WebUtils (Spring Framework 4.1.6.RELEASE API)

java.lang.Object
- org.springframework.web.util.WebUtils

```
public abstract class WebUtils
extends Object
```
Miscellaneous utilities for web applications. Used by various framework classes.

Author:

Rod Johnson, Juergen Hoeller, Sebastien Deleuze

Field Summary

Fields
Modifier and Type	Field and Description
`static String`	`CONTENT_TYPE_CHARSET_PREFIX` Prefix of the charset clause in a content type String: ";charset="
`static String`	`DEFAULT_CHARACTER_ENCODING` Default character encoding to use when `request.getCharacterEncoding` returns `null`, according to the Servlet spec.
`static String`	`DEFAULT_WEB_APP_ROOT_KEY` Default web app root key: "webapp.root"
`static String`	`ERROR_EXCEPTION_ATTRIBUTE`
`static String`	`ERROR_EXCEPTION_TYPE_ATTRIBUTE`
`static String`	`ERROR_MESSAGE_ATTRIBUTE`
`static String`	`ERROR_REQUEST_URI_ATTRIBUTE`
`static String`	`ERROR_SERVLET_NAME_ATTRIBUTE`
`static String`	`ERROR_STATUS_CODE_ATTRIBUTE` Standard Servlet 2.3+ spec request attributes for error pages.
`static String`	`FORWARD_CONTEXT_PATH_ATTRIBUTE`
`static String`	`FORWARD_PATH_INFO_ATTRIBUTE`
`static String`	`FORWARD_QUERY_STRING_ATTRIBUTE`
`static String`	`FORWARD_REQUEST_URI_ATTRIBUTE` Standard Servlet 2.4+ spec request attributes for forward URI and paths.
`static String`	`FORWARD_SERVLET_PATH_ATTRIBUTE`
`static String`	`HTML_ESCAPE_CONTEXT_PARAM` HTML escape parameter at the servlet context level (i.e.
`static String`	`INCLUDE_CONTEXT_PATH_ATTRIBUTE`
`static String`	`INCLUDE_PATH_INFO_ATTRIBUTE`
`static String`	`INCLUDE_QUERY_STRING_ATTRIBUTE`
`static String`	`INCLUDE_REQUEST_URI_ATTRIBUTE` Standard Servlet 2.3+ spec request attributes for include URI and paths.
`static String`	`INCLUDE_SERVLET_PATH_ATTRIBUTE`
`static String`	`RESPONSE_ENCODED_HTML_ESCAPE_CONTEXT_PARAM` Use of response encoding for HTML escaping parameter at the servlet context level (i.e.
`static String`	`SESSION_MUTEX_ATTRIBUTE` Key for the mutex session attribute
`static String[]`	`SUBMIT_IMAGE_SUFFIXES` Name suffixes in case of image buttons
`static String`	`TEMP_DIR_CONTEXT_ATTRIBUTE` Standard Servlet spec context attribute that specifies a temporary directory for the current web application, of type `java.io.File`.
`static String`	`WEB_APP_ROOT_KEY_PARAM` Web app root key parameter at the servlet context level (i.e.

Constructor Summary

Constructors
Constructor and Description

WebUtils()

