cocos2dx項目在三星tab3設備碼獲取失敗的閃退問題及解決

具體動作：
點擊登陸後，客戶端需提取設備碼提交到服務器，出現崩潰問題；

logcat錯誤信息如下：

12-16 16:58:53.645: E/dalvikvm(19006): JNI ERROR (app bug): accessed stale weak global reference 0xffffffff (index 65535 in a table of size 0)
12-16 16:58:53.645: E/dalvikvm(19006): VM aborting
12-16 16:58:53.645: A/libc(19006): Fatal signal 11 (SIGSEGV) at 0xdeadd00d (code=1), thread 19021 (Thread-1317)

使用萬能的ndk-stack -sym 跟蹤

********** Crash dump: **********
Build fingerprint: 'samsung/lt01wifizc/lt01wifi:4.2.2/JDQ39/T310ZCUAMJ1:user/release-keys'
pid: 19006, tid: 19021, name: Thread-1317  >>> package name <<<
signal 11 (SIGSEGV), code 1 (SEGV_MAPERR), fault addr deadd00d
Stack frame #00  pc 00045cd8  /system/lib/libdvm.so (dvmAbort+75)
Stack frame #01  pc 0002862c  /system/lib/libdvm.so (IndirectRefTable::get(void*) const+336)
Stack frame #02  pc 0004a2a1  /system/lib/libdvm.so (dvmDecodeIndirectRef(Thread*, _jobject*)+132)
Stack frame #03  pc 0004b191  /system/lib/libdvm.so
Stack frame #04  pc 003b5ccc  /data/app-lib/package name-1/libgame.so (_JNIEnv::GetStringUTFChars(_jstring*, unsigned char*)+48): Routine GetStringUTFChars in (null):0
Stack frame #05  pc 005f8110  /data/app-lib/package name/libgame.so: Routine jstring2string_ in /Users/chenxu/work/c++/cocos2d-x-2.1.4/work/appname/proj.android/../../../cocos2dx/platform/android/jni/JniHelper.cpp:174
Crash dump is completed

目標代碼：原因可能是拿不到imei,所以數值爲空;
//查看設備唯一碼

std::string NativeCallJni::getImei()
{
    LoggerUtil::getLogger()->logInfo(__FUNCTION__);

    std::string imeiStr = "";    
#if (CC_TARGET_PLATFORM == CC_PLATFORM_ANDROID)
    {
        JniMethodInfo mInfo;//定義Jni函數信息結構體
        bool isHave = JniHelper::getStaticMethodInfo(mInfo,JNI_CLASS_PATH,"getIMEI","()Ljava/lang/String;");
        if (isHave)
        {
            jstring imei = (jstring)mInfo.env->CallStaticObjectMethod(mInfo.classID,mInfo.methodID);
            imeiStr = JniHelper::jstring2string(imei);
        }
    }
#endif
    return imeiStr;
}

cocos2dx的JniHelper.cpp代碼

    static string jstring2string_(jstring jstr)
    {
        if (jstr == NULL)
        {
            return "";
        }

        JNIEnv *env = 0;

        if (! getEnv(&env))
        {
            return 0;
        }

        #此處報錯android4.0嚴格，如果輸入值爲空，則崩潰
        const char* chars = env->GetStringUTFChars(jstr, NULL);   
        string ret(chars);
        env->ReleaseStringUTFChars(jstr, chars);

        return ret;
    }
}

崩潰的原因應該明白了，就是在提取不到imei的情況下，
jstring imei = (jstring)mInfo.env->CallStaticObjectMethod(mInfo.classID,mInfo.methodID);
iemi = null的話調用
imeiStr = JniHelper::jstring2string(imei);
此處報錯android4.0嚴格，如果輸入值爲空，則崩潰

現在的解決辦法就是獲取一個能夠替代deviceid的其他的特徵碼。我這裏考慮採用cpu serial作爲唯一碼
具體代碼如下

  private static String getIdentifierByCpu() {
    String identifier = "";
    String cmdStr = "cat /proc/cpuinfo";

    Process process;
    try {
      process = Runtime.getRuntime().exec(cmdStr);
      InputStreamReader reader = new InputStreamReader(
          process.getInputStream());
      LineNumberReader lineReader = new LineNumberReader(reader);
      String line = "";
      while ((line = lineReader.readLine()) != null) {
        if (line.startsWith("Serial")) {
          identifier = line.split(":")[1];
          Log.i(TAG, identifier);
        }
      }
    } catch (IOException e) {
      Log.e(TAG, e.getMessage());
    }
    return identifier;
  }

測試驗證通過。今天又瞭解一個通過linux 命令行獲取系統信息的方法，就是 Runtime.getRuntime().exec(cmd)

另外小技巧。tab3的debug模式，需要google下，挺有意思的打開方式，各位自己動手下吧。

下次碰到有意思的問題，繼續分享給大家。