org.springframework.web.servlet.view: public class: InternalResourceView

org.springframework.web.servlet.view
public class: InternalResourceView [javadoc | source]

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:
InitializingBean, View, BeanNameAware, ServletContextAware, ApplicationContextAware

Direct Known Subclasses:
TilesView, JstlView, TilesJstlView

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 javax.servlet.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.

Also see:

javax.servlet.RequestDispatcher#forward

javax.servlet.RequestDispatcher#include

javax.servlet.ServletResponse#flushBuffer

InternalResourceViewResolver

JstlView

author: Rod - Johnson

author: Juergen - Hoeller

author: Rob - Harrop

Fields inherited from org.springframework.web.servlet.view.AbstractView:
DEFAULT_CONTENT_TYPE

Fields inherited from org.springframework.context.support.ApplicationObjectSupport:
logger

Constructor:

Constructor:
public InternalResourceView() { } Constructor for use as a bean. Also see: setUrl setAlwaysInclude
public InternalResourceView(String url) { super(url); } Create a new InternalResourceView with the given URL. Parameters: `url` - the URL to forward to Also see: setAlwaysInclude
public InternalResourceView(String url, boolean alwaysInclude) { super(url); this.alwaysInclude = 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

 public InternalResourceView() {

}

Constructor for use as a bean.

Also see:

setUrl

setAlwaysInclude

 public InternalResourceView(String url) {
		super(url);
}

Create a new InternalResourceView with the given URL.

Parameters:

url - the URL to forward to

Also see:

setAlwaysInclude

 public InternalResourceView(String url,
    boolean alwaysInclude) {
		super(url);
		this.alwaysInclude = 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 from org.springframework.web.servlet.view.InternalResourceView Summary:
exposeForwardRequestAttributes, exposeHelpers, getRequestToExpose, initServletContext, isContextRequired, prepareForRendering, renderMergedOutputModel, setAlwaysInclude, setExposeContextBeansAsAttributes, setExposeForwardAttributes, setExposedContextBeanNames, setPreventDispatchLoop, useInclude

Methods from org.springframework.web.servlet.view.AbstractUrlBasedView:
afterPropertiesSet, getUrl, isUrlRequired, setUrl, toString

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

Methods from org.springframework.web.servlet.view.AbstractView:

addStaticAttribute, createRequestContext, createTemporaryOutputStream, exposeModelAsRequestAttributes, generatesDownloadContent, getAttributesMap, getBeanName, getContentType, getRequestContextAttribute, getStaticAttributes, prepareResponse, render, renderMergedOutputModel, setAttributes, setAttributesCSV, setAttributesMap, setBeanName, setContentType, setRequestContextAttribute, toString, writeToResponse

Methods from org.springframework.web.context.support.WebApplicationObjectSupport:
getServletContext, getTempDir, getWebApplicationContext, initApplicationContext, initServletContext, isContextRequired, setServletContext

Methods from org.springframework.context.support.ApplicationObjectSupport:
getApplicationContext, getMessageSourceAccessor, initApplicationContext, initApplicationContext, isContextRequired, requiredContextClass, setApplicationContext