Constructors
Constructor and Description
`WebUtils()`

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method and Description
`static void`	`clearErrorRequestAttributes(HttpServletRequest request)` Clear the Servlet spec's error attributes as `HttpServletRequest` attributes under the keys defined in the Servlet 2.3 specification: `javax.servlet.error.status_code`, `javax.servlet.error.exception_type`, `javax.servlet.error.message`, `javax.servlet.error.exception`, `javax.servlet.error.request_uri`, `javax.servlet.error.servlet_name`.
`static void`	`exposeErrorRequestAttributes(HttpServletRequest request, Throwable ex, String servletName)` Expose the Servlet spec's error attributes as `HttpServletRequest` attributes under the keys defined in the Servlet 2.3 specification, for error pages that are rendered directly rather than through the Servlet container's error page resolution: `javax.servlet.error.status_code`, `javax.servlet.error.exception_type`, `javax.servlet.error.message`, `javax.servlet.error.exception`, `javax.servlet.error.request_uri`, `javax.servlet.error.servlet_name`.
`static void`	`exposeRequestAttributes(ServletRequest request, Map<String,?> attributes)` Expose the given Map as request attributes, using the keys as attribute names and the values as corresponding attribute values.
`static String`	`extractFilenameFromUrlPath(String urlPath)` Extract the URL filename from the given request URL path.
`static String`	`extractFullFilenameFromUrlPath(String urlPath)` Extract the full URL filename (including file extension) from the given request URL path.
`static String`	`findParameterValue(Map<String,?> parameters, String name)` Obtain a named parameter from the given request parameters.
`static String`	`findParameterValue(ServletRequest request, String name)` Obtain a named parameter from the given request parameters.
`static Cookie`	`getCookie(HttpServletRequest request, String name)` Retrieve the first cookie with the given name.
`static Boolean`	`getDefaultHtmlEscape(ServletContext servletContext)` Return whether default HTML escaping is enabled for the web application, i.e.
`static <T> T`	`getNativeRequest(ServletRequest request, Class<T> requiredType)` Return an appropriate request object of the specified type, if available, unwrapping the given request as far as necessary.
`static <T> T`	`getNativeResponse(ServletResponse response, Class<T> requiredType)` Return an appropriate response object of the specified type, if available, unwrapping the given response as far as necessary.
`static Object`	`getOrCreateSessionAttribute(HttpSession session, String name, Class<?> clazz)` Get the specified session attribute, creating and setting a new attribute if no existing found.
`static Map<String,Object>`	`getParametersStartingWith(ServletRequest request, String prefix)` Return a map containing all parameters with the given prefix.
`static String`	`getRealPath(ServletContext servletContext, String path)` Return the real path of the given path within the web application, as provided by the servlet container.
`static Object`	`getRequiredSessionAttribute(HttpServletRequest request, String name)` Check the given request for a session attribute of the given name.
`static Boolean`	`getResponseEncodedHtmlEscape(ServletContext servletContext)` Return whether response encoding should be used when HTML escaping characters, thus only escaping XML markup significant characters with UTF-* encodings.
`static Object`	`getSessionAttribute(HttpServletRequest request, String name)` Check the given request for a session attribute of the given name.
`static String`	`getSessionId(HttpServletRequest request)` Determine the session id of the given request, if any.
`static Object`	`getSessionMutex(HttpSession session)` Return the best available mutex for the given session: that is, an object to synchronize on for the given session.
`static int`	`getTargetPage(ServletRequest request, String paramPrefix, int currentPage)` Return the target page specified in the request.
`static File`	`getTempDir(ServletContext servletContext)` Return the temporary directory for the current web application, as provided by the servlet container.
`static boolean`	`hasSubmitParameter(ServletRequest request, String name)` Check if a specific input type="submit" parameter was sent in the request, either via a button (directly with name) or via an image (name + ".x" or name + ".y").
`static boolean`	`isDefaultHtmlEscape(ServletContext servletContext)` Deprecated. as of Spring 4.1, in favor of `getDefaultHtmlEscape(javax.servlet.ServletContext)`
`static boolean`	`isIncludeRequest(ServletRequest request)` Determine whether the given request is an include request, that is, not a top-level HTTP request coming in from the outside.
`static boolean`	`isValidOrigin(HttpRequest request, Collection<String> allowedOrigins)` Check the given request origin against a list of allowed origins.
`static MultiValueMap<String,String>`	`parseMatrixVariables(String matrixVariables)` Parse the given string with matrix variables.
`static void`	`removeWebAppRootSystemProperty(ServletContext servletContext)` Remove the system property that points to the web app root directory.
`static void`	`setSessionAttribute(HttpServletRequest request, String name, Object value)` Set the session attribute with the given name to the given value.
`static void`	`setWebAppRootSystemProperty(ServletContext servletContext)` Set a system property to the web application root directory.

