) { qFatal("Class not found"); }
  83 + jmethodID mid = env->GetStaticMethodID(cls, "project", "(Ljava/lang/String;)V");
  84 + if (mid == NULL) { qFatal("MethodID not found"); }
  85 +
  86 + QByteArray tmp = src.file.name.toLocal8Bit();
  87 + const char* fileName = tmp.constData();
  88 +
  89 + //Convert char* to java compatible string
  90 + jstring jfileName = env->NewStringUTF(fileName);
  91 +
  92 + env->CallStaticObjectMethod(cls, mid, jfileName);
  93 +
  94 + JNIInitializer::jvm->DetachCurrentThread();
  95 + }
  96 +};
  97 +
  98 +BR_REGISTER(Transform, JNITransform)
  99 +
  100 +} // namespace br
  101 +
  102 +#include "jni.moc"
... ...
share/openbr/Java/jniLibraries/HelloWorld.jar 0 → 100644
View file @fc7593c
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share/openbr/Java/jniLibraries/HelloWorld.java 0 → 100644
  View file @fc7593c
  1 +public class HelloWorld {
  2 + public static void project(String imgPath) {
  3 + System.out.println();
  4 + System.out.println("Welcome to the OpenBR JNI transform! The image path string " + imgPath + " has been passed here from C++.");
  5 + System.out.println("To incorporate your Java code into OpenBR assemble a jar file will of the relevant classes and save it in the openbr/share/openbr/Java/jniLibraries folder.");
  6 + System.out.println("For documentation and additional resources on the JNI visit 'https://docs.oracle.com/javase/1.5.0/docs/guide/jni/specs/functions.html'");
  7 + System.out.println();
  8 + }
  9 +}
0 10 \ No newline at end of file
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