javax.servlet.ServletRequest Maven / Gradle / Ivy
/*
* Copyright (c) 1997-2018 Oracle and/or its affiliates and others.
* All rights reserved.
* Copyright 2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package javax.servlet;
import java.io.*;
import java.util.*;
/**
* Defines an object to provide client request information to a servlet. The
* servlet container creates a ServletRequest object and passes
* it as an argument to the servlet's service method.
*
* A ServletRequest object provides data including
* parameter name and values, attributes, and an input stream.
* Interfaces that extend ServletRequest can provide
* additional protocol-specific data (for example, HTTP data is
* provided by {@link javax.servlet.http.HttpServletRequest}.
*
* @author Various
*
* @see javax.servlet.http.HttpServletRequest
*
*/
public interface ServletRequest {
/**
* Returns the value of the named attribute as an Object,
* or null if no attribute of the given name exists.
*
*
Attributes can be set two ways. The servlet container may set
* attributes to make available custom information about a request.
* For example, for requests made using HTTPS, the attribute
* javax.servlet.request.X509Certificate can be used to
* retrieve information on the certificate of the client. Attributes
* can also be set programatically using
* {@link ServletRequest#setAttribute}. This allows information to be
* embedded into a request before a {@link RequestDispatcher} call.
*
*
Attribute names should follow the same conventions as package
* names. This specification reserves names matching java.*,
* javax.*, and sun.*.
*
* @param name a String specifying the name of the attribute
*
* @return an Object containing the value of the attribute,
* or null if the attribute does not exist
*/
public Object getAttribute(String name);
/**
* Returns an Enumeration containing the
* names of the attributes available to this request.
* This method returns an empty Enumeration
* if the request has no attributes available to it.
*
* @return an Enumeration of strings containing the names
* of the request's attributes
*/
public Enumeration getAttributeNames();
/**
* Returns the name of the character encoding used in the body of this
* request. This method returns null if no request encoding
* character encoding has been specified. The following methods for
* specifying the request character encoding are consulted, in decreasing
* order of priority: per request, per web app (using
* {@link ServletContext#setRequestCharacterEncoding}, deployment
* descriptor), and per container (for all web applications deployed in
* that container, using vendor specific configuration).
*
* @return a String containing the name of the character
* encoding, or null if the request does not specify a
* character encoding
*/
public String getCharacterEncoding();
/**
* Overrides the name of the character encoding used in the body of this
* request. This method must be called prior to reading request parameters
* or reading input using getReader(). Otherwise, it has no effect.
*
* @param env String containing the name of
* the character encoding.
*
* @throws UnsupportedEncodingException if this ServletRequest is still
* in a state where a character encoding may be set,
* but the specified encoding is invalid
*/
public void setCharacterEncoding(String env) throws UnsupportedEncodingException;
/**
* Returns the length, in bytes, of the request body and made available by
* the input stream, or -1 if the length is not known ir is greater than
* Integer.MAX_VALUE. For HTTP servlets,
* same as the value of the CGI variable CONTENT_LENGTH.
*
* @return an integer containing the length of the request body or -1 if
* the length is not known or is greater than Integer.MAX_VALUE.
*/
public int getContentLength();
/**
* Returns the length, in bytes, of the request body and made available by
* the input stream, or -1 if the length is not known. For HTTP servlets,
* same as the value of the CGI variable CONTENT_LENGTH.
*
* @return a long containing the length of the request body or -1L if
* the length is not known
*
* @since Servlet 3.1
*/
public long getContentLengthLong();
/**
* Returns the MIME type of the body of the request, or
* null if the type is not known. For HTTP servlets,
* same as the value of the CGI variable CONTENT_TYPE.
*
* @return a String containing the name of the MIME type
* of the request, or null if the type is not known
*/
public String getContentType();
/**
* Retrieves the body of the request as binary data using
* a {@link ServletInputStream}. Either this method or
* {@link #getReader} may be called to read the body, not both.