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

- Field Detail
  - INCLUDE_REQUEST_URI_ATTRIBUTE
```
public static final String INCLUDE_REQUEST_URI_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attributes for include URI and paths.
    If included via a RequestDispatcher, the current resource will see the originating request. Its own URI and paths are exposed as request attributes.
    
    See Also:
    
    Constant Field Values
  - INCLUDE_CONTEXT_PATH_ATTRIBUTE
```
public static final String INCLUDE_CONTEXT_PATH_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - INCLUDE_SERVLET_PATH_ATTRIBUTE
```
public static final String INCLUDE_SERVLET_PATH_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - INCLUDE_PATH_INFO_ATTRIBUTE
```
public static final String INCLUDE_PATH_INFO_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - INCLUDE_QUERY_STRING_ATTRIBUTE
```
public static final String INCLUDE_QUERY_STRING_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - FORWARD_REQUEST_URI_ATTRIBUTE
```
public static final String FORWARD_REQUEST_URI_ATTRIBUTE
```
    Standard Servlet 2.4+ spec request attributes for forward URI and paths.
    If forwarded to via a RequestDispatcher, the current resource will see its own URI and paths. The originating URI and paths are exposed as request attributes.
    
    See Also:
    
    Constant Field Values
  - FORWARD_CONTEXT_PATH_ATTRIBUTE
```
public static final String FORWARD_CONTEXT_PATH_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - FORWARD_SERVLET_PATH_ATTRIBUTE
```
public static final String FORWARD_SERVLET_PATH_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - FORWARD_PATH_INFO_ATTRIBUTE
```
public static final String FORWARD_PATH_INFO_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - FORWARD_QUERY_STRING_ATTRIBUTE
```
public static final String FORWARD_QUERY_STRING_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - ERROR_STATUS_CODE_ATTRIBUTE
```
public static final String ERROR_STATUS_CODE_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attributes for error pages.
    To be exposed to JSPs that are marked as error pages, when forwarding to them directly rather than through the servlet container's error page resolution mechanism.
    
    See Also:
    
    Constant Field Values
  - ERROR_EXCEPTION_TYPE_ATTRIBUTE
```
public static final String ERROR_EXCEPTION_TYPE_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - ERROR_MESSAGE_ATTRIBUTE
```
public static final String ERROR_MESSAGE_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - ERROR_EXCEPTION_ATTRIBUTE
```
public static final String ERROR_EXCEPTION_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - ERROR_REQUEST_URI_ATTRIBUTE
```
public static final String ERROR_REQUEST_URI_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - ERROR_SERVLET_NAME_ATTRIBUTE
```
public static final String ERROR_SERVLET_NAME_ATTRIBUTE
```
    See Also:
    
    Constant Field Values
  - CONTENT_TYPE_CHARSET_PREFIX
```
public static final String CONTENT_TYPE_CHARSET_PREFIX
```
    Prefix of the charset clause in a content type String: ";charset="
    
    See Also:
    
    Constant Field Values
  - DEFAULT_CHARACTER_ENCODING
```
public static final String DEFAULT_CHARACTER_ENCODING
```
    Default character encoding to use when request.getCharacterEncoding returns null, according to the Servlet spec.
    
    See Also:
    
    ServletRequest.getCharacterEncoding(), Constant Field Values
  - TEMP_DIR_CONTEXT_ATTRIBUTE
```
public static final String TEMP_DIR_CONTEXT_ATTRIBUTE
```
    Standard Servlet spec context attribute that specifies a temporary directory for the current web application, of type java.io.File.
    
    See Also:
    
    Constant Field Values
  - HTML_ESCAPE_CONTEXT_PARAM
```
public static final String HTML_ESCAPE_CONTEXT_PARAM
```
    HTML escape parameter at the servlet context level (i.e. a context-param in web.xml): "defaultHtmlEscape".
    
    See Also:
    
    Constant Field Values
  - RESPONSE_ENCODED_HTML_ESCAPE_CONTEXT_PARAM
```
public static final String RESPONSE_ENCODED_HTML_ESCAPE_CONTEXT_PARAM
```
    Use of response encoding for HTML escaping parameter at the servlet context level (i.e. a context-param in web.xml): "responseEncodedHtmlEscape".
    
    Since:
    
    4.1.2
    
    See Also:
    
    Constant Field Values
  - WEB_APP_ROOT_KEY_PARAM
```
public static final String WEB_APP_ROOT_KEY_PARAM
```
    Web app root key parameter at the servlet context level (i.e. a context-param in web.xml): "webAppRootKey".
    
    See Also:
    
    Constant Field Values
  - DEFAULT_WEB_APP_ROOT_KEY
```
public static final String DEFAULT_WEB_APP_ROOT_KEY
```
    Default web app root key: "webapp.root"
    
    See Also:
    
    Constant Field Values
  - SUBMIT_IMAGE_SUFFIXES
```
public static final String[] SUBMIT_IMAGE_SUFFIXES
```
    Name suffixes in case of image buttons
  - SESSION_MUTEX_ATTRIBUTE
```
public static final String SESSION_MUTEX_ATTRIBUTE
```
    Key for the mutex session attribute
- Constructor Detail
  - WebUtils
```
public WebUtils()
```
- Method Detail
  - setWebAppRootSystemProperty
```
public static void setWebAppRootSystemProperty(ServletContext servletContext)
                                        throws IllegalStateException
```
    Set a system property to the web application root directory. The key of the system property can be defined with the "webAppRootKey" context-param in web.xml. Default is "webapp.root".
    Can be used for tools that support substition with System.getProperty values, like log4j's "${key}" syntax within log file locations.
    
    Parameters:
    
    servletContext - the servlet context of the web application
    
    Throws:
    
    IllegalStateException - if the system property is already set, or if the WAR file is not expanded
    
    See Also:
    
    WEB_APP_ROOT_KEY_PARAM, DEFAULT_WEB_APP_ROOT_KEY, WebAppRootListener, Log4jWebConfigurer
  - removeWebAppRootSystemProperty
```
public static void removeWebAppRootSystemProperty(ServletContext servletContext)
```
    Remove the system property that points to the web app root directory. To be called on shutdown of the web application.
    
    Parameters:
    
    servletContext - the servlet context of the web application
    
    See Also:
    
    setWebAppRootSystemProperty(javax.servlet.ServletContext)
  - isDefaultHtmlEscape
```
@Deprecated
public static boolean isDefaultHtmlEscape(ServletContext servletContext)
```
    Deprecated. as of Spring 4.1, in favor of getDefaultHtmlEscape(javax.servlet.ServletContext)
    
    Return whether default HTML escaping is enabled for the web application, i.e. the value of the "defaultHtmlEscape" context-param in web.xml (if any). Falls back to false in case of no explicit default given.
    
    Parameters:
    
    servletContext - the servlet context of the web application
    
    Returns:
    
    whether default HTML escaping is enabled (default is false)
  - getDefaultHtmlEscape
```
public static Boolean getDefaultHtmlEscape(ServletContext servletContext)
```
    Return whether default HTML escaping is enabled for the web application, i.e. the value of the "defaultHtmlEscape" context-param in web.xml (if any).
    This method differentiates between no param specified at all and an actual boolean value specified, allowing to have a context-specific default in case of no setting at the global level.
    
    Parameters:
    
    servletContext - the servlet context of the web application
    
    Returns:
    
    whether default HTML escaping is enabled (null = no explicit default)
  - getResponseEncodedHtmlEscape
```
public static Boolean getResponseEncodedHtmlEscape(ServletContext servletContext)
```
    Return whether response encoding should be used when HTML escaping characters, thus only escaping XML markup significant characters with UTF-* encodings. This option is enabled for the web application with a ServletContext param, i.e. the value of the "responseEncodedHtmlEscape" context-param in web.xml (if any).
    This method differentiates between no param specified at all and an actual boolean value specified, allowing to have a context-specific default in case of no setting at the global level.
    
    Parameters:
    
    servletContext - the servlet context of the web application
    
    Returns:
    
    whether response encoding is used for HTML escaping (null = no explicit default)
    
    Since:
    
    4.1.2
  - getTempDir
```
public static File getTempDir(ServletContext servletContext)
```
    Return the temporary directory for the current web application, as provided by the servlet container.
    
    Parameters:
    
    servletContext - the servlet context of the web application
    
    Returns:
    
    the File representing the temporary directory
  - getRealPath
```
public static String getRealPath(ServletContext servletContext,
                                 String path)
                          throws FileNotFoundException
```
    Return the real path of the given path within the web application, as provided by the servlet container.
    Prepends a slash if the path does not already start with a slash, and throws a FileNotFoundException if the path cannot be resolved to a resource (in contrast to ServletContext's getRealPath, which returns null).
    
    Parameters:
    
    servletContext - the servlet context of the web application
    
    path - the path within the web application
    
    Returns:
    
    the corresponding real path
    
    Throws:
    
    FileNotFoundException - if the path cannot be resolved to a resource
    
    See Also:
    
    ServletContext.getRealPath(java.lang.String)
  - getSessionId
```
public static String getSessionId(HttpServletRequest request)
```
    Determine the session id of the given request, if any.
    
    Parameters:
    
    request - current HTTP request
    
    Returns:
    
    the session id, or null if none
  - getSessionAttribute
```
public static Object getSessionAttribute(HttpServletRequest request,
                                         String name)
```
    Check the given request for a session attribute of the given name. Returns null if there is no session or if the session has no such attribute. Does not create a new session if none has existed before!
    
    Parameters:
    
    request - current HTTP request
    
    name - the name of the session attribute
    
    Returns:
    
    the value of the session attribute, or null if not found
  - getRequiredSessionAttribute
```
public static Object getRequiredSessionAttribute(HttpServletRequest request,
                                                 String name)
                                          throws IllegalStateException
```
    Check the given request for a session attribute of the given name. Throws an exception if there is no session or if the session has no such attribute. Does not create a new session if none has existed before!
    
    Parameters:
    
    request - current HTTP request
    
    name - the name of the session attribute
    
    Returns:
    
    the value of the session attribute, or null if not found
    
    Throws:
    
    IllegalStateException - if the session attribute could not be found
  - setSessionAttribute
```
public static void setSessionAttribute(HttpServletRequest request,
                                       String name,
                                       Object value)
```
    Set the session attribute with the given name to the given value. Removes the session attribute if value is null, if a session existed at all. Does not create a new session if not necessary!
    
    Parameters:
    
    request - current HTTP request
    
    name - the name of the session attribute
    
    value - the value of the session attribute
  - getOrCreateSessionAttribute
```
public static Object getOrCreateSessionAttribute(HttpSession session,
                                                 String name,
                                                 Class<?> clazz)
                                          throws IllegalArgumentException
```
    Get the specified session attribute, creating and setting a new attribute if no existing found. The given class needs to have a public no-arg constructor. Useful for on-demand state objects in a web tier, like shopping carts.
    
    Parameters:
    
    session - current HTTP session
    
    name - the name of the session attribute
    
    clazz - the class to instantiate for a new attribute
    
    Returns:
    
    the value of the session attribute, newly created if not found
    
    Throws:
    
    IllegalArgumentException - if the session attribute could not be instantiated
  - getSessionMutex
```
public static Object getSessionMutex(HttpSession session)
```
    Return the best available mutex for the given session: that is, an object to synchronize on for the given session.
    Returns the session mutex attribute if available; usually, this means that the HttpSessionMutexListener needs to be defined in web.xml. Falls back to the HttpSession itself if no mutex attribute found.
    The session mutex is guaranteed to be the same object during the entire lifetime of the session, available under the key defined by the SESSION_MUTEX_ATTRIBUTE constant. It serves as a safe reference to synchronize on for locking on the current session.
    In many cases, the HttpSession reference itself is a safe mutex as well, since it will always be the same object reference for the same active logical session. However, this is not guaranteed across different servlet containers; the only 100% safe way is a session mutex.
    
    Parameters:
    
    session - the HttpSession to find a mutex for
    
    Returns:
    
    the mutex object (never null)
    
    See Also:
    
    SESSION_MUTEX_ATTRIBUTE, HttpSessionMutexListener
  - getNativeRequest
```
public static <T> T getNativeRequest(ServletRequest request,
                                     Class<T> requiredType)
```
    Return an appropriate request object of the specified type, if available, unwrapping the given request as far as necessary.
    
    Parameters:
    
    request - the servlet request to introspect
    
    requiredType - the desired type of request object
    
    Returns:
    
    the matching request object, or null if none of that type is available
  - getNativeResponse
```
public static <T> T getNativeResponse(ServletResponse response,
                                      Class<T> requiredType)
```
    Return an appropriate response object of the specified type, if available, unwrapping the given response as far as necessary.
    
    Parameters:
    
    response - the servlet response to introspect
    
    requiredType - the desired type of response object
    
    Returns:
    
    the matching response object, or null if none of that type is available
  - isIncludeRequest
```
public static boolean isIncludeRequest(ServletRequest request)
```
    Determine whether the given request is an include request, that is, not a top-level HTTP request coming in from the outside.
    Checks the presence of the "javax.servlet.include.request_uri" request attribute. Could check any request attribute that is only present in an include request.
    
    Parameters:
    
    request - current servlet request
    
    Returns:
    
    whether the given request is an include request
  - exposeErrorRequestAttributes
```
public static void exposeErrorRequestAttributes(HttpServletRequest request,
                                                Throwable ex,
                                                String servletName)
```
    Expose the Servlet spec's error attributes as HttpServletRequest attributes under the keys defined in the Servlet 2.3 specification, for error pages that are rendered directly rather than through the Servlet container's error page resolution: javax.servlet.error.status_code, javax.servlet.error.exception_type, javax.servlet.error.message, javax.servlet.error.exception, javax.servlet.error.request_uri, javax.servlet.error.servlet_name.
    Does not override values if already present, to respect attribute values that have been exposed explicitly before.
    Exposes status code 200 by default. Set the "javax.servlet.error.status_code" attribute explicitly (before or after) in order to expose a different status code.
    
