从Tiles视图（JSP）访问Spring bean [英] Accessing Spring beans from a Tiles view (JSP)

问题描述

在Spring MVC中，我可以使用JstlView的exposedContextBeanNames（或exposeContextBeansAsAttributes）在JSP中访问我的bean。例如，然后，在我的JSP中我可以编写（$ {properties.myProperty）。但是，当相同的JSP是切片视图的一部分时，无法访问这些属性。是否可以正确配置Tiles或以其他方式访问这些属性？

In Spring MVC I can access my beans in JSP using JstlView's exposedContextBeanNames (or exposeContextBeansAsAttributes). For example, then, in my JSP I can write (${properties.myProperty). But when the same JSP is a part of a tiles view, these properties aren't accessible. Is possible to configure Tiles properly or access these properties in another way?

我正在使用Spring MVC 3.0.2和Tiles 2.2.1。这是我的一些配置：

I'm using Spring MVC 3.0.2 and Tiles 2.2.1. Here's a bit of my configuration:

<bean id="tilesViewResolver" class="org.springframework.web.servlet.view.UrlBasedViewResolver">
    <property name="order" value="1"/>
    <property name="viewClass" value="org.springframework.web.servlet.view.tiles2.TilesView" />
</bean> 

<bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
    <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
    <property name="order" value="2"/>
    <property name="prefix" value="/WEB-INF/views/"/>
    <property name="suffix" value=".jsp"/>
    <property name="exposedContextBeanNames">
        <list><value>properties</value></list>
    </property>
</bean>

编辑：我已经实施了Skaffman的解决方案。

I've implemented Skaffman's solution.

TilesExposingBeansViewResolver.java：

TilesExposingBeansViewResolver.java:

package es.kcsolutions.util.spring.servlet.view;

import org.springframework.web.servlet.view.*;

public class TilesExposingBeansViewResolver extends UrlBasedViewResolver {

    private Boolean exposeContextBeansAsAttributes;
    private String[] exposedContextBeanNames;

    public void setExposeContextBeansAsAttributes(boolean exposeContextBeansAsAttributes) {
        this.exposeContextBeansAsAttributes = exposeContextBeansAsAttributes;
    }

    public void setExposedContextBeanNames(String[] exposedContextBeanNames) {
        this.exposedContextBeanNames = exposedContextBeanNames;
    }

    @Override
    protected AbstractUrlBasedView buildView(String viewName) throws Exception {
        AbstractUrlBasedView superView = super.buildView(viewName);
        if (superView instanceof TilesExposingBeansView) {
            TilesExposingBeansView view = (TilesExposingBeansView) superView;
            if (this.exposeContextBeansAsAttributes != null) view.setExposeContextBeansAsAttributes(this.exposeContextBeansAsAttributes);
            if (this.exposedContextBeanNames != null) view.setExposedContextBeanNames(this.exposedContextBeanNames);
        }
        return superView;
    }

}

TilesExposingBeansView.java：

TilesExposingBeansView.java:

package es.kcsolutions.util.spring.servlet.view;

import java.util.*;
import javax.servlet.http.*;
import org.springframework.web.context.support.ContextExposingHttpServletRequest;
import org.springframework.web.servlet.view.tiles2.TilesView;

public class TilesExposingBeansView extends TilesView {

    private boolean exposeContextBeansAsAttributes = false;
    private Set<String> exposedContextBeanNames;

    public void setExposeContextBeansAsAttributes(boolean exposeContextBeansAsAttributes) {
        this.exposeContextBeansAsAttributes = exposeContextBeansAsAttributes;
    }

    public void setExposedContextBeanNames(String[] exposedContextBeanNames) {
        this.exposedContextBeanNames = new HashSet<String>(Arrays.asList(exposedContextBeanNames));
    } 

    protected HttpServletRequest getRequestToExpose(HttpServletRequest originalRequest) {
        if (this.exposeContextBeansAsAttributes || this.exposedContextBeanNames != null) 
        return new ContextExposingHttpServletRequest(originalRequest, getWebApplicationContext(), this.exposedContextBeanNames);
        return originalRequest;
    }

    @Override
    protected void renderMergedOutputModel(Map<String, Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception {
        HttpServletRequest requestToExpose = getRequestToExpose(request);
        exposeModelAsRequestAttributes(model, requestToExpose);
        super.renderMergedOutputModel(model, requestToExpose, response);
    }

}

春季配置：

    <bean id="tilesViewResolver" class="es.kcsolutions.util.spring.servlet.view.TilesExposingBeansViewResolver">
        <property name="order" value="1"/>
        <property name="viewClass" value="es.kcsolutions.util.spring.servlet.view.TilesExposingBeansView"/>
        <property name="exposedContextBeanNames">
            <list><value>properties</value></list>
        </property>
    </bean> 

如果您遇到问题，请查看TilesExposingBeansView.renderMergedOutputModel。我做了一些测试，但也许有必要做更多。

If you have some problem, take a look at TilesExposingBeansView.renderMergedOutputModel. I've made some tests, but maybe it's necessary to make a lot more.

推荐答案

正如你所注意到的，这个功能是 InternalResourceViewResolver 和 InternalResourceView 的一部分，而Tiles的东西直接从 UrlBasedViewResolver 和 AbstractUrlBasedView ，所以你不能使用它。

As you've noticed, this functionality is part of InternalResourceViewResolver and InternalResourceView, whereas the Tiles stuff inherits directly from UrlBasedViewResolver and AbstractUrlBasedView, so you can't make use of it.

查看代码，没有理由为什么这些东西不能被放入 AbstractUrlBasedView 。神奇的事情发生在 InternalResourceView.getRequestToExpose ，它看起来完全适用于 AbstractUrlBasedView 。

Looking at the code, there's no reason why this stuff couldn't have been put into AbstractUrlBasedView. The magic happens in InternalResourceView.getRequestToExpose, and it looks perfectly applicable to AbstractUrlBasedView too.

在短期内，我建议继承 UrlBasedViewResolver 和 TilesView ，复制 getRequestToExpose 来自 InternalResourceView 的东西。从长远来看，我建议您向 SpringSource 提出问题，要求他们将此功能提升到类层次结构中进入 AbstractUrlBasedView ，使其更广泛地可用。

In the short term, I suggest subclassing UrlBasedViewResolver and TilesView, copying the getRequestToExpose stuff from InternalResourceView. In the longer term, I encourage you to file a issue with SpringSource asking them to move this functionality up the class hierarchy into AbstractUrlBasedView, making it more widely available.

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