Package org.springframework.web.servlet.view

Class UrlBasedViewResolver

java.lang.Object
org.springframework.context.support.ApplicationObjectSupport
org.springframework.web.context.support.WebApplicationObjectSupport
org.springframework.web.servlet.view.AbstractCachingViewResolver
org.springframework.web.servlet.view.UrlBasedViewResolver
All Implemented Interfaces:
Aware, ApplicationContextAware, Ordered, ServletContextAware, ViewResolver
Direct Known Subclasses:
AbstractTemplateViewResolver, InternalResourceViewResolver, ScriptTemplateViewResolver, XsltViewResolver
public class UrlBasedViewResolver extends AbstractCachingViewResolver implements Ordered
Simple implementation of the ViewResolver interface, allowing for direct resolution of symbolic view names to URLs, without explicit mapping definitions. This is useful if your symbolic names match the names of your view resources in a straightforward manner (i.e. the symbolic name is the unique part of the resource's filename), without the need for a dedicated mapping to be defined for each view.

Supports AbstractUrlBasedView subclasses like InternalResourceView and FreeMarkerView. The view class for all views generated by this resolver can be specified via the "viewClass" property.

View names can either be resource URLs themselves, or get augmented by a specified prefix and/or suffix. Exporting an attribute that holds the RequestContext to all views is explicitly supported.

Example: prefix="/WEB-INF/jsp/", suffix=".jsp", viewname="test" → "/WEB-INF/jsp/test.jsp"

As a special feature, redirect URLs can be specified via the "redirect:" prefix. E.g.: "redirect:myAction" will trigger a redirect to the given URL, rather than resolution as standard view name. This is typically used for redirecting to a controller URL after finishing a form workflow.

Furthermore, forward URLs can be specified via the "forward:" prefix. E.g.: "forward:myAction" will trigger a forward to the given URL, rather than resolution as standard view name. This is typically used for controller URLs; it is not supposed to be used for JSP URLs - use logical view names there.

Note: This class does not support localized resolution, i.e. resolving a symbolic view name to different resources depending on the current locale.

Note: When chaining ViewResolvers, a UrlBasedViewResolver will check whether the specified resource actually exists. However, with InternalResourceView, it is not generally possible to determine the existence of the target resource upfront. In such a scenario, a UrlBasedViewResolver will always return a View for any given view name; as a consequence, it should be configured as the last ViewResolver in the chain.

Since:
13.12.2003
Author:
Juergen Hoeller, Rob Harrop, Sam Brannen
See Also:

  • Field Details

    • REDIRECT_URL_PREFIX

      public static final String REDIRECT_URL_PREFIX
      Prefix for special view names that specify a redirect URL (usually to a controller after a form has been submitted and processed). Such view names will not be resolved in the configured default way but rather be treated as special shortcut.
      See Also:

    • FORWARD_URL_PREFIX

      public static final String FORWARD_URL_PREFIX
      Prefix for special view names that specify a forward URL (usually to a controller after a form has been submitted and processed). Such view names will not be resolved in the configured default way but rather be treated as special shortcut.
      See Also:

  • Constructor Details

    • UrlBasedViewResolver

      public UrlBasedViewResolver()

  • Method Details

    • setViewClass

      public void setViewClass(@Nullable Class<?> viewClass)
      Set the view class that should be used to create views.
      Parameters:
      viewClass - a class that is assignable to the required view class (by default: AbstractUrlBasedView)
      See Also:

    • getViewClass

      @Nullable protected Class<?> getViewClass()
      Return the view class to be used to create views.
      See Also:

    • setPrefix

      public void setPrefix(@Nullable String prefix)
      Set the prefix that gets prepended to view names when building a URL.

    • getPrefix

      protected String getPrefix()
      Return the prefix that gets prepended to view names when building a URL.

    • setSuffix

      public void setSuffix(@Nullable String suffix)
      Set the suffix that gets appended to view names when building a URL.

    • getSuffix

      protected String getSuffix()
      Return the suffix that gets appended to view names when building a URL.

    • setContentType

      public void setContentType(@Nullable String contentType)
      Set the content type for all views.

      May be ignored by view classes if the view itself is assumed to set the content type, e.g. in case of JSPs.

    • getContentType

      @Nullable protected String getContentType()
      Return the content type for all views, if any.

    • setRedirectContextRelative

      public void setRedirectContextRelative(boolean redirectContextRelative)
      Set whether to interpret a given redirect URL that starts with a slash ("/") as relative to the current ServletContext, i.e. as relative to the web application root.

      Default is "true": A redirect URL that starts with a slash will be interpreted as relative to the web application root, i.e. the context path will be prepended to the URL.

      Redirect URLs can be specified via the "redirect:" prefix. E.g.: "redirect:myAction"

      See Also:

    • isRedirectContextRelative

      protected boolean isRedirectContextRelative()
      Return whether to interpret a given redirect URL that starts with a slash ("/") as relative to the current ServletContext, i.e. as relative to the web application root.

    • setRedirectHttp10Compatible

      public void setRedirectHttp10Compatible(boolean redirectHttp10Compatible)
      Set whether redirects should stay compatible with HTTP 1.0 clients.

      In the default implementation, this will enforce HTTP status code 302 in any case, i.e. delegate to HttpServletResponse.sendRedirect. Turning this off will send HTTP status code 303, which is the correct code for HTTP 1.1 clients, but not understood by HTTP 1.0 clients.

      Many HTTP 1.1 clients treat 302 just like 303, not making any difference. However, some clients depend on 303 when redirecting after a POST request; turn this flag off in such a scenario.

      Redirect URLs can be specified via the "redirect:" prefix. E.g.: "redirect:myAction"

      See Also:

    • isRedirectHttp10Compatible

      protected boolean isRedirectHttp10Compatible()
      Return whether redirects should stay compatible with HTTP 1.0 clients.

    • setRedirectHosts

      public void setRedirectHosts(@Nullable String... redirectHosts)
      Configure one or more hosts associated with the application. All other hosts will be considered external hosts.

      In effect, this property provides a way turn off encoding on redirect via HttpServletResponse.encodeRedirectURL(java.lang.String) for URLs that have a host and that host is not listed as a known host.

      If not set (the default) all URLs are encoded through the response.

      Parameters:
      redirectHosts - one or more application hosts
      Since:
      4.3

    • getRedirectHosts

      @Nullable public String[] getRedirectHosts()
      Return the configured application hosts for redirect purposes.
      Since:
      4.3

    • setRequestContextAttribute

      public void setRequestContextAttribute(@Nullable String requestContextAttribute)
      Set the name of the RequestContext attribute for all views.
      Parameters:
      requestContextAttribute - name of the RequestContext attribute
      See Also:

    • getRequestContextAttribute

      @Nullable protected String getRequestContextAttribute()
      Return the name of the RequestContext attribute for all views, if any.

    • setAttributes

      public void setAttributes(Properties props)
      Set static attributes from a java.util.Properties object, for all views returned by this resolver.

      This is the most convenient way to set static attributes. Note that static attributes can be overridden by dynamic attributes, if a value with the same name is included in the model.

      Can be populated with a String "value" (parsed via PropertiesEditor) or a "props" element in XML bean definitions.

      See Also:

    • setAttributesMap

      public void setAttributesMap(@Nullable Map<String,?> attributes)
      Set static attributes from a Map, for all views returned by this resolver. This allows to set any kind of attribute values, for example bean references.

      Can be populated with a "map" or "props" element in XML bean definitions.

      Parameters:
      attributes - a Map with name Strings as keys and attribute objects as values
      See Also:

    • getAttributesMap

      public Map<String,Object> getAttributesMap()
      Allow Map access to the static attributes for views returned by this resolver, with the option to add or override specific entries.

      Useful for specifying entries directly, for example via "attributesMap[myKey]". This is particularly useful for adding or overriding entries in child view definitions.

    • setExposePathVariables

      public void setExposePathVariables(@Nullable Boolean exposePathVariables)
      Specify whether views resolved by this resolver should add path variables to the model or not.

      The default setting is to let each View decide (see AbstractView.setExposePathVariables(boolean)). However, you can use this property to override that.

      Parameters:
      exposePathVariables -
      • true - all Views resolved by this resolver will expose path variables
      • false - no Views resolved by this resolver will expose path variables
      • null - individual Views can decide for themselves (this is used by default)
      See Also:

    • getExposePathVariables

      @Nullable protected Boolean getExposePathVariables()
      Return whether views resolved by this resolver should add path variables to the model or not.

    • 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".

      See Also:

    • getExposeContextBeansAsAttributes

      @Nullable protected Boolean getExposeContextBeansAsAttributes()

    • setExposedContextBeanNames

      public void setExposedContextBeanNames(@Nullable 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.
      See Also:

    • getExposedContextBeanNames

      @Nullable protected String[] getExposedContextBeanNames()

    • setViewNames

      public void setViewNames(@Nullable String... viewNames)
      Set the view names (or name patterns) that can be handled by this ViewResolver. View names can contain simple wildcards such that 'my*', '*Report' and '*Repo*' will all match the view name 'myReport'.
      See Also:

    • getViewNames

      @Nullable protected String[] getViewNames()
      Return the view names (or name patterns) that can be handled by this ViewResolver.

    • setOrder

      public void setOrder(int order)
      Specify the order value for this ViewResolver bean.

      The default value is Ordered.LOWEST_PRECEDENCE, meaning non-ordered.

      See Also:

    • getOrder

      public int getOrder()
      Description copied from interface: Ordered
      Get the order value of this object.

      Higher values are interpreted as lower priority. As a consequence, the object with the lowest value has the highest priority (somewhat analogous to Servlet load-on-startup values).

      Same order values will result in arbitrary sort positions for the affected objects.

      Specified by:
      getOrder in interface Ordered
      Returns:
      the order value
      See Also:

    • initApplicationContext

      protected void initApplicationContext()
      Description copied from class: ApplicationObjectSupport
      Subclasses can override this for custom initialization behavior.

      The default implementation is empty. Called by ApplicationObjectSupport.initApplicationContext(org.springframework.context.ApplicationContext).

      Overrides:
      initApplicationContext in class ApplicationObjectSupport
      See Also:

    • getCacheKey

      protected Object getCacheKey(String viewName, Locale locale)
      This implementation returns just the view name, as this ViewResolver doesn't support localized resolution.
      Overrides:
      getCacheKey in class AbstractCachingViewResolver

    • createView

      protected View createView(String viewName, Locale locale) throws Exception
      Overridden to implement check for "redirect:" prefix.

      Not possible in loadView, since overridden loadView versions in subclasses might rely on the superclass always creating instances of the required view class.

      Overrides:
      createView in class AbstractCachingViewResolver
      Parameters:
      viewName - the name of the view to retrieve
      locale - the Locale to retrieve the view for
      Returns:
      the View instance, or null if not found (optional, to allow for ViewResolver chaining)
      Throws:
      Exception - if the view couldn't be resolved
      See Also:

    • canHandle

      protected boolean canHandle(String viewName, Locale locale)
      Indicates whether or not this ViewResolver can handle the supplied view name. If not, createView(String, java.util.Locale) will return null. The default implementation checks against the configured view names.
      Parameters:
      viewName - the name of the view to retrieve
      locale - the Locale to retrieve the view for
      Returns:
      whether this resolver applies to the specified view
      See Also:

    • requiredViewClass

      protected Class<?> requiredViewClass()
      Return the required type of view for this resolver. This implementation returns AbstractUrlBasedView.
      See Also:

    • instantiateView

      protected AbstractUrlBasedView instantiateView()
      Instantiate the specified view class.

      The default implementation uses reflection to instantiate the class.

      Returns:
      a new instance of the view class
      Since:
      5.3
      See Also:

    • loadView

      protected View loadView(String viewName, Locale locale) throws Exception
      Delegates to buildView for creating a new instance of the specified view class. Applies the following Spring lifecycle methods (as supported by the generic Spring bean factory):
      • ApplicationContextAware's setApplicationContext
      • InitializingBean's afterPropertiesSet
      Specified by:
      loadView in class AbstractCachingViewResolver
      Parameters:
      viewName - the name of the view to retrieve
      locale - the Locale to retrieve the view for
      Returns:
      the View instance
      Throws:
      Exception - if the view couldn't be resolved
      See Also:

    • buildView

      protected AbstractUrlBasedView buildView(String viewName) throws Exception
      Creates a new View instance of the specified view class and configures it. Does not perform any lookup for pre-defined View instances.

      Spring lifecycle methods as defined by the bean container do not have to be called here; those will be applied by the loadView method after this method returns.

      Subclasses will typically call super.buildView(viewName) first, before setting further properties themselves. loadView will then apply Spring lifecycle methods at the end of this process.

      Parameters:
      viewName - the name of the view to build
      Returns:
      the View instance
      Throws:
      Exception - if the view couldn't be resolved
      See Also:

    • applyLifecycleMethods

      protected View applyLifecycleMethods(String viewName, AbstractUrlBasedView view)
      Apply the containing ApplicationContext's lifecycle methods to the given View instance, if such a context is available.
      Parameters:
      viewName - the name of the view
      view - the freshly created View instance, pre-configured with AbstractUrlBasedView's properties
      Returns:
      the View instance to use (either the original one or a decorated variant)
      Since:
      5.0
      See Also: