## org.springframework.web.servlet.view
Class InternalResourceView

    java.lang.Object
      org.springframework.context.support.ApplicationObjectSupport
          org.springframework.web.context.support.WebApplicationObjectSupport
              org.springframework.web.servlet.view.AbstractView
                  org.springframework.web.servlet.view.AbstractUrlBasedView
                      org.springframework.web.servlet.view.InternalResourceView

All Implemented Interfaces:
  BeanNameAware, InitializingBean, ApplicationContextAware, ServletContextAware, View

Direct Known Subclasses:
  JstlView, TilesView

    public class InternalResourceView

extends AbstractUrlBasedView

Wrapper for a JSP or other resource within the same web application. Exposes model objects as request attributes and forwards the request to the specified resource URL using a `RequestDispatcher`.

A URL for this view is supposed to specify a resource within the web application, suitable for RequestDispatcher's `forward` or `include` method.

If operating within an already included request or within a response that has already been committed, this view will fall back to an include instead of a forward. This can be enforced by calling `response.flushBuffer()` (which will commit the response) before rendering the view.

Typical usage with `InternalResourceViewResolver` looks as follows, from the perspective of the DispatcherServlet context definition:

    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
       <property name="prefix" value="/WEB-INF/jsp/"/>
       <property name="suffix" value=".jsp"/>
     </bean>

Every view name returned from a handler will be translated to a JSP resource (for example: "myView" -> "/WEB-INF/jsp/myView.jsp"), using this view class by default.

Author:
  Rod Johnson, Juergen Hoeller, Rob Harrop
See Also:
  `RequestDispatcher.forward(javax.servlet.ServletRequest, javax.servlet.ServletResponse)`, `RequestDispatcher.include(javax.servlet.ServletRequest, javax.servlet.ServletResponse)`, `ServletResponse.flushBuffer()`, `InternalResourceViewResolver`, `JstlView`

Field Summary

Fields inherited from class org.springframework.web.servlet.view.AbstractView
`DEFAULT_CONTENT_TYPE`

Fields inherited from class org.springframework.context.support.ApplicationObjectSupport
`logger`

Constructor Summary
`InternalResourceView()` Constructor for use as a bean.
`InternalResourceView(String url)` Create a new InternalResourceView with the given URL.
`InternalResourceView(String url, boolean alwaysInclude)` Create a new InternalResourceView with the given URL.

Method Summary
`protected void` `exposeForwardRequestAttributes(HttpServletRequest request)` Expose the current request URI and paths as `HttpServletRequest` attributes under the keys defined in the Servlet 2.4 specification, for Servlet 2.3 containers as well as misbehaving Servlet 2.4 containers (such as OC4J).
`protected void` `exposeHelpers(HttpServletRequest request)` Expose helpers unique to each rendering operation.
`protected HttpServletRequest` `getRequestToExpose(HttpServletRequest originalRequest)` Get the request handle to expose to the RequestDispatcher, i.e. to the view.
`protected void` `initServletContext(ServletContext sc)` Checks whether we need explictly expose the Servlet 2.4 request attributes by default.
`protected boolean` `isContextRequired()` An ApplicationContext is not strictly required for InternalResourceView.
`protected String` `prepareForRendering(HttpServletRequest request, HttpServletResponse response)` Prepare for rendering, and determine the request dispatcher path to forward to (or to include).
`protected void` `renderMergedOutputModel(Map model, HttpServletRequest request, HttpServletResponse response)` Render the internal resource given the specified model.
`void` `setAlwaysInclude(boolean alwaysInclude)` Specify whether to always include the view rather than forward to it.
`void` `setExposeContextBeansAsAttributes(boolean exposeContextBeansAsAttributes)` Set whether to make all Spring beans in the application context accessible as request attributes, through lazy checking once an attribute gets accessed.
`void` `setExposedContextBeanNames(String[] exposedContextBeanNames)` Specify the names of beans in the context which are supposed to be exposed.
`void` `setExposeForwardAttributes(boolean exposeForwardAttributes)` Set whether to explictly expose the Servlet 2.4 forward request attributes when forwarding to the underlying view resource.
`void` `setPreventDispatchLoop(boolean preventDispatchLoop)` Set whether to explicitly prevent dispatching back to the current handler path.
`protected boolean` `useInclude(HttpServletRequest request, HttpServletResponse response)` Determine whether to use RequestDispatcher's `include` or `forward` method.