    Parameters:
    
    request - current servlet request
    
    ex - the exception encountered
    
    servletName - the name of the offending servlet
  - clearErrorRequestAttributes
```
public static void clearErrorRequestAttributes(HttpServletRequest request)
```
    Clear the Servlet spec's error attributes as HttpServletRequest attributes under the keys defined in the Servlet 2.3 specification: javax.servlet.error.status_code, javax.servlet.error.exception_type, javax.servlet.error.message, javax.servlet.error.exception, javax.servlet.error.request_uri, javax.servlet.error.servlet_name.
    
    Parameters:
    
    request - current servlet request
  - exposeRequestAttributes
```
public static void exposeRequestAttributes(ServletRequest request,
                                           Map<String,?> attributes)
```
    Expose the given Map as request attributes, using the keys as attribute names and the values as corresponding attribute values. Keys need to be Strings.
    
    Parameters:
    
    request - current HTTP request
    
    attributes - the attributes Map
  - getCookie
```
public static Cookie getCookie(HttpServletRequest request,
                               String name)
```
    Retrieve the first cookie with the given name. Note that multiple cookies can have the same name but different paths or domains.
    
    Parameters:
    
    request - current servlet request
    
    name - cookie name
    
    Returns:
    
    the first cookie with the given name, or null if none is found
  - hasSubmitParameter
```
public static boolean hasSubmitParameter(ServletRequest request,
                                         String name)
```
    Check if a specific input type="submit" parameter was sent in the request, either via a button (directly with name) or via an image (name + ".x" or name + ".y").
    
    Parameters:
    
    request - current HTTP request
    
    name - name of the parameter
    
    Returns:
    
    if the parameter was sent
    
    See Also:
    
    SUBMIT_IMAGE_SUFFIXES
  - findParameterValue
```
public static String findParameterValue(ServletRequest request,
                                        String name)
```
    Obtain a named parameter from the given request parameters.
    See findParameterValue(java.util.Map, String) for a description of the lookup algorithm.
    
    Parameters:
    
    request - current HTTP request
    
    name - the logical name of the request parameter
    
    Returns:
    
    the value of the parameter, or null if the parameter does not exist in given request
  - findParameterValue
```
public static String findParameterValue(Map<String,?> parameters,
                                        String name)
```
    Obtain a named parameter from the given request parameters.
    This method will try to obtain a parameter value using the following algorithm:
    1. Try to get the parameter value using just the given logical name. This handles parameters of the form logicalName = value. For normal parameters, e.g. submitted using a hidden HTML form field, this will return the requested value.
    2. Try to obtain the parameter value from the parameter name, where the parameter name in the request is of the form logicalName_value = xyz with "_" being the configured delimiter. This deals with parameter values submitted using an HTML form submit button.
    3. If the value obtained in the previous step has a ".x" or ".y" suffix, remove that. This handles cases where the value was submitted using an HTML form image button. In this case the parameter in the request would actually be of the form logicalName_value.x = 123.
    Parameters:
    
    parameters - the available parameter map
    
    name - the logical name of the request parameter
    
    Returns:
    
    the value of the parameter, or null if the parameter does not exist in given request
  - getParametersStartingWith
```
public static Map<String,Object> getParametersStartingWith(ServletRequest request,
                                                           String prefix)
```
    Return a map containing all parameters with the given prefix. Maps single values to String and multiple values to String array.
    For example, with a prefix of "spring_", "spring_param1" and "spring_param2" result in a Map with "param1" and "param2" as keys.
    
    Parameters:
    
    request - HTTP request in which to look for parameters
    
    prefix - the beginning of parameter names (if this is null or the empty string, all parameters will match)
    
    Returns:
    
    map containing request parameters without the prefix, containing either a String or a String array as values
    
    See Also:
    
    ServletRequest.getParameterNames(), ServletRequest.getParameterValues(java.lang.String), ServletRequest.getParameterMap()
  - getTargetPage
```
public static int getTargetPage(ServletRequest request,
                                String paramPrefix,
                                int currentPage)
```
    Return the target page specified in the request.
    
