Declaring Integers, Doubles, Floats, Strings etc. in Spring XML
Occasionally, Spring can't figure out what type a "value" should be. This happens when the property or constructor is of type "java.lang.Object". In these cases, Spring defaults to "java.lang.String". Sometimes this isn't the r开发者_StackOverflow社区ight choice, for example when using:
<jee:jndi-lookup id="test" jndi-name="java:comp/env/test"
default-value="10" expected-type="java.lang.Integer"/>
If the lookup fails and it has to fall back to the default-value, there's a type mismatch. So, instead, this needs to be done:
<bean id="test" class="org.springframework.jndi.JndiObjectFactoryBean">
<property name="jndiName" value="java:comp/env/test" />
<property name="defaultObject">
<bean class="java.lang.Integer">
<constructor-arg value="10" />
</bean>
</property>
</bean>
which is somewhat verbose, especially if there are lots of them. Is there some handy way to declare an Integer / Long / Double / Float / String literal without having to use this format:
<bean class="java.lang.Integer">
<constructor-arg value="10" />
</bean>
Since Spring 3.0, you can use Spring Expression Language: #{new Integer(10)}
<jee:jndi-lookup id="test" jndi-name="java:comp/env/test"
default-value="#{new Integer(10)}" expected-type="java.lang.Integer"/>
You should be able to do:
<constructor-arg value="10" type="int"/>
See section 3.3.1.1.1.1 of the Spring Reference
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