How do I generate equals and hashCode with the CXF xjcplugin

Question

I am trying to generate a Java class containing the methods toString, equals and hashCode from an XSD file. I got toString working, but I am not able to figure out how to get the CXF plugin to generate the equals and the hashCode methods.

This is my XSD file :

<?xml version="1.0" encoding="utf-8"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" targetNamespace="http://www.example.com/messagedefinitions"
           xmlns="http://www.example.com/messagedefinitions">


    <xs:element name="Message">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="status" type="Status"/>
                <xs:element name="id" type="Identifier"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

    <xs:simpleType name="Status">
        <xs:restriction base="xs:string">
            <xs:maxLength value="4"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="Identifier">
        <xs:restriction base="xs:int"/>
    </xs:simpleType>

</xs:schema>

My working POM (what does not work is commented out) :

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>xsd-demo</artifactId>
    <version>1.0-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>xsd-demo</name>
    <url>http://maven.apache.org</url>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <cxf.version>2.6.1</cxf.version>
        <cxf.xjc.plugin.version>2.6.1</cxf.xjc.plugin.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.apache.cxf</groupId>
            <artifactId>cxf-tools-common</artifactId>
            <version>${cxf.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.cxf.xjc-utils</groupId>
            <artifactId>xjc-utils</artifactId>
            <type>pom</type>
            <version>${cxf.xjc.plugin.version}</version>
        </dependency>
        <dependency>
            <groupId>org.apache.cxf.xjc-utils</groupId>
            <artifactId>cxf-xjc-runtime</artifactId>
            <version>${cxf.xjc.plugin.version}</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <inherited>true</inherited>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <version>3.1</version>
                <configuration>
                    <source>1.7</source>
                    <target>1.7</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.cxf</groupId>
                <artifactId>cxf-xjc-plugin</artifactId>
                <version>${cxf.xjc.plugin.version}</version>
                <executions>
                    <execution>
                        <id>generate-sources</id>
                        <phase>generate-sources</phase>
                        <goals>
                            <goal>xsdtojava</goal>
                        </goals>

                        <configuration>
                            <sourceRoot>${basedir}/target/generated-sources</sourceRoot>
                            <xsdOptions>
                                <xsdOption>
                                    <extension>true</extension>
                                    <xsd>${basedir}/src/main/resources/xsd/Message.xsd</xsd>
                                    <bindingFile>${basedir}/src/main/resources/bindings.xml</bindingFile>
                                    <extensionArgs>
                                        <arg>-Xts:style:multiline</arg>
                                        <!--<arg>-Xequals</arg>-->
                                        <!--<arg>-XhashCode</arg>-->
                                    </extensionArgs>
                                </xsdOption>
                            </xsdOptions>
                            <extensions>
                                <extension>org.apache.cxf.xjcplugins:cxf-xjc-ts:${cxf.xjc.plugin.version}</extension>
                                <!--<extension>org.apache.cxf.xjcplugins:cxf-xjc-XhashCode:${cxf.xjc.plugin.version}-->
                                <!--</extension>-->
                                <!--<extension>org.apache.cxf.xjcplugins:cxf-xjc-Xequals:${cxf.xjc.plugin.version}-->
                                <!--</extension>-->
                            </extensions>
                        </configuration>
                    </execution>
                </executions>
            </plugin>
        </plugins>
    </build>

</project>

The bindings file :

<?xml version="1.0" encoding="UTF-8"?>
<jaxb:bindings
        xmlns:jaxb="http://java.sun.com/xml/ns/jaxb"
        xmlns:xjc="http://java.sun.com/xml/ns/jaxb/xjc"
        jaxb:version="2.1">
    <jaxb:globalBindings>
        <xjc:serializable uid="1234"/>
    </jaxb:globalBindings>
</jaxb:bindings>

If I un-comment the commented-out lines for the Xequals I get this error :

[ERROR] Failed to execute goal org.apache.cxf:cxf-xjc-plugin:2.6.1:xsdtojava (generate-sources) on project xsd-demo: Could not download extension artifact: Requested download does not exist. Could not find artifact org.apache.cxf.xjcplugins:cxf-xjc-Xequals:jar:2.6.1 in central (http://repo1.maven.org/maven2)

Fine, I realise that the artifact does not exist, but I do not know then how to configure the CXF plugin to generate the equals and hashCode methods. Do you know how I can configure the CXF plugin to generate the equals and hashCode methods ? Thanks in advance for any help.

