NumberFormatException in Try-Catch while converting String to Int

Question

I am trying to convert String to Int in try-catch block. In my case, if the button is clicked,number inside the textview will be converted from String to Int. It is working when I use OnclickListener, I don't even need to use try-catch. But for OnkeyListener, I get "numberformatexception:invalid int" error. I even tried to use try-catch. But it still shows me this error. I really don't get why it works for OnClickListener but not for OnKeyListener. Here is my code-

    var ID = findViewById<EditText>(R.id.edt_id)
    btn_add.setOnClickListener {
        val item=Item(
            Integer.parseInt(edt_id.text.toString()),
            Integer.parseInt(quan.toString()),
            edt_name.text.toString(),
            name.toString(),
            date_record.toString(),
            location_record.toString(),
            master_record.toString().toInt()
        )
        db.addItem(item)
        refreshData()

    edt_id.setOnKeyListener(View.OnKeyListener { v, keyCode, event ->

        if (keyCode == KeyEvent.KEYCODE_ENTER && event.action == 
    KeyEvent.ACTION_UP) {
            //Perform Code
            val ii:String = ID.text.toString()
            var id:Int = 0

            try {
                id = Integer.parseInt(ii)
                println(id!!)
                 Integer.parseInt(quan.toString())
                 Integer.parseInt(record_code.toString())
                println("GG")


            edt_id.text.toString()
                val item=Item(
                    id,
                    Integer.parseInt(quan.toString()),
                    edt_name.text.toString(),
                    name.toString(),
                    date_record.toString(),
                    location_record.toString(),
                    Integer.parseInt(record_code.toString())
                )
                db.addItem(item)
                refreshData()
                edt_id.text=null
                edt_id.requestFocus()                
                true}
        catch (nfe:NumberFormatException )
        { nfe.printStackTrace() }
            }
        false

    })

Answer 1

if you are using Kotlin, the safest way is using toIntOrNull() for example:

"10".toIntOrNull()

if the string is non number, it will return null instead. after this you could use elvis operator to check if the number is null, then return another value:

val number = "ten".toIntOrNull() ?: 0 

// "ten" is non number, will return null instead, 
// then catch the null with elvis operator ?: and fall back to default value 0

you also could make your code become more simpler, like:

    val item=Item(
        ID.text.toIntOrNull() ?: 0,
        quan.toString().toIntOrNull() ?: 0),
        edt_name.text.toString(),
        name.toString(),
        date_record.toString(),
        location_record.toString(),
        record_code.toString().toIntOrNull() ?: 0
    )
    db.addItem(item)
    refreshData()
    edt_id.text=null
    edt_id.requestFocus()                
    true