函数JNI_createJavaJVM中的JNI错误
我在实例化JVM时遇到了一些问题。如果我独立运行下面的代码,它可以正常工作。但是,我需要将它集成到一个更大的工具中,称为java库 程序首先调用createVM方法,然后调用invokePrismWrapper方法。但是,方法JNI_CreateJavaVM(…)返回JNI_ERR 预处理器函数JNI_createJavaJVM中的JNI错误,java,c++,jvm,java-native-interface,Java,C++,Jvm,Java Native Interface,我在实例化JVM时遇到了一些问题。如果我独立运行下面的代码,它可以正常工作。但是,我需要将它集成到一个更大的工具中,称为java库 程序首先调用createVM方法,然后调用invokePrismWrapper方法。但是,方法JNI_CreateJavaVM(…)返回JNI_ERR 预处理器 #define USER_CLASSPATH ".:../ .... CreateVM函数 JNIEnv* createVM (JavaVM **jvm) { JNIEnv *env;
#define USER_CLASSPATH ".:../ ....
CreateVM函数
JNIEnv* createVM (JavaVM **jvm)
{
JNIEnv *env; /* pointer to native method interface */
JavaVMInitArgs vm_args; /* JDK/JRE 6 VM initialization arguments */
JavaVMOption* options = new JavaVMOption[1]; //holds various JVM optional settings
options[0].optionString = const_cast<char*>("-Djava.class.path="USER_CLASSPATH);
vm_args.version = JNI_VERSION_1_6; //version of Java platform
vm_args.nOptions = 1;
vm_args.options = options;
vm_args.ignoreUnrecognized = false;
/* load and initialize a Java VM, return a JNI interface * pointer in env */
long status = JNI_CreateJavaVM(jvm, (void**)&env, &vm_args);
if (status == JNI_ERR){
cout << "\n Unable to load JVM \n Exit";
exit(-1);
}
delete options;
return env;
}
非常感谢您的帮助。那么导致此失败的较大程序有什么不同呢?
createVM
函数声明它返回指向JNIEnv
的指针,但没有返回语句。你真的在运行这段代码吗?还是你修改了它?我忘了复制/粘贴return语句。我还使用为编译代码而编写的CMake脚本更新了主题@欧内斯特·弗里德曼·希尔:问题是,当我从大型软件调用createVM函数时,它会停止。当我把它作为一个独立的应用程序使用时,它执行得很好。两个EXE都是32位(或64位)?@doctorlove:64位。我可以作为独立应用程序运行这两个类(较大的软件和创建JVM并调用java类的绑定类)。但是,我无法从大型软件运行绑定类
float invokePrismWrapper(JavaVM **jvm, JNIEnv *env){
jclass mainClass = env->FindClass(MainClass); //Returns a class object from a fully-qualified name, or NULL if the class cannot be found.
jmethodID classConstructor = env->GetMethodID(mainClass, "<init>", "()V"); //Returns the method ID for an instance (nonstatic) method of a class
jobject classObject = env->NewObject(mainClass, classConstructor); //Constructs a new java object
float outcome = 0;
if (mainClass!=0){
jmethodID methodid = env->GetMethodID(mainClass, "goPrism", "()Ljava/lang/String;");
if (methodid!=0){
jstring result = (jstring)env->CallObjectMethod(classObject, methodid); //returns the result of the calling method, an object
const jbyte *str = (jbyte *)(env)->GetStringUTFChars(result, NULL); // Returns a pointer to an array of bytes representing the string in modified UTF-8 encoding
outcome = ::atof((char*)str);
env->ReleaseStringUTFChars(result, (char*)str);
cout << "Result: " << outcome << endl;
}
else{
cout << "Method not found!" << endl;
}
return outcome;
}
else{
cout << "Class Not found" << endl;
return -1;
}
}
cmake_minimum_required(VERSION 2.8.6)
FIND_PACKAGE(JNI REQUIRED)
SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -I/usr/lib/jvm/java-6-openjdk-amd64/include -I/usr/lib/jvm/java-6-openjdk-amd64/include/linux -L/usr/lib/jvm/java-6-openjdk-amd64/jre/lib/amd64/server")
SET(CMAKE_EXE_LINKER_FLAGS "-ljvm")
# add the binary tree directory to the search path for include files
INCLUDE_DIRECTORIES(${CMAKE_CURRENT_SOURCE_DIR})
INCLUDE_DIRECTORIES(${JNI_INCLUDE_DIRS})
ADD_LIBRARY(PRISMLibrary SHARED JNIWrapper.cpp)
message("JNI:- " ${JNI_LIBRARIES})
message("Source Dir: - " ${PROJECT_SOURCE_DIR})
TARGET_LINK_LIBRARIES (PRISMLibrary ${JNI_LIBRARIES})