JNI和Qt通信 (Part 2)

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JNIEXPORT void JNICALL Java_JNISample_sampleFunction(JNIEnv* env, jobject obj, jstring name) 

{ 

    const char* pname = env->GetStringUTFChars(name, NULL); 

    env->ReleaseStringUTFChars(name, pname); 

}

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JNIEXPORT jint JNICALL Java_IntArray_sumArray  

        (JNIEnv *env, jobject obj, jintArray arr) {  

    jint buf[10];  

    jint i, sum = 0;  

    // This line is necessary, since Java arrays are not guaranteed  

    // to have a continuous memory layout like C arrays.  

    env->GetIntArrayRegion(arr, 0, 10, buf);  

    for (i = 0; i

        sum += buf[i];  

    }  

    return sum;  

}

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// In "win\jni_mh.h" - machine header which is machine dependent

typedef long            jint;

typedef __int64         jlong;

typedef signed char     jbyte;

// In "jni.h"

typedef unsigned char   jboolean;

typedef unsigned short  jchar;

typedef short           jshort;

typedef float           jfloat;

typedef double          jdouble;

typedef jint            jsize;

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class JNISample

{

    public native void launchSample();

    static

    {

        System.loadLibrary("Sample");

    }

    public static int add(int a,int b) {

        return a+b;

    }

    public boolean judge(boolean bool) {

        return !bool;

    }

}

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JNIEnv *env = GetJNIEnv(); //Get env from JNI

jclass cls;

cls = env->FindClass("JNISample");

if(cls !=0)

{

    printf("find java class success\n");

    // constructor

    mid = env->GetMethodID(cls,"<init>"</init>,"()V");

    if(mid !=0)

    {

        jobj=env->NewObject(cls,mid);

    }

    // static function

    mid = env->GetStaticMethodID( cls, "add", "(II)I");

    if(mid !=0)

    {

        square = env->CallStaticIntMethod( cls, mid, 5,5);

    }

    // function returns boolean

    mid = env->GetMethodID( cls, "judge","(Z)Z");

    if(mid !=0){

        jnot = env->CallBooleanMethod(jobj, mid, 1);

    }

}

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javap -s -p -classpath R:\test.Demo

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#ifdef JNI_VERSION_1_4    

printf("Version is 1.4 \n");  

#endif

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jint GetVersion(JNIEnv *env);