SetStatic<type>Field Routines - SetStaticObjectField
void SetStatic<type>Field(JNIEnv *env, jclass clazz, jfieldID fieldID, NativeType value);
This family of accessor routines sets the value of a static field of an object. The field to access is specified by a field ID, which is obtained by calling
GetStaticFieldID(). (SetStaticObjectField)
The following table describes the set routine name and value types. You should replace type in SetStatic<type>Field with the Java type of the field, or one of the actual set static field routine names from the table, and replace NativeType with the corresponding native type for that routine.
Table 4-6a SetStatic<type>Field Family of Accessor Routines
LINKAGE:
Indices in the JNIEnv interface function table.
Table 4-6b SetStatic<type>Field Family of Accessor Routines
PARAMETERS:
env: the JNI interface pointer.clazz: a Java class object.fieldID: a static field ID.value: the new value of the field.
Example of SetStaticObjectField
JNIEXPORT void JNICALL Java_JniExample_org_1native_1call (JNIEnv *env, jclass clazz, jobject obj) {
// Lookup the integer field ('intField') in 'obj' and get its value
jfieldID intFieldId = env->GetFieldID(clazz, "intField", "I");
if (id == 0) throw JNIException("Field not found");
int intFieldVal = env->GetIntField(obj, intFieldId);
// Lookup the static String field ('stringField') in 'obj', then convert the Java string representation
// to C++ type 'const char *'.
jfieldID strFieldId = env->GetStaticFieldID(clazz, "stringField", "Ljava/lang/String;");
if (id == 0) throw JNIException("Field not found");
jstring jstr = (jstring) env->GetStaticObjectField(clazz, strFieldId);
const char *str = (jstr == 0) ? 0 : env->GetStringUTFChars(jstr, 0);
// Lookup the integer array field ('intArray') in 'obj', then convert it to C++ type 'jint *'.
jfieldID arrFieldId = env->GetFieldID(clazz, "intArray", "[I");
if (id == 0) throw JNIException("Field not found");
jintArray jarr = (jintArray) env->GetObjectField(obj, arrFieldId);
jint *arr = env->GetIntArrayElements(jarr, 0);
// Set new values
env->SetIntField(obj, intFieldId, 0);
arr[0] = 0; arr[1] = 0;
env->SetStaticObjectField(clazz, strFieldId, env->NewStringUTF("Good-bye, world!"));
// Explicitly release resources
env->ReleaseIntArrayElements(jarr, arr, 0);
env->ReleaseStringUTFChars(jstr, str);
}
