jni jnienv SetStaticCharField example c c++ java

SetStatic<type>Field Routines - SetStaticCharField

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 callingGetStaticFieldID(). (SetStaticCharField)

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

SetStatic<type>Field Routine Name	NativeType
SetStaticObjectField()	jobject
SetStaticBooleanField()	jboolean
SetStaticByteField()	jbyte
SetStaticCharField()	jchar
SetStaticShortField()	jshort
SetStaticIntField()	jint
SetStaticLongField()	jlong
SetStaticFloatField()	jfloat
SetStaticDoubleField()	jdouble

LINKAGE:

Indices in the JNIEnv interface function table.

Table 4-6b SetStatic<type>Field Family of Accessor Routines

SetStatic<type>Field Routine Name	Index
SetStaticObjectField()	154
SetStaticBooleanField()	155
SetStaticByteField()	156
SetStaticCharField()	157
SetStaticShortField()	158
SetStaticIntField()	159
SetStaticLongField()	160
SetStaticFloatField()	161
SetStaticDoubleField()	162

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 SetStaticCharField

{

jfieldID jFieldId;
jchar iStaticCharVal;
jclass cls = (*env)->GetObjectClass(env, jobj);

jFieldId = (*env)->GetStaticFieldID(env,cls,"iStaticCharVal","C");
if(jFieldId == 0) {
                printf("Field iStaticCharVal not Found in Hello class\n");
                return;
}iStaticCharVal = (*env)->GetStaticCharField(env,cls,jFieldId);
(*env)->SetStaticCharField(env,cls,jFieldId,(iStaticCharVal +2));  

}