Question

我需要使用Spring Batch编写稍微复杂的XML。有谁能帮助我使用适当的Spring配置？

以下是流程所需的输出。

<XML>
<USERLIST ID="something" NAME="Sample">
  <USER ID="userID" NAME="Name"/>
  <USER ID="userID" NAME="Name"/>
  ........
</USERLIST>
<XML>

＆＃39; UserList＆＃39;在上面的XML中只需要发生一次

这是我到目前为止的弹簧配置。

<bean id="userXMLWriter" class="org.springframework.batch.item.xml.StaxEventItemWriter">
    <property name="resource" value="file:outputs/users.xml" />
    <property name="encoding" value="ISO-8859-1" />
    <property name="version" value="1.0" />
    <property name="marshaller" ref="userXMLMarshaller" />
    <property name="rootTagName" value="XML" />
  </bean>

  <bean id="userXMLMarshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
  <property name="marshallerProperties">
        <map>
            <entry>
                <key>
                    <util:constant static-field="javax.xml.bind.Marshaller.JAXB_FORMATTED_OUTPUT" />
               </key>
              <value type="java.lang.Boolean">true</value>
            </entry>
        </map>
    </property>
    <property name="classesToBeBound">
    <list>
        <value>org.test.model.xml.UserList</value>
        <value>org.test.model.xml.User</value>
    </list>
    </property>
  </bean>

显然，当我测试这个时，我的XML没有＆＃39; USERLIST＆＃39;因为所有这些USER对象都需要在某处添加到USERLIST中。我是Spring Batch和JAXB2的新手。对此有任何想法表示赞赏。

谢谢，哈里什

Answer 1

解决这个问题的方法是实现Spring提供的Header / Footer Callback类（正如Michael Minella在下面的评论中所建议的那样<。strong>。），在我的案例中是StaxWriterCallback类。以下是我如何实施它。

<bean id="userXMLWriter" class="org.springframework.batch.item.xml.StaxEventItemWriter"> <property name="resource" value="file:outputs/users.xml" /> <property name="encoding" value="ISO-8859-1" /> <property name="version" value="1.0" /> <property name="marshaller" ref="userXMLMarshaller" /> <property name="headerCallback" ref="UserXMLHeaderCallBack" /> <property name="footerCallback" ref="UserXMLFooterCallBack"/> <property name="rootTagName" value="XML" /> </bean> <bean id="UserXMLHeaderCallBack" class ="org.test.writers.UserXMLHeaderCallBack"/> <bean id="UserXMLFooterCallBack" class ="org.test.writers.UserXMLFooterCallBack"/> <bean id="userXMLMarshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller"> <property name="classesToBeBound"> <list> <value>org.test.model.xml.User</value> </list> </property> </bean>

以下是Footer / Header回调类实现

public class UserXMLHeaderCallBack implements StaxWriterCallback{ @Override public void write(XMLEventWriter writer) throws IOException { try{ XMLEventFactory eventFactory = XMLEventFactory.newInstance(); Attribute id = eventFactory.createAttribute("ID", "someId"); Attribute name = eventFactory.createAttribute("NAME", "someName"); List<Attribute> attributeList = Arrays.asList(id, name); List<?> nsList = Arrays.asList(); XMLEvent event = eventFactory.createStartElement("", "", "USERLIST",attributeList.iterator(), nsList.iterator()); writer.add(event); }catch(XMLStreamException e){ System.err.println("Something went nuts!!!"); } } }

页脚类

public class UserXMLFooterCallBack implements StaxWriterCallback{ @Override public void write(XMLEventWriter writer) throws IOException { try{ XMLEventFactory eventFactory = XMLEventFactory.newInstance(); XMLEvent event = eventFactory.createEndElement("", "", "USERLIST"); writer.add(event); }catch(XMLStreamException e){ System.err.println("Something went nuts!!!"); } } }

我得到了所需的输出！

使用Spring Batch的复杂XML; StaxEventItemWriter; Jaxb2Marshaller

1 个答案: