如何创建HashMap< String,String>通过JNI然后解析为Java [英] How to create HashMap<String, String> through JNI then parse to java
问题描述
我想通过Ndk保护我的Web网址和应用程序秘密密钥,我想在应用程序中创建hashmap
,并且还静态存储密钥值,然后解析为Java,我遵循 Stackoverflow 的回答,例如创建HashMap 也 JNI将对象从C ++传递到Java 某种从上面的链接中弃用的方法,但找不到任何方法,我创建了HashMap
,但它给了我错误
Hi I want to secure my web url and app secret keys through Ndk, I want to create hashmap
in app and also store key values statically then parse to java, I follow Stackoverflow answer like Create HashMap also JNI passing objects from C++ to Java some method deprecated from above link and didn't find any way to do this, I created HashMap
but it giving me error
#include <jni.h>
extern "C"
JNIEXPORT jobject
Java_com_company_project_home_ui_MainActivity_getUrlMap(
JNIEnv *env,
jobject /* this */) {
jclass mapClass = env->FindClass("java/util/HashMap");
if(mapClass == NULL)
{
return NULL;
}
jsize map_len = 1;
jmethodID init = env->GetMethodID(mapClass, "<init>", "(I)V");
jobject hashMap = env->NewObject(mapClass, init, map_len);
jmethodID put = env->GetMethodID(mapClass, "put", "(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;");
char *key = (char*)"URL_TEST_API" ;
char *val = (char*)"home.php";
env->CallObjectMethod(hashMap, put, key, val);
return hashMap;
}
错误
A/art: art/runtime/java_vm_ext.cc:410] native: #12 pc 00dd8f2f /data/app/com.company.project-1/oat/arm/base.odex (void com.company.project.home.ui.MainActivity.onCreate(android.os.Bundle)+714)
推荐答案
我解决了我的问题我在代码中发现的主要问题是我错过了在 JNIEXPORT 之后添加 JNICALL >行,并且因为Key和val无效,所以我通过C更改为Java String(如@Michael在上面的答案中提到的那样),现在经过一些修改后代码正常工作,也更改了()
I solved My Problem the main Problem I found in my code is I missed to add JNICALL after JNIEXPORT line, and as Key and val are not valid so I changed to Java String through C as mentioned by @Michael in above answer, now code working fine after some modification also change ()
#include <jni.h>
extern "C"
JNIEXPORT jobject
JNICALL
Java_com_company_project_somePackage_SplashScreen_getHashMap(JNIEnv *env, jobject /* this */) {
jclass mapClass = env->FindClass("java/util/HashMap");
if(mapClass == NULL)
{
return NULL;
}
jsize map_len = 1;
jmethodID init = env->GetMethodID(mapClass, "<init>", "(I)V");
jobject hashMap = env->NewObject(mapClass, init, map_len);
jmethodID put = env->GetMethodID(mapClass, "put", "(Ljava/lang/Object;Ljava/lang/Object;)Ljava/lang/Object;");
jenv->CallObjectMethod(hashMap, put, env->NewStringUTF("URL_TEST_API"), env->NewStringUTF("home.php"));
return hashMap;
}
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