WebUtils (Spring Framework 5.1.0.RELEASE API)

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

```
public abstract class WebUtils
extends java.lang.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 java.lang.String`	`CONTENT_TYPE_CHARSET_PREFIX` Prefix of the charset clause in a content type String: ";charset=".
`static java.lang.String`	`DEFAULT_CHARACTER_ENCODING` Default character encoding to use when `request.getCharacterEncoding` returns `null`, according to the Servlet spec.
`static java.lang.String`	`DEFAULT_WEB_APP_ROOT_KEY` Default web app root key: "webapp.root".
`static java.lang.String`	`ERROR_EXCEPTION_ATTRIBUTE` Standard Servlet 2.3+ spec request attribute for error page exception.
`static java.lang.String`	`ERROR_EXCEPTION_TYPE_ATTRIBUTE` Standard Servlet 2.3+ spec request attribute for error page exception type.
`static java.lang.String`	`ERROR_MESSAGE_ATTRIBUTE` Standard Servlet 2.3+ spec request attribute for error page message.
`static java.lang.String`	`ERROR_REQUEST_URI_ATTRIBUTE` Standard Servlet 2.3+ spec request attribute for error page request URI.
`static java.lang.String`	`ERROR_SERVLET_NAME_ATTRIBUTE` Standard Servlet 2.3+ spec request attribute for error page servlet name.
`static java.lang.String`	`ERROR_STATUS_CODE_ATTRIBUTE` Standard Servlet 2.3+ spec request attribute for error page status code.
`static java.lang.String`	`FORWARD_CONTEXT_PATH_ATTRIBUTE` Standard Servlet 2.4+ spec request attribute for forward context path.
`static java.lang.String`	`FORWARD_PATH_INFO_ATTRIBUTE` Standard Servlet 2.4+ spec request attribute for forward path info.
`static java.lang.String`	`FORWARD_QUERY_STRING_ATTRIBUTE` Standard Servlet 2.4+ spec request attribute for forward query string.
`static java.lang.String`	`FORWARD_REQUEST_URI_ATTRIBUTE` Standard Servlet 2.4+ spec request attribute for forward request URI.
`static java.lang.String`	`FORWARD_SERVLET_PATH_ATTRIBUTE` Standard Servlet 2.4+ spec request attribute for forward servlet path.
`static java.lang.String`	`HTML_ESCAPE_CONTEXT_PARAM` HTML escape parameter at the servlet context level (i.e.
`static java.lang.String`	`INCLUDE_CONTEXT_PATH_ATTRIBUTE` Standard Servlet 2.3+ spec request attribute for include context path.
`static java.lang.String`	`INCLUDE_PATH_INFO_ATTRIBUTE` Standard Servlet 2.3+ spec request attribute for include path info.
`static java.lang.String`	`INCLUDE_QUERY_STRING_ATTRIBUTE` Standard Servlet 2.3+ spec request attribute for include query string.
`static java.lang.String`	`INCLUDE_REQUEST_URI_ATTRIBUTE` Standard Servlet 2.3+ spec request attribute for include request URI.
`static java.lang.String`	`INCLUDE_SERVLET_PATH_ATTRIBUTE` Standard Servlet 2.3+ spec request attribute for include servlet path.
`static java.lang.String`	`RESPONSE_ENCODED_HTML_ESCAPE_CONTEXT_PARAM` Use of response encoding for HTML escaping parameter at the servlet context level (i.e.
`static java.lang.String`	`SESSION_MUTEX_ATTRIBUTE` Key for the mutex session attribute.
`static java.lang.String[]`	`SUBMIT_IMAGE_SUFFIXES` Name suffixes in case of image buttons.
`static java.lang.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 java.lang.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
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, java.lang.Throwable ex, java.lang.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 java.lang.String`	`findParameterValue(java.util.Map<java.lang.String,?> parameters, java.lang.String name)` Obtain a named parameter from the given request parameters.
`static java.lang.String`	`findParameterValue(ServletRequest request, java.lang.String name)` Obtain a named parameter from the given request parameters.
`static Cookie`	`getCookie(HttpServletRequest request, java.lang.String name)` Retrieve the first cookie with the given name.
`static java.lang.Boolean`	`getDefaultHtmlEscape(ServletContext servletContext)` Return whether default HTML escaping is enabled for the web application, i.e.
`static <T> T`	`getNativeRequest(ServletRequest request, java.lang.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, java.lang.Class<T> requiredType)` Return an appropriate response object of the specified type, if available, unwrapping the given response as far as necessary.
`static java.util.Map<java.lang.String,java.lang.Object>`	`getParametersStartingWith(ServletRequest request, java.lang.String prefix)` Return a map containing all parameters with the given prefix.
`static java.lang.String`	`getRealPath(ServletContext servletContext, java.lang.String path)` Return the real path of the given path within the web application, as provided by the servlet container.
`static java.lang.Object`	`getRequiredSessionAttribute(HttpServletRequest request, java.lang.String name)` Check the given request for a session attribute of the given name.
`static java.lang.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 java.lang.Object`	`getSessionAttribute(HttpServletRequest request, java.lang.String name)` Check the given request for a session attribute of the given name.
`static java.lang.String`	`getSessionId(HttpServletRequest request)` Determine the session id of the given request, if any.
`static java.lang.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 java.io.File`	`getTempDir(ServletContext servletContext)` Return the temporary directory for the current web application, as provided by the servlet container.
`static boolean`	`hasSubmitParameter(ServletRequest request, java.lang.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`	`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`	`isSameOrigin(HttpRequest request)` Check if the request is a same-origin one, based on `Origin`, `Host`, `Forwarded`, `X-Forwarded-Proto`, `X-Forwarded-Host` and `X-Forwarded-Port` headers.
`static boolean`	`isValidOrigin(HttpRequest request, java.util.Collection<java.lang.String> allowedOrigins)` Check the given request origin against a list of allowed origins.
`static MultiValueMap<java.lang.String,java.lang.String>`	`parseMatrixVariables(java.lang.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, java.lang.String name, java.lang.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 java.lang.String INCLUDE_REQUEST_URI_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attribute for include request URI.
    If included via a RequestDispatcher, the current resource will see the originating request. Its own request URI is exposed as a request attribute.
    
    See Also:
    
    Constant Field Values
  - INCLUDE_CONTEXT_PATH_ATTRIBUTE
```
public static final java.lang.String INCLUDE_CONTEXT_PATH_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attribute for include context path.
    If included via a RequestDispatcher, the current resource will see the originating context path. Its own context path is exposed as a request attribute.
    
