1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
| #ifdef __BORLANDC__
#pragma argsused
#endif
#ifdef _WIN32
#define PATH_SEPARATOR ';'
#else
#define PATH_SEPARATOR ':'
#endif
#include <jni.h>
#include <windows.h>
/**
* You can find all installed JVMs' information in the Registry:
* HKEY_LOCAL_MACHINE\SOFTWARE\JavaSoft\Java Runtime Environment
*/
// typedef of functions needed to create the JVM dynamically
typedef jint (JNICALL GetCreatedJavaVMs_t)( JavaVM**, jsize, jsize* );
typedef jint (JNICALL CreateJavaVM_t)( JavaVM**, void **, void* );
// pointer declaration of those functions
GetCreatedJavaVMs_t *GetCreatedJavaVMs;
CreateJavaVM_t *CreateJavaVM;
// handling reference to jvm.dll
HINSTANCE hJvmDll;
int main( int argc, char * argv[] )
{
jsize nVMs;
// pointer to the Virtual Machine instance interface
JavaVM *jvm = (JavaVM *)0;
// pointer to the thread instances interface which invokes Native APIs
JNIEnv *env = (JNIEnv *)0;
JavaVMInitArgs vm_args;
jint status = -1;
jclass cls;
jmethodID mid;
jint square, argsres;
jboolean bNot;
JavaVMOption options[1];
options[0].optionString = "-Djava.class.path=.";
// options[1].optionString = "-verbose";
size_t bufLen = 1;
jvm = (JavaVM *) malloc( sizeof(JavaVM) * bufLen );
char debugStr[256];
hJvmDll =
LoadLibrary( "C:\\Program Files\\Java\\jre1.5.0_04\\bin\\client\\jvm.dll" );
if ( hJvmDll != NULL )
{
GetCreatedJavaVMs =
(GetCreatedJavaVMs_t*)GetProcAddress( hJvmDll, "JNI_GetCreatedJavaVMs" );
CreateJavaVM =
(CreateJavaVM_t*)GetProcAddress( hJvmDll, "JNI_CreateJavaVM" );
if ( GetCreatedJavaVMs != NULL && CreateJavaVM != NULL)
{
status = GetCreatedJavaVMs( &jvm, bufLen, &nVMs);
if ( status == JNI_OK )
{
sprintf( debugStr, "There are %d VM(s) running\r\n", nVMs );
printf(debugStr);
}
if (nVMs == 0)
{
vm_args.version = JNI_VERSION_1_4;
vm_args.options = options;
vm_args.nOptions = 1;
vm_args.ignoreUnrecognized = JNI_TRUE;
status = CreateJavaVM( &jvm, (void**) &env, &vm_args );
if ( status == JNI_OK )
{
sprintf( debugStr, "Launching VM okay.\r\n" );
printf(debugStr);
}
}
}
}
if (status == JNI_OK)
{
cls = (env)->FindClass("Sample2");
if(cls !=0)
{ mid = (env)->GetStaticMethodID( cls, "intMethod", "(I)I");
if(mid !=0)
{ square = (env)->CallStaticIntMethod(cls, mid, 5);
printf("Result of intMethod: %d\n", square);
}
mid = (env)->GetStaticMethodID(cls, "booleanMethod", "(Z)Z");
if(mid !=0)
{ bNot = (env)->CallStaticBooleanMethod(cls, mid, 1);
printf("Result of booleanMethod: %d\n", bNot);
}
}
(jvm)->DestroyJavaVM();
return 0;
}
else
return status;
} |