*
* @return a {@link ServletInputStream} object containing
* the body of the request
*
* @exception IllegalStateException if the {@link #getReader} method
* has already been called for this request
*
* @exception IOException if an input or output exception occurred
*/
public ServletInputStream getInputStream() throws IOException;
/**
* Returns the value of a request parameter as a String,
* or null if the parameter does not exist. Request parameters
* are extra information sent with the request. For HTTP servlets,
* parameters are contained in the query string or posted form data.
*
* You should only use this method when you are sure the
* parameter has only one value. If the parameter might have
* more than one value, use {@link #getParameterValues}.
*
*
If you use this method with a multivalued
* parameter, the value returned is equal to the first value
* in the array returned by getParameterValues.
*
*
If the parameter data was sent in the request body, such as occurs
* with an HTTP POST request, then reading the body directly via {@link
* #getInputStream} or {@link #getReader} can interfere
* with the execution of this method.
*
* @param name a String specifying the name of the parameter
*
* @return a String representing the single value of
* the parameter
*
* @see #getParameterValues
*/
public String getParameter(String name);
/**
*
* Returns an Enumeration of String
* objects containing the names of the parameters contained
* in this request. If the request has
* no parameters, the method returns an empty Enumeration.
*
* @return an Enumeration of String
* objects, each String containing the name of
* a request parameter; or an empty Enumeration
* if the request has no parameters
*/
public Enumeration getParameterNames();
/**
* Returns an array of String objects containing
* all of the values the given request parameter has, or
* null if the parameter does not exist.
*
* If the parameter has a single value, the array has a length
* of 1.
*
* @param name a String containing the name of
* the parameter whose value is requested
*
* @return an array of String objects
* containing the parameter's values
*
* @see #getParameter
*/
public String[] getParameterValues(String name);
/**
* Returns a java.util.Map of the parameters of this request.
*
*
Request parameters are extra information sent with the request.
* For HTTP servlets, parameters are contained in the query string or
* posted form data.
*
* @return an immutable java.util.Map containing parameter names as
* keys and parameter values as map values. The keys in the parameter
* map are of type String. The values in the parameter map are of type
* String array.
*/
public Map getParameterMap();
/**
* Returns the name and version of the protocol the request uses
* in the form protocol/majorVersion.minorVersion, for
* example, HTTP/1.1. For HTTP servlets, the value
* returned is the same as the value of the CGI variable
* SERVER_PROTOCOL.
*
* @return a String containing the protocol
* name and version number
*/
public String getProtocol();
/**
* Returns the name of the scheme used to make this request,
* for example,
* http, https, or ftp.
* Different schemes have different rules for constructing URLs,
* as noted in RFC 1738.
*
* @return a String containing the name
* of the scheme used to make this request
*/
public String getScheme();
/**
* Returns the host name of the server to which the request was sent.
* It is the value of the part before ":" in the Host
* header value, if any, or the resolved server name, or the server IP
* address.
*
* @return a String containing the name of the server
*/
public String getServerName();
/**
* Returns the port number to which the request was sent.
* It is the value of the part after ":" in the Host
* header value, if any, or the server port where the client connection
* was accepted on.
*
* @return an integer specifying the port number
*/
public int getServerPort();
/**
* Retrieves the body of the request as character data using
* a BufferedReader. The reader translates the character
* data according to the character encoding used on the body.
* Either this method or {@link #getInputStream} may be called to read the
* body, not both.
*
* @return a BufferedReader containing the body of the request
*
* @exception UnsupportedEncodingException if the character set encoding
* used is not supported and the text cannot be decoded
*
* @exception IllegalStateException if {@link #getInputStream} method
* has been called on this request
*
* @exception IOException if an input or output exception occurred
*
* @see #getInputStream
*/
public BufferedReader getReader() throws IOException;
/**
* Returns the Internet Protocol (IP) address of the client
* or last proxy that sent the request.
* For HTTP servlets, same as the value of the
* CGI variable REMOTE_ADDR.
