android databinding error:Execution failed for task ':app:dataBindingProcessLayoutsDebug'

Question

my partner in ours' project use android databinding.in my pc had error,but in his mac not error.i cant resolve this program.please help:! it's my build.gradle:

dataBinding {
    enabled = true
}

the first build androidstudio say

com.sun.org.apache.xerces.internal.impl.io.MalformedByteSequenceException:       Invalid byte 2 of 2-byte UTF-8 sequence.

then i resave XML file use UTF-8.but a new problem birth.like this:

:app:dataBindingProcessLayoutsDebug
line 1:0 mismatched input '?' expecting {COMMENT, SEA_WS, '<', PI}
Error:Execution failed for task ':app:dataBindingProcessLayoutsDebug'.

java.lang.NullPointerException (no error message)

    <?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:bind="http://schemas.android.com/apk/res-auto">
    <data>
        <import type="android.view.View"/>
        <import type="com.vomoho.vomoho.common.Utils"/>
        <variable name="postDetail" type="com.vomoho.vomoho.entity.PostDetail" />
    </data>
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@color/white"
        android:orientation="vertical">

        <include
            android:id="@+id/top"
            layout="@layout/dt_item_postdetail_top"
            bind:postDetail="@{postDetail}"/>

        <ImageView
            android:id="@+id/img1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginLeft="15dp"
            android:layout_marginTop="8dp"
            android:scaleType="centerCrop"
            android:visibility="@{Utils.getPostType(postDetail.picList) == 0 ? View.GONE : View.VISIBLE}"
            bind:imageUrl="@{postDetail.picList.size() > 0 ? postDetail.picList.get(0) : ``}"
            bind:width="@{Utils.getPostImgWidth(Utils.getPostType(postDetail.picList))}"
            bind:height="@{Utils.getPostImgHeight(Utils.getPostType(postDetail.picList))}" />

        <include
            android:id="@+id/bottom"
            layout="@layout/dt_item_postdetail_bottom"
            bind:postDetail="@{postDetail}"/>
    </LinearLayout>
    </layout>  

Answer 1

I have the same problem, and I finally found the solution.
I found that there is a layout xml file was written like that:

<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text='@{"年龄 " + String.valueOf(user.age)}'/>

and then it cannot built on Windows platform, but it can built on Mac OS X platform, I think its a bug of Android Data Binding, so my temporary solution is:
don't writing any character in @{} section, use string reference instead. (in my case, its replace as android:text='@{ @string/age_text + String.valueOf(user.age) }'/> )
hope it helps you.

Answer 2

I also had this error. In my case I there was a redundant xml header at the bottom of a layout file.

Try removing the whitespace (or removing the header), changing:

    <?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"

to...

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"

Answer 3

I had the same kind of problem with this log:

line 1:0 extraneous input '' expecting {COMMENT, SEA_WS, '<', PI}

This was super strange to me, no real feedback. To solve it:

1. Created new layout resource files
2. Copy and paste the content of the original ones leaving out just the first character
3. Adding it myself in the new file.

Answer 4

Suffered the same problem for one day, finally found out the root cause. Andoid gradle plugin does not handle the encoding with Byte order mark (BOM) well. It is a encoding reading problem. If the file is saved in UTF-8 BOM format, Android gradle tool will detect the encoding as “UTF-8” with UniversalDetector library. The class android.databinding.tool.store.LayoutFileParser will read like this:

InputStreamReader reader = new InputStreamReader(fin, “UTF-8”);

The first character returned by reader.read() is 0xfeff . Yes it is the '?' in error message line 1:0 mismatched input '?' expecting {COMMENT, SEA_WS, '<', PI} line 1:0 mismatched input '?' expecting {COMMENT, SEA_WS, '<', PI} .

Refer the magic number of BOM at https://en.wikipedia.org/wiki/Byte_order_mark

How UniversalDetector works at http://chardet.readthedocs.io/en/latest/how-it-works.html

Answer 5

Same situation! My colleagues have no troubles with project on Linux and Mac, but I couldn't built it on Windows.

Finally after 3 days trying to localise exception, I've found 2 layouts causes an error.

In my case trouble was with big cyrillic symbol "И" in android:text attribute databinding layout.

Answer 6

I was getting this error:

line 1:0 mismatched input '?' expecting {COMMENT, SEA_WS, '<', PI}

And, I solved it by removing

<?xml version="1.0" encoding="utf-8"?>

this line from the top of my xml file.

Please note that I'm using viewBinding not dataBinding

 buildFeatures{
    viewBinding true
}