GWT Deferred Binding Error – UiBinder Not Resolved from Dependent Module (phoenix-air)

[Arpan Ameta]

Hi Team,

I’m facing an issue with GWT deferred binding while working with a modular Maven setup and would appreciate any guidance.

Error:

Failed to resolve AwbCustomerUiBinder via deferred binding

---

 Project Setup

We have a multi-module Maven project:

• phoenix-air → packaged as a JAR (contains GWT UI, UiBinder files)

• phoenix-main → WAR (main application)

• Parent project builds all modules

In application.gwt.xml, we are inheriting the air module:

<inherits name="com.shipco.phoenix.air.Air"/>

The dependency is also added in phoenix-main:

<dependency> <groupId>phoenix</groupId> <artifactId>phoenix-air</artifactId> <version>1.0</version> </dependency>

---

 Air Module Details

In phoenix-air:

• AwbCustomer.java uses UiBinder:

interface AwbCustomerUiBinder extends UiBinder<Widget, AwbCustomer> {} private static AwbCustomerUiBinder uiBinder = GWT.create(AwbCustomerUiBinder.class);

• Corresponding file exists:

AwbCustomer.ui.xml

• Both are in the same package:

modules/awb/client/airimport/view/awbpopup/

• air.gwt.xml includes:

<source path="modules/awb/client"/>

• POM includes .ui.xml and .gwt.xml in resources

 Additional Context

• Other modules with similar setup seem to work (possibly not using UiBinder or structured differently)

• Using GWT 2.12.x

• Maven build with net.ltgt.gwt.maven:gwt-maven-plugin

---

Any insights or best practices for structuring GWT modules across Maven projects would be really helpful.

Thanks in advance!

Best regards,
Arpan Ameta

[Thomas Broyer]

On Friday, March 20, 2026 at 1:19:56 PM UTC+1 arpanam...@gmail.com wrote:

> 
>   * Maven build with net.ltgt.gwt.maven:gwt-maven-plugin
> ----

> 
> Any insights or best practices for structuring GWT modules across Maven projects would be really helpful.

See https://tbroyer.github.io/gwt-maven-plugin/ and https://tbroyer.github.io/gwt-maven-plugin/usage.html

For a client-only library, use `<packaging>gwt-lib</packaging>`, and then depend on it using <type>gwt-lib</type> for better running/debugging support: https://tbroyer.github.io/gwt-maven-plugin/codeserver.html