*
* @return a String containing the
* IP address of the client that sent the request
*/
public String getRemoteAddr();
/**
* Returns the fully qualified name of the client
* or the last proxy that sent the request.
* If the engine cannot or chooses not to resolve the hostname
* (to improve performance), this method returns the dotted-string form of
* the IP address. For HTTP servlets, same as the value of the CGI variable
* REMOTE_HOST.
*
* @return a String containing the fully
* qualified name of the client
*/
public String getRemoteHost();
/**
* Stores an attribute in this request.
* Attributes are reset between requests. This method is most
* often used in conjunction with {@link RequestDispatcher}.
*
* Attribute names should follow the same conventions as
* package names.
*
If the object passed in is null, the effect is the same as
* calling {@link #removeAttribute}.
*
It is warned that when the request is dispatched from the
* servlet resides in a different web application by
* RequestDispatcher, the object set by this method
* may not be correctly retrieved in the caller servlet.
*
* @param name a String specifying
* the name of the attribute
*
* @param o the Object to be stored
*
*/
public void setAttribute(String name, Object o);
/**
*
* Removes an attribute from this request. This method is not
* generally needed as attributes only persist as long as the request
* is being handled.
*
*
Attribute names should follow the same conventions as
* package names. Names beginning with java.*,
* javax.*, and com.sun.*, are
* reserved for use by Sun Microsystems.
*
* @param name a String specifying
* the name of the attribute to remove
*/
public void removeAttribute(String name);
/**
* Returns the preferred Locale that the client will
* accept content in, based on the Accept-Language header.
* If the client request doesn't provide an Accept-Language header,
* this method returns the default locale for the server.
*
* @return the preferred Locale for the client
*/
public Locale getLocale();
/**
* Returns an Enumeration of Locale objects
* indicating, in decreasing order starting with the preferred locale, the
* locales that are acceptable to the client based on the Accept-Language
* header.
* If the client request doesn't provide an Accept-Language header,
* this method returns an Enumeration containing one
* Locale, the default locale for the server.
*
* @return an Enumeration of preferred
* Locale objects for the client
*/
public Enumeration getLocales();
/**
*
* Returns a boolean indicating whether this request was made using a
* secure channel, such as HTTPS.
*
* @return a boolean indicating if the request was made using a
* secure channel
*/
public boolean isSecure();
/**
*
* Returns a {@link RequestDispatcher} object that acts as a wrapper for
* the resource located at the given path.
* A RequestDispatcher object can be used to forward
* a request to the resource or to include the resource in a response.
* The resource can be dynamic or static.
*
* The pathname specified may be relative, although it cannot extend
* outside the current servlet context. If the path begins with
* a "/" it is interpreted as relative to the current context root.
* This method returns null if the servlet container
* cannot return a RequestDispatcher.
*
*
The difference between this method and {@link
* ServletContext#getRequestDispatcher} is that this method can take a
* relative path.
*
* @param path a String specifying the pathname
* to the resource. If it is relative, it must be
* relative against the current servlet.
*
* @return a RequestDispatcher object that acts as a
* wrapper for the resource at the specified path,
* or null if the servlet container cannot
* return a RequestDispatcher
*
* @see RequestDispatcher
* @see ServletContext#getRequestDispatcher
*/
public RequestDispatcher getRequestDispatcher(String path);
/**
* @param path the path for which the real path is to be returned.
* @return the real path, or null if the
* translation cannot be performed.
* @deprecated As of Version 2.1 of the Java Servlet API,
* use {@link ServletContext#getRealPath} instead.
*/
public String getRealPath(String path);
/**
* Returns the Internet Protocol (IP) source port of the client
* or last proxy that sent the request.
*
* @return an integer specifying the port number
*
* @since Servlet 2.4
*/
public int getRemotePort();
/**
* Returns the host name of the Internet Protocol (IP) interface on
* which the request was received.
*
* @return a String containing the host
* name of the IP on which the request was received.
*
* @since Servlet 2.4
*/
public String getLocalName();
/**
* Returns the Internet Protocol (IP) address of the interface on
* which the request was received.