Methods from java.lang.Object:
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method from org.springframework.web.servlet.view.InternalResourceView Detail:
protected void exposeForwardRequestAttributes(HttpServletRequest request) { if (this.exposeForwardAttributes != null && this.exposeForwardAttributes.booleanValue()) { WebUtils.exposeForwardRequestAttributes(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...
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.
protected HttpServletRequest getRequestToExpose(HttpServletRequest originalRequest) { if (this.exposeContextBeansAsAttributes \|\| this.exposedContextBeanNames != null) { return new ContextExposingHttpServletRequest( originalRequest, getWebApplicationContext(), this.exposedContextBeanNames); } return 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).
protected void initServletContext(ServletContext sc) { if (this.exposeForwardAttributes == null && sc.getMajorVersion() == 2 && sc.getMinorVersion() < 5) { this.exposeForwardAttributes = Boolean.TRUE; } } Checks whether we need explictly expose the Servlet 2.4 request attributes by default.
protected boolean isContextRequired() { return false; } An ApplicationContext is not strictly required for InternalResourceView.
protected String prepareForRendering(HttpServletRequest request, HttpServletResponse response) throws Exception { String path = getUrl(); if (this.preventDispatchLoop) { String previousPath = (String) request.getAttribute(DISPATCHED_PATH_ATTRIBUTE); String uri = request.getRequestURI(); if (path.equals(previousPath)) { throw new ServletException("Circular view path [" + path + "]: already dispatched to this " + "view path within the same request [" + uri + "]. Check your ViewResolver setup! " + "(Hint: This may be the result of an unspecified view, due to default view name generation.)"); } if (path.startsWith("/") ? uri.equals(path) : uri.equals(StringUtils.applyRelativePath(uri, path))) { throw new ServletException("Circular view path [" + path + "]: would dispatch back " + "to the current handler URL [" + uri + "] again. Check your ViewResolver setup! " + "(Hint: This may be the result of an unspecified view, due to default view name generation.)"); } request.setAttribute(DISPATCHED_PATH_ATTRIBUTE, path); } return path; } 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.
protected void renderMergedOutputModel(Map model, HttpServletRequest request, HttpServletResponse response) throws Exception { // Determine which request handle to expose to the RequestDispatcher. HttpServletRequest requestToExpose = getRequestToExpose(request); // Expose the model object as request attributes. exposeModelAsRequestAttributes(model, requestToExpose); // Expose helpers as request attributes, if any. exposeHelpers(requestToExpose); // Determine the path for the request dispatcher. String dispatcherPath = prepareForRendering(requestToExpose, response); // Obtain a RequestDispatcher for the target resource (typically a JSP). RequestDispatcher rd = requestToExpose.getRequestDispatcher(dispatcherPath); if (rd == null) { throw new ServletException( "Could not get RequestDispatcher for [" + getUrl() + "]: check that this file exists within your WAR"); } // If already included or response already committed, perform include, else forward. if (useInclude(requestToExpose, response)) { response.setContentType(getContentType()); if (logger.isDebugEnabled()) { logger.debug("Including resource [" + getUrl() + "] in InternalResourceView '" + getBeanName() + "'"); } rd.include(requestToExpose, response); } else { // Note: The forwarded resource is supposed to determine the content type itself. exposeForwardRequestAttributes(requestToExpose); if (logger.isDebugEnabled()) { logger.debug("Forwarding to resource [" + getUrl() + "] in InternalResourceView '" + getBeanName() + "'"); } rd.forward(requestToExpose, response); } } Render the internal resource given the specified model. This includes setting the model as request attributes.
public void setAlwaysInclude(boolean alwaysInclude) { this.alwaysInclude = 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.
public void setExposeContextBeansAsAttributes(boolean exposeContextBeansAsAttributes) { this.exposeContextBeansAsAttributes = 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.
public void setExposeForwardAttributes(boolean exposeForwardAttributes) { this.exposeForwardAttributes = Boolean.valueOf(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.
public void setExposedContextBeanNames(String[] exposedContextBeanNames) { this.exposedContextBeanNames = new HashSet(Arrays.asList(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.
public void setPreventDispatchLoop(boolean preventDispatchLoop) { this.preventDispatchLoop = 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.
protected boolean useInclude(HttpServletRequest request, HttpServletResponse response) { return (this.alwaysInclude \|\| WebUtils.isIncludeRequest(request) \|\| response.isCommitted()); } 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.

