spring singleton 豆结构

Question

I'm new on spring and I want a spring singleton bean to be created when the web application starts, not when it is referenced. Is there a way to achive this? Thanks in advance

Answer 1

This is the default behaviour. Spring beans are non-lazy singletons by default.

Answer 2

<bean id="Example" class="com.domain.Example" singleton="true" lazy-init="false" />

or

<bean id="Example" class="com.domain.Example" />

lazy-init and singleton are set to this value by default.

Answer 3

You could write a bootstrap class to load the reference on app start-up.

Answer 4

You can load your context by creating a servlet mapping in your web.xml file if you use Spring MCV

<servlet-mapping>
  <servlet-name>MyServlet<servlet-name>
  <url-pattern>*.jsp</url-pattern>
</servlet-mapping>

Next, load the configuration files. To do this, register the ContextLoaderListener. The ContextLoaderServlet will load the Spring configuration files when you start the Web application

<servlet>
  <servlet-name>context>servlet-name>
  <servlet-class>org.springframework.web.context.ContextLoaderServlet</servlet-class>
  <load-on-startup>1</load-on-startup>
</servlet>

The contextConfigLocation parameter defines the Spring configurations files to load

<context-param>
   <param-value>contextConfigLocation</param-value>
   <param-value>/WEB-INF/my-spring-config.xml</param-value>
 </context-param>