*
* @return a String containing the
* IP address on which the request was received.
*
* @since Servlet 2.4
*/
public String getLocalAddr();
/**
* Returns the Internet Protocol (IP) port number of the interface
* on which the request was received.
*
* @return an integer specifying the port number
*
* @since Servlet 2.4
*/
public int getLocalPort();
/**
* Gets the servlet context to which this ServletRequest was last
* dispatched.
*
* @return the servlet context to which this ServletRequest was last
* dispatched
*
* @since Servlet 3.0
*/
public ServletContext getServletContext();
/**
* Puts this request into asynchronous mode, and initializes its
* {@link AsyncContext} with the original (unwrapped) ServletRequest
* and ServletResponse objects.
*
*
Calling this method will cause committal of the associated
* response to be delayed until {@link AsyncContext#complete} is
* called on the returned {@link AsyncContext}, or the asynchronous
* operation has timed out.
*
*
Calling {@link AsyncContext#hasOriginalRequestAndResponse()} on
* the returned AsyncContext will return true. Any filters
* invoked in the outbound direction after this request was put
* into asynchronous mode may use this as an indication that any request
* and/or response wrappers that they added during their inbound
* invocation need not stay around for the duration of the asynchronous
* operation, and therefore any of their associated resources may be
* released.
*
*
This method clears the list of {@link AsyncListener} instances
* (if any) that were registered with the AsyncContext returned by the
* previous call to one of the startAsync methods, after calling each
* AsyncListener at its {@link AsyncListener#onStartAsync onStartAsync}
* method.
*
*
Subsequent invocations of this method, or its overloaded
* variant, will return the same AsyncContext instance, reinitialized
* as appropriate.
*
* @return the (re)initialized AsyncContext
*
* @throws IllegalStateException if this request is within the scope of
* a filter or servlet that does not support asynchronous operations
* (that is, {@link #isAsyncSupported} returns false),
* or if this method is called again without any asynchronous dispatch
* (resulting from one of the {@link AsyncContext#dispatch} methods),
* is called outside the scope of any such dispatch, or is called again
* within the scope of the same dispatch, or if the response has
* already been closed
*
* @see AsyncContext#dispatch()
* @since Servlet 3.0
*/
public AsyncContext startAsync() throws IllegalStateException;
/**
* Puts this request into asynchronous mode, and initializes its
* {@link AsyncContext} with the given request and response objects.
*
*
The ServletRequest and ServletResponse arguments must be
* the same instances, or instances of {@link ServletRequestWrapper} and
* {@link ServletResponseWrapper} that wrap them, that were passed to the
* {@link Servlet#service service} method of the Servlet or the
* {@link Filter#doFilter doFilter} method of the Filter, respectively,
* in whose scope this method is being called.
*
*
Calling this method will cause committal of the associated
* response to be delayed until {@link AsyncContext#complete} is
* called on the returned {@link AsyncContext}, or the asynchronous
* operation has timed out.
*
*
Calling {@link AsyncContext#hasOriginalRequestAndResponse()} on
* the returned AsyncContext will return false,
* unless the passed in ServletRequest and ServletResponse arguments
* are the original ones or do not carry any application-provided wrappers.
* Any filters invoked in the outbound direction after this
* request was put into asynchronous mode may use this as an indication
* that some of the request and/or response wrappers that they added
* during their inbound invocation may need to stay in place for
* the duration of the asynchronous operation, and their associated
* resources may not be released.
* A ServletRequestWrapper applied during the inbound
* invocation of a filter may be released by the outbound
* invocation of the filter only if the given servletRequest,
* which is used to initialize the AsyncContext and will be returned by
* a call to {@link AsyncContext#getRequest()}, does not contain said
* ServletRequestWrapper. The same holds true for ServletResponseWrapper
* instances.
*
*
This method clears the list of {@link AsyncListener} instances
* (if any) that were registered with the AsyncContext returned by the
* previous call to one of the startAsync methods, after calling each
* AsyncListener at its {@link AsyncListener#onStartAsync onStartAsync}
* method.