Answer 1

This download (zip) is a stand-alone Maven project to demonstrate the configuration of the Maven cxf-xjc-plugin from Apache CXF together with the XJC HiSrc BasicJAXB Plugins. Specifically, it configures the following XJC plugins:

• -XhashCode - generate reflection-free hashCode methods.
• -Xequals - generate reflection-free equals methods.
• -XtoString - generate reflection-free toString methods.
• -xfluentAPI - enable Fluent API, method chaining, for generated code.

Note: After extracting the download to your local folder, you can run the tests and/or the demo using:

mvn -Ptest clean test
mvn -Pexec compile exec:java

Business Model

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    targetNamespace="http://www.example.com/messagedefinitions"
    xmlns="http://www.example.com/messagedefinitions"
>

    <xs:element name="Message">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="status" type="Status"/>
                <xs:element name="id" type="Identifier"/>
            </xs:sequence>
        </xs:complexType>
    </xs:element>

    <xs:simpleType name="Status">
        <xs:restriction base="xs:string">
            <xs:maxLength value="4"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="Identifier">
        <xs:restriction base="xs:int"/>
    </xs:simpleType>

</xs:schema>

By default, XJC generates a JAXB class for each of the above elements using the Object hashCode, equals and toString methods. At this level, objects are compared by object id. To compare/evaluate the JAXB generated Message objects by value, the HiSrc BasicJAXB Plugins are configured as <extensionArgs> in the cxf-xjc-plugin.

<extensionArgs>
    <extensionArg>-no-header</extensionArg>
    <extensionArg>-XhashCode</extensionArg>
    <extensionArg>-Xequals</extensionArg>
    <extensionArg>-XtoString</extensionArg>
    <extensionArg>-XfluentAPI</extensionArg>
    <extensionArg>-XfluentAPI-fluentMethodPrefix=use</extensionArg>
</extensionArgs>

For unit testing, the -XfluentAPI plugin, is also activated, to facilitate the setting of a test instance of the Message object.

FluentAPITest

final Object object = getUnmarshaller().unmarshal(sample);
if ( object instanceof Message )
{
    Message msi1 = (Message) object;
    Message msi2 = OF.createMessage()
        .useStatus("PASS")
        .useId(1001);

    getLogger().debug("MSI1: {}", msi1);
    getLogger().debug("MSI2: {}", msi2);

    assertEquals(msi1, msi2, "Unmarshaled and Fluent MSIs are equal.");
}

JAR Conflicts

The cxf-xjc-plugin above explicitly declares several dependencies (not shown) to resolve JAR conflicts between the CXF product and the HiSrc product. Because these products are produced by independent teams, some version conflicts are likely. The download (zip) contains a tool, named ReadJarManifest.java to identify and resolve conflicts. The conflicts have been resolved in the download sample.

Generate build.log

mvn -Dorg.slf4j.simpleLogger.log.org.apache.cxf.maven_plugin.XSDToJavaMojo=DEBUG -Ptest clean test >build.log

ReadJarManifest.java

Read JAR Manifest from a JAR file or a LOG file.

Usage:
    javac ReadJarManifest.java
    java ReadJarManifest [jarfile | stdin]

Example:
    java ReadJarManifest <build.log

Note: The ReadJarManifest.java tool catches most issues but can also report false conflicts. In this example, the conflict percentage is falsely high because two non-conflicting jars have the same version number but different yet similar names.

Conflict%: 89
  file:/home/rick/.m2/repository/org/glassfish/jaxb/txw2/4.0.5/txw2-4.0.5.jar
  file:/home/rick/.m2/repository/org/glassfish/jaxb/xsom/4.0.5/xsom-4.0.5.jar

Disclaimer: I am the maintainer of the HiSrc projects.

Answer 2

Surely too late for you...but...

I managed to generate hashcode and equals with the plugin cxf-xjc-plugin (as in the question) with org.jvnet.jaxb2_commons:jaxb2-basics:0.7.0

You need org.jvnet.jaxb2_commons:jaxb2-basics:0.7.0 to generate the methods (equals, hashcode) and org.jvnet.jaxb2_commons:jaxb2-basics-runtime:0.7.0 for compilation dependencies

The use of antrun is ugly but i need it to generate a directory for my episode The use of build-helper-maven-plugin is to add generated directory to classpath in eclipse I use a binding file (change it if necessary)

