Databases
StackOverflow2013
Postsdbo
POHow to get device id with JNI in Android?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHow to get device id with JNI in Android?
    primarykey
    data
    text
    <p>I want to get IMEI from c by <code>JNI</code>, I use the code below, but met the error that failed to get <code>cls</code>, it always returned <code>NULL</code>.I checked env and context, they were all right.Why couldn't me get the <code>Context</code> class? I searched from the internet, someone says we should use <code>java/lang/Object</code> instead of using <code>android/context/Context</code>, I tried this, it works, cls wasn't NULL any longer,but it caused new error when I call <code>getSystemService</code>, maybe because common <code>java/lang/Object</code> dosn't have this method.Could anyone help me?3Q. </p> <pre><code>char * get_dev_id(JNIEnv *env, jobject context) { jclass cls = (*env)-&gt;FindClass(env, "android/context/Context"); // ---------------- cls == NULL all the time jmethodID mid = (*env)-&gt;GetMethodID(env, cls, "getSystemService", "(Ljava/lang/String;)Ljava/lang/Object;"); jfieldID fid = (*env)-&gt;GetStaticFieldID(env, cls, "TELEPHONY_SERVICE", "Ljava/lang/String;"); jstring str = (*env)-&gt;GetStaticObjectField(env, cls, fid); jobject telephony = (*env)-&gt;CallObjectMethod(env, context, mid, str); cls = (*env)-&gt;FindClass(env, "android/telephony/TelephonyManager"); mid =(*env)-&gt;GetMethodID(env, cls, "getDeviceId", "()Ljava/lang/String;"); str = (*env)-&gt;CallObjectMethod(env, telephony, mid); jsize len = (*env)-&gt;GetStringUTFLength(env, str); char* deviceId = calloc(len + 1, 1); (*env)-&gt;GetStringUTFRegion(env, str, 0, len, deviceId); (*env)-&gt;DeleteLocalRef(env, str); /* to get a string in deviceId */ return deviceId; } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USSuge
    1. USSuge
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. COYes, I've loaded the jni.so, and the context I passed into the function is the `this.getApplicationContext()` result of `MainActivity`, am I somewhere wrong?
      singulars
      1. POHow to get device id with JNI in Android?
      1. USSuge
    2. COI got it, it should be "android/content/Context", not "android/context/Context", looks many one got wrong.
      singulars
      1. POHow to get device id with JNI in Android?
      1. USSuge
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload