Package org.springframework.web.servlet.view

Class AbstractView

java.lang.Object
org.springframework.context.support.ApplicationObjectSupport
org.springframework.web.context.support.WebApplicationObjectSupport
org.springframework.web.servlet.view.AbstractView
All Implemented Interfaces:
Aware, BeanNameAware, ApplicationContextAware, ServletContextAware, View
Direct Known Subclasses:
AbstractFeedView, AbstractJackson2View, AbstractPdfView, AbstractUrlBasedView, AbstractXlsView, MarshallingView
public abstract class AbstractView extends WebApplicationObjectSupport implements View, BeanNameAware
Abstract base class for View implementations. Subclasses should be JavaBeans, to allow for convenient configuration as Spring-managed bean instances.

Provides support for static attributes, to be made available to the view, with a variety of ways to specify them. Static attributes will be merged with the given dynamic attributes (the model that the controller returned) for each render operation.

Extends WebApplicationObjectSupport, which will be helpful to some views. Subclasses just need to implement the actual rendering.

Author:
Rod Johnson, Juergen Hoeller
See Also:

  • Field Details

    • DEFAULT_CONTENT_TYPE

      public static final String DEFAULT_CONTENT_TYPE
      Default content type. Overridable as bean property.
      See Also:

  • Constructor Details

    • AbstractView

      public AbstractView()

  • Method Details

    • setContentType

      public void setContentType(@Nullable String contentType)
      Set the content type for this view. Default is "text/html;charset=ISO-8859-1".

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

    • getContentType

      @Nullable public String getContentType()
      Return the content type for this view.
      Specified by:
      getContentType in interface View
      Returns:
      the content type String (optionally including a character set), or null if not predetermined

    • setRequestContextAttribute

      public void setRequestContextAttribute(@Nullable String requestContextAttribute)
      Set the name of the RequestContext attribute for this view. Default is none.

    • getRequestContextAttribute

      @Nullable public String getRequestContextAttribute()
      Return the name of the RequestContext attribute, if any.

    • setAttributesCSV

      public void setAttributesCSV(@Nullable String propString) throws IllegalArgumentException
      Set static attributes as a CSV string. Format is: attname0={value1},attname1={value1}

      "Static" attributes are fixed attributes that are specified in the View instance configuration. "Dynamic" attributes, on the other hand, are values passed in as part of the model.

      Throws:
      IllegalArgumentException

    • setAttributes

      public void setAttributes(Properties attributes)
      Set static attributes for this view from a java.util.Properties object.

      "Static" attributes are fixed attributes that are specified in the View instance configuration. "Dynamic" attributes, on the other hand, are values passed in as part of the model.

      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 for this view from a Map. This allows to set any kind of attribute values, for example bean references.

      "Static" attributes are fixed attributes that are specified in the View instance configuration. "Dynamic" attributes, on the other hand, are values passed in as part of the model.

      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

    • getAttributesMap

      public Map<String,Object> getAttributesMap()
      Allow Map access to the static attributes of this view, 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.

    • addStaticAttribute

      public void addStaticAttribute(String name, Object value)
      Add static data to this view, exposed in each view.

      "Static" attributes are fixed attributes that are specified in the View instance configuration. "Dynamic" attributes, on the other hand, are values passed in as part of the model.

      Must be invoked before any calls to render.

      Parameters:
      name - the name of the attribute to expose
      value - the attribute value to expose
      See Also:

    • getStaticAttributes

      public Map<String,Object> getStaticAttributes()
      Return the static attributes for this view. Handy for testing.

      Returns an unmodifiable Map, as this is not intended for manipulating the Map but rather just for checking the contents.

      Returns:
      the static attributes in this view

    • setExposePathVariables

      public void setExposePathVariables(boolean exposePathVariables)
      Specify whether to add path variables to the model or not.

      Path variables are commonly bound to URI template variables through the @PathVariable annotation. They're are effectively URI template variables with type conversion applied to them to derive typed Object values. Such values are frequently needed in views for constructing links to the same and other URLs.

      Path variables added to the model override static attributes (see setAttributes(Properties)) but not attributes already present in the model.

      By default this flag is set to true. Concrete view types can override this.

      Parameters:
      exposePathVariables - true to expose path variables, and false otherwise

    • isExposePathVariables

      public boolean isExposePathVariables()
      Return whether to 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". 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:

    • 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.

    • setBeanName

      public void setBeanName(@Nullable String beanName)
      Set the view's name. Helpful for traceability.

      Framework code must call this when constructing views.

      Specified by:
      setBeanName in interface BeanNameAware
      Parameters:
      beanName - the name of the bean in the factory. Note that this name is the actual bean name used in the factory, which may differ from the originally specified name: in particular for inner bean names, the actual bean name might have been made unique through appending "#..." suffixes. Use the BeanFactoryUtils.originalBeanName(String) method to extract the original bean name (without suffix), if desired.

    • getBeanName

      @Nullable public String getBeanName()
      Return the view's name. Should never be null, if the view was correctly configured.

    • render

      public void render(@Nullable Map<String,?> model, HttpServletRequest request, HttpServletResponse response) throws Exception
      Prepares the view given the specified model, merging it with static attributes and a RequestContext attribute, if necessary. Delegates to renderMergedOutputModel for the actual rendering.
      Specified by:
      render in interface View
      Parameters:
      model - a Map with name Strings as keys and corresponding model objects as values (Map can also be null in case of empty model)
      request - current HTTP request
      response - he HTTP response we are building
      Throws:
      Exception - if rendering failed
      See Also:

    • createMergedOutputModel

      protected Map<String,Object> createMergedOutputModel(@Nullable Map<String,?> model, HttpServletRequest request, HttpServletResponse response)
      Creates a combined output Map (never null) that includes dynamic values and static attributes. Dynamic values take precedence over static attributes.

    • createRequestContext

      protected RequestContext createRequestContext(HttpServletRequest request, HttpServletResponse response, Map<String,Object> model)
      Create a RequestContext to expose under the specified attribute name.

      The default implementation creates a standard RequestContext instance for the given request and model. Can be overridden in subclasses for custom instances.

      Parameters:
      request - current HTTP request
      model - combined output Map (never null), with dynamic values taking precedence over static attributes
      Returns:
      the RequestContext instance
      See Also:

    • prepareResponse

      protected void prepareResponse(HttpServletRequest request, HttpServletResponse response)
      Prepare the given response for rendering.

      The default implementation applies a workaround for an IE bug when sending download content via HTTPS.

      Parameters:
      request - current HTTP request
      response - current HTTP response

    • generatesDownloadContent

      protected boolean generatesDownloadContent()
      Return whether this view generates download content (typically binary content like PDF or Excel files).

      The default implementation returns false. Subclasses are encouraged to return true here if they know that they are generating download content that requires temporary caching on the client side, typically via the response OutputStream.

      See Also:

    • getRequestToExpose

      protected HttpServletRequest getRequestToExpose(HttpServletRequest originalRequest)
      Get the request handle to expose to renderMergedOutputModel(java.util.Map<java.lang.String, java.lang.Object>, jakarta.servlet.http.HttpServletRequest, jakarta.servlet.http.HttpServletResponse), 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:

    • renderMergedOutputModel

      protected abstract void renderMergedOutputModel(Map<String,Object> model, HttpServletRequest request, HttpServletResponse response) throws Exception
      Subclasses must implement this method to actually render the view.

      The first step will be preparing the request: In the JSP case, this would mean setting model objects as request attributes. The second step will be the actual rendering of the view, for example including the JSP via a RequestDispatcher.

      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

    • exposeModelAsRequestAttributes

      protected void exposeModelAsRequestAttributes(Map<String,Object> model, HttpServletRequest request) throws Exception
      Expose the model objects in the given map as request attributes. Names will be taken from the model Map. This method is suitable for all resources reachable by RequestDispatcher.
      Parameters:
      model - a Map of model objects to expose
      request - current HTTP request
      Throws:
      Exception

    • createTemporaryOutputStream

      protected ByteArrayOutputStream createTemporaryOutputStream()
      Create a temporary OutputStream for this view.

      This is typically used as IE workaround, for setting the content length header from the temporary stream before actually writing the content to the HTTP response.

    • writeToResponse

      protected void writeToResponse(HttpServletResponse response, ByteArrayOutputStream baos) throws IOException
      Write the given temporary OutputStream to the HTTP response.
      Parameters:
      response - current HTTP response
      baos - the temporary OutputStream to write
      Throws:
      IOException - if writing/flushing failed

    • setResponseContentType

      protected void setResponseContentType(HttpServletRequest request, HttpServletResponse response)
      Set the content type of the response to the configured content type unless the View.SELECTED_CONTENT_TYPE request attribute is present and set to a concrete media type.

    • toString

      public String toString()
      Overrides:
      toString in class Object

    • formatViewName

      protected String formatViewName()