    See Also:
    
    Constant Field Values
  - INCLUDE_SERVLET_PATH_ATTRIBUTE
```
public static final java.lang.String INCLUDE_SERVLET_PATH_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attribute for include servlet path.
    If included via a RequestDispatcher, the current resource will see the originating servlet path. Its own servlet path is exposed as a request attribute.
    
    See Also:
    
    Constant Field Values
  - INCLUDE_PATH_INFO_ATTRIBUTE
```
public static final java.lang.String INCLUDE_PATH_INFO_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attribute for include path info.
    If included via a RequestDispatcher, the current resource will see the originating path info. Its own path info is exposed as a request attribute.
    
    See Also:
    
    Constant Field Values
  - INCLUDE_QUERY_STRING_ATTRIBUTE
```
public static final java.lang.String INCLUDE_QUERY_STRING_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attribute for include query string.
    If included via a RequestDispatcher, the current resource will see the originating query string. Its own query string is exposed as a request attribute.
    
    See Also:
    
    Constant Field Values
  - FORWARD_REQUEST_URI_ATTRIBUTE
```
public static final java.lang.String FORWARD_REQUEST_URI_ATTRIBUTE
```
    Standard Servlet 2.4+ spec request attribute for forward request URI.
    If forwarded to via a RequestDispatcher, the current resource will see its own request URI. The originating request URI is exposed as a request attribute.
    
    See Also:
    
    Constant Field Values
  - FORWARD_CONTEXT_PATH_ATTRIBUTE
```
public static final java.lang.String FORWARD_CONTEXT_PATH_ATTRIBUTE
```
    Standard Servlet 2.4+ spec request attribute for forward context path.
    If forwarded to via a RequestDispatcher, the current resource will see its own context path. The originating context path is exposed as a request attribute.
    
    See Also:
    
    Constant Field Values
  - FORWARD_SERVLET_PATH_ATTRIBUTE
```
public static final java.lang.String FORWARD_SERVLET_PATH_ATTRIBUTE
```
    Standard Servlet 2.4+ spec request attribute for forward servlet path.
    If forwarded to via a RequestDispatcher, the current resource will see its own servlet path. The originating servlet path is exposed as a request attribute.
    
    See Also:
    
    Constant Field Values
  - FORWARD_PATH_INFO_ATTRIBUTE
```
public static final java.lang.String FORWARD_PATH_INFO_ATTRIBUTE
```
    Standard Servlet 2.4+ spec request attribute for forward path info.
    If forwarded to via a RequestDispatcher, the current resource will see its own path ingo. The originating path info is exposed as a request attribute.
    
    See Also:
    
    Constant Field Values
  - FORWARD_QUERY_STRING_ATTRIBUTE
```
public static final java.lang.String FORWARD_QUERY_STRING_ATTRIBUTE
```
    Standard Servlet 2.4+ spec request attribute for forward query string.
    If forwarded to via a RequestDispatcher, the current resource will see its own query string. The originating query string is exposed as a request attribute.
    
    See Also:
    
    Constant Field Values
  - ERROR_STATUS_CODE_ATTRIBUTE
```
public static final java.lang.String ERROR_STATUS_CODE_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attribute for error page status code.
    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 java.lang.String ERROR_EXCEPTION_TYPE_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attribute for error page exception type.
    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_MESSAGE_ATTRIBUTE
```
public static final java.lang.String ERROR_MESSAGE_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attribute for error page message.
    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_ATTRIBUTE
```
public static final java.lang.String ERROR_EXCEPTION_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attribute for error page exception.
    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_REQUEST_URI_ATTRIBUTE
```
public static final java.lang.String ERROR_REQUEST_URI_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attribute for error page request URI.
    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_SERVLET_NAME_ATTRIBUTE
```
public static final java.lang.String ERROR_SERVLET_NAME_ATTRIBUTE
```
    Standard Servlet 2.3+ spec request attribute for error page servlet name.
    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
  - CONTENT_TYPE_CHARSET_PREFIX
```
public static final java.lang.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 java.lang.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 java.lang.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 java.lang.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 java.lang.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 java.lang.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 java.lang.String DEFAULT_WEB_APP_ROOT_KEY
```
    Default web app root key: "webapp.root".
    
    See Also:
    
    Constant Field Values
  - SUBMIT_IMAGE_SUFFIXES
```
public static final java.lang.String[] SUBMIT_IMAGE_SUFFIXES
```
    Name suffixes in case of image buttons.
  - SESSION_MUTEX_ATTRIBUTE
```
public static final java.lang.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 java.lang.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 substitution with System.getProperty values, like log4j's "${key}" syntax within log file locations.
    
