返回值的获取

Author: durongze

callc/CallC.java

@@ -1,7 +1,7 @@
 package com.durongze.jni;
 
 public class CallC{
-    public native void CInterface(String[] name, int[] age, float[] height, int num);
+    public native String[] CInterface(String[] name, int[] age, float[] height, int num);
     static {
         System.loadLibrary("CLibrary");
     }
@@ -11,11 +11,14 @@ public static void main(String[] args){
         String[] name = new String[num]; // ("durongze", "duyongze");
         int[] age = new int[num]; // (28, 30);
         float[] height = new float[num]; // (177, 188);
-        for (; idx < num; ++idx){
-            name[idx] = Integer.toString(idx);
-            age[idx] = idx;
-            height[idx] = idx + num;
+        for (idx = 0; idx < num; ++idx){
+            name[idx] = Integer.toString(100 + idx);
+            age[idx] = 200 + idx;
+            height[idx] = 300 + idx;
+        }
+        String[] vals = new CallC().CInterface(name, age, height, num);
+        for (idx = 0; idx < vals.length; ++idx){
+            System.out.println(vals[idx]);
         }
-        new CallC().CInterface(name, age, height, num);
     }
 };

callc/com_durongze_jni_CallC.cpp

@@ -12,23 +12,30 @@ extern "C" {
 /*
  * Class:     com_durongze_jni_CallC
  * Method:    CInterface
- * Signature: ([Ljava/lang/String;[I[FI)V
+ * Signature: ([Ljava/lang/String;[I[FI)[Ljava/lang/String;
  */
-JNIEXPORT void JNICALL Java_com_durongze_jni_CallC_CInterface
+JNIEXPORT jobjectArray JNICALL Java_com_durongze_jni_CallC_CInterface
   (JNIEnv *env, jobject, jobjectArray names, jintArray ages, jfloatArray heights, jint num)
   {
+      jobjectArray result;
+      jclass intArrCls = env->FindClass("java/lang/String");
+      result = env->NewObjectArray(num, intArrCls, NULL);
       int idx = 0;
       jint *as = env->GetIntArrayElements(ages, 0);
+      int asLen = env->GetArrayLength(ages);
       jfloat *hs = env->GetFloatArrayElements(heights, 0);
-      for (; idx < num; ++idx) {
+      int hsLen = env->GetArrayLength(heights);
+      for (idx = 0; idx < num; ++idx) {
         jstring ns = static_cast<jstring>(env->GetObjectArrayElement(names, idx));
         const char* pns = env->GetStringUTFChars(ns,0);
         printf("%s:       names[%d]:%s,         ages[%d]:%d,    heights[%d]:%lf\n",
             __FUNCTION__, idx, pns, idx, as[idx], idx, hs[idx]);
         env->ReleaseStringUTFChars(ns, 0);
+        env->SetObjectArrayElement(result, idx, ns);
       }
       env->ReleaseIntArrayElements(ages, as, 0);
       env->ReleaseFloatArrayElements(heights, hs, 0);
+      return result;
   }
 
 #ifdef __cplusplus