Method from org.springframework.web.servlet.view.InternalResourceView Detail:

 protected  void exposeForwardRequestAttributes(HttpServletRequest request) {
		if (this.exposeForwardAttributes != null && this.exposeForwardAttributes.booleanValue()) {
			WebUtils.exposeForwardRequestAttributes(request);
		}
}

HttpServletRequest

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...

 protected  void exposeHelpers(HttpServletRequest request) throws Exception {

}

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

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

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

 protected  void initServletContext(ServletContext sc) {
		if (this.exposeForwardAttributes == null && sc.getMajorVersion() == 2 && sc.getMinorVersion() <  5) {
			this.exposeForwardAttributes = Boolean.TRUE;
		}
}

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

 protected boolean isContextRequired() {
		return false;
}

An ApplicationContext is not strictly required for InternalResourceView.

 protected String prepareForRendering(HttpServletRequest request,
    HttpServletResponse response) throws Exception {
		String path = getUrl();
		if (this.preventDispatchLoop) {
			String previousPath = (String) request.getAttribute(DISPATCHED_PATH_ATTRIBUTE);
			String uri = request.getRequestURI();
			if (path.equals(previousPath)) {
				throw new ServletException("Circular view path [" + path + "]: already dispatched to this " +
						"view path within the same request [" + uri + "]. Check your ViewResolver setup! " +
						"(Hint: This may be the result of an unspecified view, due to default view name generation.)");
			}
			if (path.startsWith("/") ? uri.equals(path) : uri.equals(StringUtils.applyRelativePath(uri, path))) {
				throw new ServletException("Circular view path [" + path + "]: would dispatch back " +
						"to the current handler URL [" + uri + "] again. Check your ViewResolver setup! " +
						"(Hint: This may be the result of an unspecified view, due to default view name generation.)");
			}
			request.setAttribute(DISPATCHED_PATH_ATTRIBUTE, path);
		}
		return path;
}

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.

 protected  void renderMergedOutputModel(Map model,
    HttpServletRequest request,
    HttpServletResponse response) throws Exception {
		// Determine which request handle to expose to the RequestDispatcher.
		HttpServletRequest requestToExpose = getRequestToExpose(request);
		// Expose the model object as request attributes.
		exposeModelAsRequestAttributes(model, requestToExpose);
		// Expose helpers as request attributes, if any.
		exposeHelpers(requestToExpose);
		// Determine the path for the request dispatcher.
		String dispatcherPath = prepareForRendering(requestToExpose, response);
		// Obtain a RequestDispatcher for the target resource (typically a JSP).
		RequestDispatcher rd = requestToExpose.getRequestDispatcher(dispatcherPath);
		if (rd == null) {
			throw new ServletException(
					"Could not get RequestDispatcher for [" + getUrl() + "]: check that this file exists within your WAR");
		}
		// If already included or response already committed, perform include, else forward.
		if (useInclude(requestToExpose, response)) {
			response.setContentType(getContentType());
			if (logger.isDebugEnabled()) {
				logger.debug("Including resource [" + getUrl() + "] in InternalResourceView '" + getBeanName() + "'");
			}
			rd.include(requestToExpose, response);
		}
		else {
			// Note: The forwarded resource is supposed to determine the content type itself.
			exposeForwardRequestAttributes(requestToExpose);
			if (logger.isDebugEnabled()) {
				logger.debug("Forwarding to resource [" + getUrl() + "] in InternalResourceView '" + getBeanName() + "'");
			}
			rd.forward(requestToExpose, response);
		}
}

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

 public  void setAlwaysInclude(boolean alwaysInclude) {
		this.alwaysInclude = alwaysInclude;
}

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

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

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.

 public  void setExposeForwardAttributes(boolean exposeForwardAttributes) {
		this.exposeForwardAttributes = Boolean.valueOf(exposeForwardAttributes);
}

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.

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

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.

 public  void setPreventDispatchLoop(boolean preventDispatchLoop) {
		this.preventDispatchLoop = preventDispatchLoop;
}

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

 protected boolean useInclude(HttpServletRequest request,
    HttpServletResponse response) {
		return (this.alwaysInclude || WebUtils.isIncludeRequest(request) || response.isCommitted());
}

include

forward

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.