Spring IOC 注入集合
The?<list/>,?<set/>,?<map/>, and?<props/>?elements allow properties and arguments of the Java?Collection?type?List,?Set,?Map, and?Properties, respectively, to be defined and set.
<property name="adminEmails">
????<props>
????????<prop key="administrator">administrator@example.org</prop>
????????<prop key="support">support@example.org</prop>
????????<prop key="development">development@example.org</prop>
????</props>
??</property>
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前提：com.dao.impl.UserDAOImpl类中的sets lists maps集合，必须有set方法
<bean name="userDAO" value="1"></entry>
?????<entry key="2" value="2"></entry>
?????<entry key="3" value="3"></entry>
?????<entry key="4" value="4"></entry>
????</map>
???</property>
??</bean>
很少用，用于别人提供的类
