我最近偶然发现了一个运行时错误，它使我的应用程序因某种原因而崩溃，但我无法找到它的根源。基本上，我正在更新用户配置文件数据，将其存储在一个哈希姆中。这就是用户类的模样。
@Parcelize
data class User(
val id: String = "",
val firstName: String = "",
val lastName: String = "",
val email: String = "",
val image: String = "",
val mobile: Long = 0,
val gender: String = "",
val profileCompleted: Int = 0): Parcelable
在一个名为UserProfileActivity的活动中，我把手机和性别存储到一个哈希玛中，然后调用Firebase函数来更新Firestore数据库。这里是该活动的一个方法。当 "提交 "按钮被点击时，这段代码就会运行。
btn_submit.setOnClickListener {
if(validateUserProfileDetails()){ //checks if entered credentials are valid
val userHashMap = HashMap<String, Any>() //creates the hashmap
val mobileNumber = et_mobile_number.text.toString().trim { it <= ' ' }
val gender = if (rb_male.isChecked) { //these are radio buttons, only 1 clicked
Constants.MALE
} else {
Constants.FEMALE
userHashMap[Constants.MOBILE] = mobileNumber.toLong() //storing info in hashmap
userHashMap[Constants.GENDER] = gender
showProgressDialog(resources.getString(R.string.please_wait)) //starting a progress dialog
FirestoreClass().updateUserProfileData( //method in FirestoreClass
this, userHashMap
现在是与数据库通信的被调用方法。
fun updateUserProfileData(activity: Activity, userHashMap: HashMap<String, Any>) {
mFireStore.collection(Constants.USERS) // collection named "users"
.document(getCurrentUserID()) //getCurrentUserID() just gets the current user id
.update(userHashMap) // hashmap used to update the user
.addOnSuccessListener {
when (activity) {
is UserProfileActivity -> {
activity.userProfileUpdateSuccess() //this just hides the progress dialog and finishes the activity in the UserProfileActivity
.addOnFailureListener { e ->
when (activity) {
is UserProfileActivity -> {
activity.hideProgressDialog()
但我得到了这个错误。
2021-12-27 02:35:38.727 14960-14960/com.example.myshopapp E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.myshopapp, PID: 14960
java.lang.NullPointerException: Parameter specified as non-null is null: method kotlin.jvm.internal.Intrinsics.checkNotNullParameter, parameter it
at com.example.myshopapp.firestore.FirestoreClass.updateUserProfileData$lambda-2(Unknown Source:7)
at com.example.myshopapp.firestore.FirestoreClass.$r8$lambda$vs4EuaGwStcL-i3lXRUecduDHWM(Unknown Source:0)
at com.example.myshopapp.firestore.FirestoreClass$$ExternalSyntheticLambda4.onSuccess(Unknown Source:4)
at com.google.android.gms.tasks.zzm.run(com.google.android.gms:play-services-tasks@@18.0.0:1)
at android.os.Handler.handleCallback(Handler.java:938)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:223)
at android.app.ActivityThread.main(ActivityThread.java:7656)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
我完全不知道空指针异常是在哪里发生的......。有趣的是（这很重要），数据库确实得到了正常的更新，为什么会崩溃呢？如果有任何帮助，我将不胜感激。）
