Unmarshalling collections in JaxB

Question

suppose I have this class:

public class A {

    private HashMap<String, B> map;

    @XmlElement
    private void setB(ArrayList<B> col) {
        ...
    }

    private ArrayList<B> getB() {
        ...
    }

}

When trying to unmarshall an xml document to this class using JaxB I notice that instead of calling the setB() method and sending me the list of B instances JaxB actually calls the getB() and adds the B instances to the returned list. Why?

The reason I want the setter to be called is that the list is actually just a temporary storage from which I want to build the map field, so I thought to do it in the setter.

Thanks.

Answer 1

thats the way jaxb is handling collections. you have to be sure you have a non null collection when jaxb try to unmarshal.

there is a plugin (never used it myself) but can be helpful: https://jaxb2-commons.dev.java.net/collection-setter-injector/

Answer 2

Hy,

you can use it with jaxb, it's work !!! (with Maven....)

<plugin>
            <groupId>org.jvnet.jaxb2.maven2</groupId>
            <artifactId>maven-jaxb2-plugin</artifactId>
            <executions>
                <execution>
                    <goals>
                        <goal>generate</goal>
                    </goals>
                </execution>
            </executions>
            <configuration>
                <args>
                    <arg>-Xcollection-setter-injector</arg>
                </args>
                <plugins>
                    <plugin>
                        <groupId>net.java.dev.vcc.thirdparty</groupId>
                        <artifactId>collection-setter-injector</artifactId>
                        <version>0.5.0-1</version>
                    </plugin>
                </plugins>
                <schemaDirectory>src/schemas</schemaDirectory>
                <generateDirectory>src/main/java</generateDirectory>
                <extension>true</extension>
            </configuration>
        </plugin>

and you get your setter for your Collection

Hope it would help people

bye