    <dependencies>
    <dependency>
        <groupId>org.apache.cxf.xjcplugins</groupId>
        <artifactId>cxf-xjc-ts</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.cxf.xjc-utils</groupId>
        <artifactId>cxf-xjc-runtime</artifactId>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
    </dependency>
    <dependency>
        <groupId>org.jvnet.jaxb2_commons</groupId>
        <artifactId>jaxb2-basics-runtime</artifactId>
    </dependency>
    <dependency>
        <groupId>org.jvnet.jaxb2_commons</groupId>
        <artifactId>jaxb2-basics</artifactId>
    </dependency>
</dependencies>

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-antrun-plugin</artifactId>
            <executions>
                <execution>
                    <id>generate-resources</id>
                    <phase>validate</phase>
                    <goals>
                        <goal>run</goal>
                    </goals>
                    <configuration>
                        <tasks>
                            <echo message="Creating directories" />
                            <mkdir dir="./target/generated/src/main/resources/bindings/" />
                        </tasks>
                    </configuration>
                </execution>
            </executions>
        </plugin>
        <plugin>
            <groupId>org.codehaus.mojo</groupId>
            <artifactId>build-helper-maven-plugin</artifactId>
            <executions>
                <execution>
                    <id>add-source</id>
                    <phase>generate-sources</phase>
                    <goals>
                        <goal>add-source</goal>
                    </goals>
                    <configuration>
                        <sources>
                            <source>${basedir}/target/generated/src/main/java/</source>
                        </sources>
                    </configuration>
                </execution>
                <execution>
                    <id>add-resource</id>
                    <phase>generate-sources</phase>
                    <goals>
                        <goal>add-resource</goal>
                    </goals>
                    <configuration>
                        <resources>
                            <resource>
                                <directory>
                                    ${basedir}/target/generated/src/main/resources/bindings/</directory>
                            </resource>
                        </resources>
                    </configuration>
                </execution>
            </executions>
        </plugin>
        <plugin>
            <groupId>org.apache.cxf</groupId>
            <artifactId>cxf-xjc-plugin</artifactId>
            <configuration>
                <extensions>
                    <extension>org.apache.cxf.xjcplugins:cxf-xjc-dv:3.0.3</extension>
                    <extension>org.apache.cxf.xjcplugins:cxf-xjc-ts:3.0.3</extension>
                    <extension>org.jvnet.jaxb2_commons:jaxb2-basics:0.7.0</extension>
                </extensions>
            </configuration>
            <executions>
                <execution>
                    <id>generate-sources</id>
                    <phase>generate-sources</phase>
                    <goals>
                        <goal>xsdtojava</goal>
                    </goals>
                    <configuration>
                        <xsdOptions>
                            <xsdOption>
                                <extension>true</extension>
                                <xsd>${basedir}/src/main/resources/schemas/FluxExportDenormalized.xsd</xsd>
                                <bindingFile>${basedir}/src/main/resources/bindings/binding.xjb</bindingFile>
                                <extensionArgs>
                                    <extensionArg>-Xdv</extensionArg>
                                    <extensionArg>-episode</extensionArg>
                                    <extensionArg>${basedir}/target/generated/src/main/resources/bindings/FluxExportTarifDenormalized.episode</extensionArg>
                                    <extensionArg>-Xts</extensionArg>
                                    <extensionArg>-Xequals</extensionArg>
                                    <extensionArg>-XhashCode</extensionArg>
                                </extensionArgs>
                            </xsdOption>
                            <xsdOption>
                                <extension>true</extension>
                                <xsd>${basedir}/src/main/resources/schemas/FluxExportNormalized.xsd</xsd>
                                <extensionArgs>
                                    <extensionArg>-Xdv</extensionArg>
                                    <extensionArg>-b</extensionArg>
                                    <extensionArg>${basedir}/src/main/resources/bindings/binding.xjb</extensionArg>
                                    <extensionArg>-b</extensionArg>
                                    <extensionArg>${basedir}/target/generated/src/main/resources/bindings/FluxExportDenormalized.episode</extensionArg>
                                    <extensionArg>-Xequals</extensionArg>
                                    <extensionArg>-XhashCode</extensionArg>
                                </extensionArgs>
                            </xsdOption>
                        </xsdOptions>
                    </configuration>
                </execution>
            </executions>
            <dependencies>
                <dependency>
                    <groupId>org.jvnet.jaxb2_commons</groupId>
                    <artifactId>jaxb2-basics</artifactId>
                    <version>0.7.0</version>
                </dependency>
            </dependencies>
        </plugin>

