Introduction to Spring - Spring Enterprise Recipes: A Problem Solution Approach - page 14

buffer.append("@");
buffer.append(entry.getValue());
}
return buffer.toString();
}
}
In Spring, a map is defined by the <map> tag, with multiple <entry> tags as children. Each entry
contains a key and a value. The key must be defined inside the <key> tag. There is no restriction on the
type of the key and value, so you are free to specify a <value> , <ref> , <bean> , <idref> , or <null> element
for them. Spring will also preserve the order of the map entries by using java.util.LinkedHashMap .
<bean id="sequenceGenerator"
class="com.apress.springenterpriserecipes.sequence.SequenceGenerator">
...
<property name="suffixes">
<map>
<entry>
<key>
<value>type</value>
</key>
<value>A</value>
</entry>
<entry>
<key>
<value>url</value>
</key>
<bean class="java.net.URL">
<constructor-arg value="http" />
<constructor-arg value=" www.apress.com" />
<constructor-arg value="/" />
</bean>
</entry>
</map>
</property>
</bean>
There are shortcuts to defining map keys and values as attributes of the <entry> tag. If they are
simple constant values, you can define them by key and value . If they are bean references, you can
define them by key-ref and value-ref .
<bean id="sequenceGenerator"
class="com.apress.springenterpriserecipes.sequence.SequenceGenerator">
...
<property name="suffixes">
<map>
<entry key="type" value="A" />
<entry key="url">
<bean class="java.net.URL">
<constructor-arg value="http" />
<constructor-arg value=" www.apress.com" />
<constructor-arg value="/" />
</bean>