Methods inherited from class org.springframework.web.servlet.view.AbstractUrlBasedView
`afterPropertiesSet, getUrl, isUrlRequired, setUrl, toString`

Methods inherited from class org.springframework.web.servlet.view.AbstractView
`addStaticAttribute, createRequestContext, createTemporaryOutputStream, exposeModelAsRequestAttributes, generatesDownloadContent, getAttributesMap, getBeanName, getContentType, getRequestContextAttribute, getStaticAttributes, prepareResponse, render, setAttributes, setAttributesCSV, setAttributesMap, setBeanName, setContentType, setRequestContextAttribute, writeToResponse`

Methods inherited from class org.springframework.web.context.support.WebApplicationObjectSupport
`getServletContext, getTempDir, getWebApplicationContext, initApplicationContext, setServletContext`

Methods inherited from class org.springframework.context.support.ApplicationObjectSupport
`getApplicationContext, getMessageSourceAccessor, initApplicationContext, requiredContextClass, setApplicationContext`

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait`

Constructor Detail

### InternalResourceView

    public InternalResourceView()

  Constructor for use as a bean.

  See Also:
    `AbstractUrlBasedView.setUrl(java.lang.String)`, `setAlwaysInclude(boolean)`

### InternalResourceView

    public InternalResourceView(String url)

  Create a new InternalResourceView with the given URL.

  Parameters:
    `url` - the URL to forward to
  See Also:
    `setAlwaysInclude(boolean)`

### InternalResourceView

    public InternalResourceView(String url,
                                boolean alwaysInclude)

  Create a new InternalResourceView with the given URL.

  Parameters:
    `url` - the URL to forward to
    `alwaysInclude` - whether to always include the view rather than forward to it

Method Detail

### setAlwaysInclude

    public void setAlwaysInclude(boolean alwaysInclude)

  Specify whether to always include the view rather than forward to it.

  Default is "false". Switch this flag on to enforce the use of a Servlet include, even if a forward would be possible.

  See Also:
    `RequestDispatcher.forward(javax.servlet.ServletRequest, javax.servlet.ServletResponse)`, `RequestDispatcher.include(javax.servlet.ServletRequest, javax.servlet.ServletResponse)`, `useInclude(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)`

### setExposeForwardAttributes

    public void setExposeForwardAttributes(boolean exposeForwardAttributes)

  Set whether to explictly expose the Servlet 2.4 forward request attributes when forwarding to the underlying view resource.

  Default is "true" on Servlet containers up until 2.4, and "false" for Servlet 2.5 and above. Note that Servlet containers at 2.4 level and above should expose those attributes automatically! This InternalResourceView feature exists for Servlet 2.3 containers and misbehaving 2.4 containers.

### setExposeContextBeansAsAttributes

    public void setExposeContextBeansAsAttributes(boolean exposeContextBeansAsAttributes)

  Set whether to make all Spring beans in the application context accessible as request attributes, through lazy checking once an attribute gets accessed.

  This will make all such beans accessible in plain `${...}` expressions in a JSP 2.0 page, as well as in JSTL's `c:out` value expressions.

  Default is "false". Switch this flag on to transparently expose all Spring beans in the request attribute namespace.

  NOTE: Context beans will override any custom request or session attributes of the same name that have been manually added. However, model attributes (as explicitly exposed to this view) of the same name will always override context beans.

  See Also:
    `getRequestToExpose(javax.servlet.http.HttpServletRequest)`

### setExposedContextBeanNames

    public void setExposedContextBeanNames(String[] exposedContextBeanNames)

  Specify the names of beans in the context which are supposed to be exposed. If this is non-null, only the specified beans are eligible for exposure as attributes.

  If you'd like to expose all Spring beans in the application context, switch the `"exposeContextBeansAsAttributes"` flag on but do not list specific bean names for this property.

### setPreventDispatchLoop

    public void setPreventDispatchLoop(boolean preventDispatchLoop)

  Set whether to explicitly prevent dispatching back to the current handler path.

  Default is "false". Switch this to "true" for convention-based views where a dispatch back to the current handler path is a definitive error.

### isContextRequired

    protected boolean isContextRequired()

  An ApplicationContext is not strictly required for InternalResourceView.

  Overrides:
    `isContextRequired` in class `WebApplicationObjectSupport`
  See Also:
    `ApplicationObjectSupport.getApplicationContext()`, `ApplicationObjectSupport.getMessageSourceAccessor()`, `WebApplicationObjectSupport.getWebApplicationContext()`, `WebApplicationObjectSupport.getServletContext()`, `WebApplicationObjectSupport.getTempDir()`

### initServletContext

    protected void initServletContext(ServletContext sc)

  Checks whether we need explictly expose the Servlet 2.4 request attributes by default.