Maybe you need the lifecycle in eclipse to avoid red cross error:

<?xml version="1.0" encoding="UTF-8"?>
<lifecycleMappingMetadata>
    <pluginExecutions>
        <pluginExecution>
            <pluginExecutionFilter>
                <groupId>org.apache.cxf</groupId>
                <artifactId>cxf-xjc-plugin</artifactId>
                <versionRange>[2.3.0,)</versionRange>
                <goals>
                    <goal>xsdtojava</goal>
                </goals>
            </pluginExecutionFilter>
            <action>
                <execute />
            </action>
        </pluginExecution>
        <pluginExecution>
            <pluginExecutionFilter>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-antrun-plugin</artifactId>
                <versionRange>[1.4,)</versionRange>
                <goals>
                    <goal>run</goal>
                </goals>
            </pluginExecutionFilter>
            <action>
                <execute />
            </action>
        </pluginExecution>
    </pluginExecutions>
</lifecycleMappingMetadata>

Answer 3

After reading this HOWTO, I got it to work like so:

<build>
   <plugins>
      <!-- Build WSDL resources (includes XSDs) -->
      <plugin>
         <groupId>org.apache.cxf</groupId>
         <artifactId>cxf-codegen-plugin</artifactId>
         <version>2.7.0</version>
         <executions>
            <execution>
               <id>generate-sources</id>
               <phase>generate-sources</phase>
               <goals>
                  <goal>wsdl2java</goal>
               </goals>
            </execution>
         </executions>
         <configuration>
            <defaultOptions>
               <extraargs>
                  <extraarg>-verbose</extraarg>
                  <extraarg>-xjc-Xequals</extraarg>
                  <extraarg>-xjc-XhashCode</extraarg>
               </extraargs>
               <bindingFiles>
                  <!-- Shared XSD file bindings -->
                  <bindingFile>${project.basedir}/src/main/resources/bindings.xjb</bindingFile>
               </bindingFiles>
            </defaultOptions>
            <wsdlOptions>
               <wsdlOption>
                  <wsdl>https://myserver.com/MyService?wsdl</wsdl>
                  <bindingFiles>
                     <!-- Specific WSDL file bindings -->
                     <bindingFile>${project.basedir}/src/main/resources/wsdl-bindings.xml</bindingFile>
                  </bindingFiles>
               </wsdlOption>
            </wsdlOptions>
         </configuration>
         <dependencies>
            <dependency>
               <groupId>org.jvnet.jaxb2_commons</groupId>
               <artifactId>jaxb2-basics</artifactId>
               <version>0.6.5</version>
            </dependency>
         </dependencies>
      </plugin>
   </plugins>
</build>

<dependencies>
   <!-- The generated equals and hashCode methods require some runtime libraries. -->
   <dependency>
      <groupId>org.jvnet.jaxb2_commons</groupId>
      <artifactId>jaxb2-basics-runtime</artifactId>
   </dependency>
</dependencies>

Unfortunately, for me, using the jvnet jaxws-maven-plugin is not an option, as our WSDL files are given to us by a 3rd party and they have issues (such as soap:body elements within wsdl:fault elements) which cause the standard plugin to choke.

Answer 4

I was not able to get the cxf-xjc-plugin to generate the equals and hashCode methods from the XML schema files. I gave up on the cxf-xjc-plugin and turned to the maven-jaxb2-plugin instead. This is the plugin configuration I used :

<plugin>
  <groupId>org.jvnet.jaxb2.maven2</groupId>
  <artifactId>maven-jaxb2-plugin</artifactId>
  <version>0.8.3</version>
  <executions>
    <execution>
      <id>generate</id>
      <phase>generate-sources</phase>
      <goals>
        <goal>generate</goal>
      </goals>
      <configuration>
        <extension>true</extension>
          <generatePackage>my.package.name</generatePackage>
          <args>
            <arg>-XtoString</arg>
            <arg>-Xequals</arg>
            <arg>-XhashCode</arg>
          </args>
          <schemaDirectory>${basedir}/src/main/resources</schemaDirectory>
          <schemaIncludes>
            <include>xsd/*.xsd</include>
          </schemaIncludes>
          <plugins>
            <plugin>
              <groupId>org.jvnet.jaxb2_commons</groupId>
              <artifactId>jaxb2-basics</artifactId>
              <version>0.6.4</version>
            </plugin>
          </plugins>
        </configuration>
      </execution>
  </executions>
</plugin>