    Parameters:
    
    servletContext - the servlet context of the web application
    
    Throws:
    
    java.lang.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
  - 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)
  - getDefaultHtmlEscape
```
@Nullable
public static java.lang.Boolean getDefaultHtmlEscape(@Nullable
                                                               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 for the given application (null = no explicit default)
  - getResponseEncodedHtmlEscape
```
@Nullable
public static java.lang.Boolean getResponseEncodedHtmlEscape(@Nullable
                                                                       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 to be used for HTML escaping (null = no explicit default)
    
    Since:
    
    4.1.2
  - getTempDir
```
public static java.io.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 java.lang.String getRealPath(ServletContext servletContext,
                                           java.lang.String path)
                                    throws java.io.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:
    
    java.io.FileNotFoundException - if the path cannot be resolved to a resource
    
    See Also:
    
    ServletContext.getRealPath(java.lang.String)
  - getSessionId
```
@Nullable
public static java.lang.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
```
@Nullable
public static java.lang.Object getSessionAttribute(HttpServletRequest request,
                                                             java.lang.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 java.lang.Object getRequiredSessionAttribute(HttpServletRequest request,
                                                           java.lang.String name)
                                                    throws java.lang.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:
    
    java.lang.IllegalStateException - if the session attribute could not be found
  - setSessionAttribute
```
public static void setSessionAttribute(HttpServletRequest request,
                                       java.lang.String name,
                                       @Nullable
                                       java.lang.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
  - getSessionMutex
```
public static java.lang.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
```
@Nullable
public static <T> T getNativeRequest(ServletRequest request,
                                               @Nullable
                                               java.lang.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
```
@Nullable
public static <T> T getNativeResponse(ServletResponse response,
                                                @Nullable
                                                java.lang.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,
                                                java.lang.Throwable ex,
                                                @Nullable
                                                java.lang.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
  - getCookie
```
@Nullable
public static Cookie getCookie(HttpServletRequest request,
                                         java.lang.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,
                                         java.lang.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
```
@Nullable
public static java.lang.String findParameterValue(ServletRequest request,
                                                            java.lang.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
```
@Nullable
public static java.lang.String findParameterValue(java.util.Map<java.lang.String,?> parameters,
                                                            java.lang.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 java.util.Map<java.lang.String,java.lang.Object> getParametersStartingWith(ServletRequest request,
                                                                                         @Nullable
                                                                                         java.lang.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 - the 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()
  - parseMatrixVariables
```
public static MultiValueMap<java.lang.String,java.lang.String> parseMatrixVariables(java.lang.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,
                                    java.util.Collection<java.lang.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.
    Note: as of 5.1 this method ignores "Forwarded" and "X-Forwarded-*" headers that specify the client-originated address. Consider using the ForwardedHeaderFilter to extract and use, or to discard such headers.
    
    Returns:
    
    true if the request origin is valid, false otherwise
    
    Since:
    
    4.1.5
    
    See Also:
    
    RFC 6454: The Web Origin Concept
  - isSameOrigin
```
public static boolean isSameOrigin(HttpRequest request)
```
    Check if the request is a same-origin one, based on Origin, Host, Forwarded, X-Forwarded-Proto, X-Forwarded-Host and X-Forwarded-Port headers.
    Note: as of 5.1 this method ignores "Forwarded" and "X-Forwarded-*" headers that specify the client-originated address. Consider using the ForwardedHeaderFilter to extract and use, or to discard such headers.
    
    Returns:
    
    true if the request is a same-origin one, false in case of cross-origin request
    
    Since:
    
    4.2

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

getDefaultHtmlEscape

getResponseEncodedHtmlEscape

getTempDir

getRealPath

getSessionId

getSessionAttribute

getRequiredSessionAttribute

setSessionAttribute

getSessionMutex

getNativeRequest

getNativeResponse

isIncludeRequest

exposeErrorRequestAttributes

clearErrorRequestAttributes

getCookie

hasSubmitParameter

findParameterValue

findParameterValue

getParametersStartingWith

parseMatrixVariables

isValidOrigin

isSameOrigin