  Overrides:
    `initServletContext` in class `WebApplicationObjectSupport`
  Parameters:
    `sc` - the ServletContext that this application object runs in (never `null`)
  See Also:
    `setExposeForwardAttributes(boolean)`, `exposeForwardRequestAttributes(javax.servlet.http.HttpServletRequest)`

### renderMergedOutputModel

    protected void renderMergedOutputModel(Map model,
                                           HttpServletRequest request,
                                           HttpServletResponse response)
                                    throws Exception

  Render the internal resource given the specified model. This includes setting the model as request attributes.

  Specified by:
    `renderMergedOutputModel` in class `AbstractView`
  Parameters:
    `model` - combined output Map (never `null`), with dynamic values taking precedence over static attributes
    `request` - current HTTP request
    `response` - current HTTP response
  Throws:
    `Exception` - if rendering failed

### exposeHelpers

    protected void exposeHelpers(HttpServletRequest request)
                          throws Exception

  Expose helpers unique to each rendering operation. This is necessary so that different rendering operations can't overwrite each other's contexts etc.

  Called by `renderMergedOutputModel(Map, HttpServletRequest, HttpServletResponse)`. The default implementation is empty. This method can be overridden to add custom helpers as request attributes.

  Parameters:
    `request` - current HTTP request
  Throws:
    `Exception` - if there's a fatal error while we're adding attributes
  See Also:
    `renderMergedOutputModel(java.util.Map, javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)`, `JstlView.exposeHelpers(javax.servlet.http.HttpServletRequest)`, `TilesJstlView.exposeHelpers(javax.servlet.http.HttpServletRequest)`

### prepareForRendering

    protected String prepareForRendering(HttpServletRequest request,
                                         HttpServletResponse response)
                                  throws Exception

  Prepare for rendering, and determine the request dispatcher path to forward to (or to include).

  This implementation simply returns the configured URL. Subclasses can override this to determine a resource to render, typically interpreting the URL in a different manner.

  Parameters:
    `request` - current HTTP request
    `response` - current HTTP response
  Returns:
    the request dispatcher path to use
  Throws:
    `Exception` - if preparations failed
  See Also:
    `AbstractUrlBasedView.getUrl()`, `TilesView.prepareForRendering(javax.servlet.http.HttpServletRequest, javax.servlet.http.HttpServletResponse)`

### getRequestToExpose

    protected HttpServletRequest getRequestToExpose(HttpServletRequest originalRequest)

  Get the request handle to expose to the RequestDispatcher, i.e. to the view.

  The default implementation wraps the original request for exposure of Spring beans as request attributes (if demanded).

  Parameters:
    `originalRequest` - the original servlet request as provided by the engine
  Returns:
    the wrapped request, or the original request if no wrapping is necessary
  See Also:
    `setExposeContextBeansAsAttributes(boolean)`, `ContextExposingHttpServletRequest`

### useInclude

    protected boolean useInclude(HttpServletRequest request,
                                 HttpServletResponse response)

  Determine whether to use RequestDispatcher's `include` or `forward` method.

  Performs a check whether an include URI attribute is found in the request, indicating an include request, and whether the response has already been committed. In both cases, an include will be performed, as a forward is not possible anymore.

  Parameters:
    `request` - current HTTP request
    `response` - current HTTP response
  Returns:
    `true` for include, `false` for forward
  See Also:
    `RequestDispatcher.forward(javax.servlet.ServletRequest, javax.servlet.ServletResponse)`, `RequestDispatcher.include(javax.servlet.ServletRequest, javax.servlet.ServletResponse)`, `ServletResponse.isCommitted()`, `WebUtils.isIncludeRequest(javax.servlet.ServletRequest)`

### exposeForwardRequestAttributes

    protected void exposeForwardRequestAttributes(HttpServletRequest request)

  Expose the current request URI and paths as `HttpServletRequest` attributes under the keys defined in the Servlet 2.4 specification, for Servlet 2.3 containers as well as misbehaving Servlet 2.4 containers (such as OC4J).

  Does not expose the attributes on Servlet 2.5 or above, mainly for GlassFish compatibility (GlassFish gets confused by pre-exposed attributes). In any case, Servlet 2.5 containers should finally properly support Servlet 2.4 features, shouldn't they...

  Parameters:
    `request` - current HTTP request
  See Also:
    `WebUtils.exposeForwardRequestAttributes(javax.servlet.http.HttpServletRequest)`

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