*
*
Subsequent invocations of this method, or its zero-argument
* variant, will return the same AsyncContext instance, reinitialized
* as appropriate. If a call to this method is followed by a call to its
* zero-argument variant, the specified (and possibly wrapped) request
* and response objects will remain locked in on the returned
* AsyncContext.
*
* @param servletRequest the ServletRequest used to initialize the
* AsyncContext
* @param servletResponse the ServletResponse used to initialize the
* AsyncContext
*
* @return the (re)initialized AsyncContext
*
* @throws IllegalStateException if this request is within the scope of
* a filter or servlet that does not support asynchronous operations
* (that is, {@link #isAsyncSupported} returns false),
* or if this method is called again without any asynchronous dispatch
* (resulting from one of the {@link AsyncContext#dispatch} methods),
* is called outside the scope of any such dispatch, or is called again
* within the scope of the same dispatch, or if the response has
* already been closed
*
* @since Servlet 3.0
*/
public AsyncContext startAsync(ServletRequest servletRequest,
ServletResponse servletResponse)
throws IllegalStateException;
/**
* Checks if this request has been put into asynchronous mode.
*
*
A ServletRequest is put into asynchronous mode by calling
* {@link #startAsync} or
* {@link #startAsync(ServletRequest,ServletResponse)} on it.
*
*
This method returns false if this request was
* put into asynchronous mode, but has since been dispatched using
* one of the {@link AsyncContext#dispatch} methods or released
* from asynchronous mode via a call to {@link AsyncContext#complete}.
*
* @return true if this request has been put into asynchronous mode,
* false otherwise
*
* @since Servlet 3.0
*/
public boolean isAsyncStarted();
/**
* Checks if this request supports asynchronous operation.
*
*
Asynchronous operation is disabled for this request if this request
* is within the scope of a filter or servlet that has not been annotated
* or flagged in the deployment descriptor as being able to support
* asynchronous handling.
*
* @return true if this request supports asynchronous operation, false
* otherwise
*
* @since Servlet 3.0
*/
public boolean isAsyncSupported();
/**
* Gets the AsyncContext that was created or reinitialized by the
* most recent invocation of {@link #startAsync} or
* {@link #startAsync(ServletRequest,ServletResponse)} on this request.
*
* @return the AsyncContext that was created or reinitialized by the
* most recent invocation of {@link #startAsync} or
* {@link #startAsync(ServletRequest,ServletResponse)} on
* this request
*
* @throws IllegalStateException if this request has not been put
* into asynchronous mode, i.e., if neither {@link #startAsync} nor
* {@link #startAsync(ServletRequest,ServletResponse)} has been called
*
* @since Servlet 3.0
*/
public AsyncContext getAsyncContext();
/**
* Gets the dispatcher type of this request.
*
*
The dispatcher type of a request is used by the container
* to select the filters that need to be applied to the request:
* Only filters with matching dispatcher type and url patterns will
* be applied.
*
*
Allowing a filter that has been configured for multiple
* dispatcher types to query a request for its dispatcher type
* allows the filter to process the request differently depending on
* its dispatcher type.
*
*
The initial dispatcher type of a request is defined as
* DispatcherType.REQUEST. The dispatcher type of a request
* dispatched via {@link RequestDispatcher#forward(ServletRequest,
* ServletResponse)} or {@link RequestDispatcher#include(ServletRequest,
* ServletResponse)} is given as DispatcherType.FORWARD or
* DispatcherType.INCLUDE, respectively, while the
* dispatcher type of an asynchronous request dispatched via
* one of the {@link AsyncContext#dispatch} methods is given as
* DispatcherType.ASYNC. Finally, the dispatcher type of a
* request dispatched to an error page by the container's error handling
* mechanism is given as DispatcherType.ERROR.
*
* @return the dispatcher type of this request
*
* @see DispatcherType
*
* @since Servlet 3.0
*/
public DispatcherType getDispatcherType();
}