java - 在 NDK 中获取 Android ID 时出错

Question

我在NDK中写了一个获取android ID的方法

void getAndroidID(JNIEnv *env, jobject context, char *deviceId){

    int android_id_len = 16;

    //Get the Setting.Secure class and the Context Class
    jclass c_settings_secure = (*env)->FindClass(env, "android/provider/Settings$Secure");
    jclass c_context = (*env)->FindClass(env,"android/content/Context");
    if(c_settings_secure == NULL || c_context == NULL){
        return;
    }
    //Get the getContentResolver method
    jmethodID m_get_content_resolver = (*env)->GetMethodID(env, c_context, "getContentResolver",
                                                           "()Landroid/content/ContentResolver;");
    if(m_get_content_resolver == NULL){
        return;
    }

    //Get the Settings.Secure.ANDROID_ID constant
    jfieldID f_android_id = (*env)->GetStaticFieldID(env, c_settings_secure, "ANDROID_ID", "Ljava/lang/String;");
    if(f_android_id == NULL){
        return;
    }
    jstring s_android_id = (*env)->GetStaticObjectField(env, c_settings_secure, f_android_id);

    //create a ContentResolver instance context.getContentResolver()
    jobject o_content_resolver = (*env)->CallObjectMethod(env, context, m_get_content_resolver);
    if(o_content_resolver == NULL || s_android_id == NULL){
        return;
    }

    //get the method getString
    jmethodID m_get_string = (*env)->GetStaticMethodID(env, c_settings_secure, "getString",
                                                       "(Landroid/content/ContentResolver;Ljava/lang/String;)Ljava/lang/String;");
    if(m_get_string == NULL){
        return;
    }

    //get the Android ID
    jstring android_id = (*env)->CallStaticObjectMethod(env, c_settings_secure,
                                                        m_get_string,
                                                        o_content_resolver,
                                                        s_android_id);
    (*env)->GetStringUTFRegion(env, android_id, 0, android_id_len, deviceId);
    deviceId[android_id_len] = '\0';
    LOGI("deviceId %s", deviceId);
}

我在几部手机上测试了这段代码，它在所有手机上都有效，但在一部手机上我得到了一个异常(exception)StringIndexOutOfBoundsException java.lang.StringIndexOutOfBoundsException: length=15;区域开始=0； regionLength=16当我调用 GetStringUTFRegion 方法时。

为什么我会收到异常，我该如何解决？

Answer 1

您似乎要求翻译的字符多于字符串中的字符 - android_id_len 的硬编码值为 16，而本例中的字符串为 15，作为错误消息说。确保计算字符串的正确长度并将该长度传递给 GetStringUTFRegion，这样您的代码将是跨设备通用的。