    Parameters:
    
    request - current servlet request
    
    paramPrefix - the parameter prefix to check for (e.g. "_target" for parameters like "_target1" or "_target2")
    
    currentPage - the current page, to be returned as fallback if no target page specified
    
    Returns:
    
    the page specified in the request, or current page if not found
  - extractFilenameFromUrlPath
```
public static String extractFilenameFromUrlPath(String urlPath)
```
    Extract the URL filename from the given request URL path. Correctly resolves nested paths such as "/products/view.html" as well.
    
    Parameters:
    
    urlPath - the request URL path (e.g. "/index.html")
    
    Returns:
    
    the extracted URI filename (e.g. "index")
  - extractFullFilenameFromUrlPath
```
public static String extractFullFilenameFromUrlPath(String urlPath)
```
    Extract the full URL filename (including file extension) from the given request URL path. Correctly resolves nested paths such as "/products/view.html" as well.
    
    Parameters:
    
    urlPath - the request URL path (e.g. "/products/index.html")
    
    Returns:
    
    the extracted URI filename (e.g. "index.html")
  - parseMatrixVariables
```
public static MultiValueMap<String,String> parseMatrixVariables(String matrixVariables)
```
    Parse the given string with matrix variables. An example string would look like this "q1=a;q1=b;q2=a,b,c". The resulting map would contain keys "q1" and "q2" with values ["a","b"] and ["a","b","c"] respectively.
    
    Parameters:
    
    matrixVariables - the unparsed matrix variables string
    
    Returns:
    
    a map with matrix variable names and values, never null
    
    Since:
    
    3.2
  - isValidOrigin
```
public static boolean isValidOrigin(HttpRequest request,
                                    Collection<String> allowedOrigins)
```
    Check the given request origin against a list of allowed origins. A list containing "*" means that all origins are allowed. An empty list means only same origin is allowed.
    
    Returns:
    
    true if the request origin is valid, false otherwise
    
    Since:
    
    4.1.5
    
    See Also:
    
    RFC 6454: The Web Origin Concept

Class WebUtils

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

INCLUDE_REQUEST_URI_ATTRIBUTE

INCLUDE_CONTEXT_PATH_ATTRIBUTE

INCLUDE_SERVLET_PATH_ATTRIBUTE

INCLUDE_PATH_INFO_ATTRIBUTE

INCLUDE_QUERY_STRING_ATTRIBUTE

FORWARD_REQUEST_URI_ATTRIBUTE

FORWARD_CONTEXT_PATH_ATTRIBUTE

FORWARD_SERVLET_PATH_ATTRIBUTE

FORWARD_PATH_INFO_ATTRIBUTE

FORWARD_QUERY_STRING_ATTRIBUTE

ERROR_STATUS_CODE_ATTRIBUTE

ERROR_EXCEPTION_TYPE_ATTRIBUTE

ERROR_MESSAGE_ATTRIBUTE

ERROR_EXCEPTION_ATTRIBUTE

ERROR_REQUEST_URI_ATTRIBUTE

ERROR_SERVLET_NAME_ATTRIBUTE

CONTENT_TYPE_CHARSET_PREFIX

DEFAULT_CHARACTER_ENCODING

TEMP_DIR_CONTEXT_ATTRIBUTE

HTML_ESCAPE_CONTEXT_PARAM

RESPONSE_ENCODED_HTML_ESCAPE_CONTEXT_PARAM

WEB_APP_ROOT_KEY_PARAM

DEFAULT_WEB_APP_ROOT_KEY

SUBMIT_IMAGE_SUFFIXES

SESSION_MUTEX_ATTRIBUTE

Constructor Detail

WebUtils

Method Detail

setWebAppRootSystemProperty

removeWebAppRootSystemProperty

isDefaultHtmlEscape

getDefaultHtmlEscape

getResponseEncodedHtmlEscape

getTempDir

getRealPath

getSessionId

getSessionAttribute

getRequiredSessionAttribute

setSessionAttribute

getOrCreateSessionAttribute

getSessionMutex

getNativeRequest

getNativeResponse

isIncludeRequest

exposeErrorRequestAttributes

clearErrorRequestAttributes

exposeRequestAttributes

getCookie

hasSubmitParameter

findParameterValue

findParameterValue

getParametersStartingWith

getTargetPage

extractFilenameFromUrlPath

extractFullFilenameFromUrlPath

parseMatrixVariables

isValidOrigin