applicationContext object in JSP
How to configur开发者_开发问答e in my spring project to retrieve the applicationContext object in jsp using JSTL.
<%@page import="org.springframework.web.context.WebApplicationContext"%>
<%@page import="org.springframework.web.context.support.WebApplicationContextUtils"%>
<%
WebApplicationContext context = WebApplicationContextUtils
.getWebApplicationContext(application);
%>
application is the JSP defined ServletContext.
If you want to retrieve a bean and use JSTL, you can then do something like:
<%pageContext.setAttribute("bean", context.getBean("myBean"));%>
<c:out value="${bean.property}"/>
But, just because you can, doesn't mean you should. If you are doing anything more than displaying a bean's property you probably want to put this in a Servlet or some other controller.
Also, you do not want to be using the ApplicationContext as a way to pass beans between your controllers and views.
Spring root web application context is available in servlet context attribute named: org.springframework.web.context.WebApplicationContext.ROOT:
${applicationScope['org.springframework.web.context.WebApplicationContext.ROOT']}
Haven't tried it, but should be accessible via JSTL. But what you want to achieve? Is JSP really a good place to fetch beans manually and perform some business operations? Shouldn't you do all the work in servlet/controller and let JSP do only the view, as it was intended?
EDIT: I was worng, it doesn't work. Anyway, you would be able to access all beans by name, with no need of ApplicationContext, depending on what you need to do.
.
If you set property exposeContextBeansAsAttributes of InternalResourceViewResolver to true, you would be able to access from JSP using EL: ${applicationContext}. Depending of what you're trying to do, this can be more or less suitable.
EDIT: Your view resolver for JSP must be something similar to:
<bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<property name="viewClass" value="org.springframework.web.servlet.view.JstlView" />
<property name="prefix" value="/WEB-INF/views/" />
<property name="suffix" value=".jsp" />
<property name="exposeContextBeansAsAttributes" value="true" />
</bean>
The best thing is that you can get the bean you want by its name. So, probably, you won't need ApplicationContext there.
For Spring 4 it works well:
<%
ApplicationContext context = RequestContextUtils.findWebApplicationContext(request);
%>
Well, with spring-boot 2.1.5.RELEASE I am allowed to do these:
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<%@ taglib prefix="spring" uri="http://www.springframework.org/tags" %>
thumbs.dir: <spring:eval expression="@environment.getProperty('thumbs.dir')"/><br>
users.file: <spring:eval expression="@environment.getProperty('users.file')"/><br>
jdbc.url: <spring:eval expression="@jdbcProperties.jdbcUrl"/><br>
<spring:eval expression="@jdbcProperties" var="jdbcProperties"/>
<c:if test="${empty jdbcProperties}">jdbcProperties is empty<br></c:if>
<c:if test="${!empty jdbcProperties}">jdbc.username: ${jdbcProperties.username}<br></c:if>
where @jdbcProperties is this spring bean:
@Bean("jdbcProperties")
public Properties stageDsProperties() throws IOException {
return PropertiesLoaderUtils.loadAllProperties("jdbc-datasource/jdbc-stage.properties");
}
Here's what worked for me, hoping this helps someone else since it took me quite some time to figure out. Building on Pavel Vlasov's answer:
<% ApplicationContext context = RequestContextUtils.findWebApplicationContext(request); %>
<% pageContext.setAttribute("myKey", context.getBean("myObject")); %>
And then further down my JSP page I have
<body>
<div>
<%
MyObject coolObject = (MyObject)pageContext.getAttribute("myKey");
coolObject.doSomething();
%>
</div>
</body>
加载中,请稍侯......
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