/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
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package javax.servlet;

import java.io.BufferedReader;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Locale;
import java.util.Map;

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 HttpServletRequest.

See Also:
/** * Defines an object to provide client request information to a servlet. The * servlet container creates a <code>ServletRequest</code> object and passes it * as an argument to the servlet's <code>service</code> method. * <p> * A <code>ServletRequest</code> object provides data including parameter name * and values, attributes, and an input stream. Interfaces that extend * <code>ServletRequest</code> can provide additional protocol-specific data * (for example, HTTP data is provided by * {@link javax.servlet.http.HttpServletRequest}. * * @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 programmatically using setAttribute. This allows information to be embedded into a request before a RequestDispatcher call.

Attribute names should follow the same conventions as package names. Names beginning with java.* and javax.* are reserved for use by the Servlet specification. Names beginning with sun.*, com.sun.*, oracle.* and com.oracle.*) are reserved for use by Oracle Corporation.

Params:
  • name – a String specifying the name of the attribute
Returns:an Object containing the value of the attribute, or null if the attribute does not exist
/** * Returns the value of the named attribute as an <code>Object</code>, or * <code>null</code> if no attribute of the given name exists. * <p> * 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 * <code>javax.servlet.request.X509Certificate</code> can be used to * retrieve information on the certificate of the client. Attributes can * also be set programmatically using {@link ServletRequest#setAttribute}. * This allows information to be embedded into a request before a * {@link RequestDispatcher} call. * <p> * Attribute names should follow the same conventions as package names. * Names beginning with <code>java.*</code> and <code>javax.*</code> are * reserved for use by the Servlet specification. Names beginning with * <code>sun.*</code>, <code>com.sun.*</code>, <code>oracle.*</code> and * <code>com.oracle.*</code>) are reserved for use by Oracle Corporation. * * @param name * a <code>String</code> specifying the name of the attribute * @return an <code>Object</code> containing the value of the attribute, or * <code>null</code> 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.
Returns:an Enumeration of strings containing the names of the request's attributes
/** * Returns an <code>Enumeration</code> containing the names of the * attributes available to this request. This method returns an empty * <code>Enumeration</code> if the request has no attributes available to * it. * * @return an <code>Enumeration</code> of strings containing the names of the * request's attributes */
public Enumeration<String> getAttributeNames();
Returns the name of the character encoding used in the body of this request. This method returns null if the no character encoding has been specified. The following priority order is used to determine the specified encoding:
  1. per request
  2. web application default via the deployment descriptor or ServletContext.setRequestCharacterEncoding(String)
  3. container default via container specific configuration
Returns:a String containing the name of the character encoding, or null if the request does not specify a character encoding
/** * Returns the name of the character encoding used in the body of this * request. This method returns <code>null</code> if the no character * encoding has been specified. The following priority order is used to * determine the specified encoding: * <ol> * <li>per request</li> * <li>web application default via the deployment descriptor or * {@link ServletContext#setRequestCharacterEncoding(String)}</li> * <li>container default via container specific configuration</li> * </ol> * * @return a <code>String</code> containing the name of the character * encoding, or <code>null</code> 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().
Params:
  • env – a String containing the name of the character encoding.
Throws:
/** * 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(). * * @param env * a <code>String</code> containing the name of the character * encoding. * @throws java.io.UnsupportedEncodingException * if this is not a valid encoding */
public void setCharacterEncoding(String env) throws java.io.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. For HTTP servlets, same as the value of the CGI variable CONTENT_LENGTH.
Returns:an integer containing the length of the request body or -1 if the length is not known or is greater than Integer.MAX_VALUE
/** * 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 an integer containing the length of the request body or -1 if the * length is not known or is greater than {@link 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.
Returns:a long integer containing the length of the request body or -1 if the length is not known
Since:Servlet 3.1
/** * 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 integer containing the length of the request body or -1 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.
Returns:a String containing the name of the MIME type of the request, or null if the type is not known
/** * Returns the MIME type of the body of the request, or <code>null</code> if * the type is not known. For HTTP servlets, same as the value of the CGI * variable CONTENT_TYPE. * * @return a <code>String</code> 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 ServletInputStream. Either this method or getReader may be called to read the body, not both.
Throws:
Returns:a ServletInputStream object containing the body of the request
/** * 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 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 getInputStream or getReader can interfere with the execution of this method.

Params:
  • name – a String specifying the name of the parameter
See Also:
Returns:a String representing the single value of the parameter
/** * Returns the value of a request parameter as a <code>String</code>, or * <code>null</code> 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. * <p> * 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}. * <p> * If you use this method with a multivalued parameter, the value returned * is equal to the first value in the array returned by * <code>getParameterValues</code>. * <p> * 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 <code>String</code> specifying the name of the parameter * @return a <code>String</code> 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.
Returns:an Enumeration of String objects, each String containing the name of a request parameter; or an empty Enumeration if the request has no parameters
/** * Returns an <code>Enumeration</code> of <code>String</code> objects * containing the names of the parameters contained in this request. If the * request has no parameters, the method returns an empty * <code>Enumeration</code>. * * @return an <code>Enumeration</code> of <code>String</code> objects, each * <code>String</code> containing the name of a request parameter; * or an empty <code>Enumeration</code> if the request has no * parameters */
public Enumeration<String> 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.

Params:
  • name – a String containing the name of the parameter whose value is requested
See Also:
Returns:an array of String objects containing the parameter's values
/** * Returns an array of <code>String</code> objects containing all of the * values the given request parameter has, or <code>null</code> if the * parameter does not exist. * <p> * If the parameter has a single value, the array has a length of 1. * * @param name * a <code>String</code> containing the name of the parameter * whose value is requested * @return an array of <code>String</code> 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.
Returns: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.
/** * 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<String, String[]> 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.
Returns:a String containing the protocol name and version number
/** * Returns the name and version of the protocol the request uses in the form * <i>protocol/majorVersion.minorVersion</i>, for example, HTTP/1.1. For * HTTP servlets, the value returned is the same as the value of the CGI * variable <code>SERVER_PROTOCOL</code>. * * @return a <code>String</code> 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.
Returns:a String containing the name of the scheme used to make this request
/** * Returns the name of the scheme used to make this request, for example, * <code>http</code>, <code>https</code>, or <code>ftp</code>. Different * schemes have different rules for constructing URLs, as noted in RFC 1738. * * @return a <code>String</code> 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.
Returns:a String containing the name of the server
/** * Returns the host name of the server to which the request was sent. It is * the value of the part before ":" in the <code>Host</code> header value, * if any, or the resolved server name, or the server IP address. * * @return a <code>String</code> 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.
Returns:an integer specifying the port number
/** * Returns the port number to which the request was sent. It is the value of * the part after ":" in the <code>Host</code> 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 getInputStream may be called to read the body, not both.
Throws:
See Also:
Returns:a BufferedReader containing the body of the request
/** * Retrieves the body of the request as character data using a * <code>BufferedReader</code>. 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 <code>BufferedReader</code> containing the body of the request * @exception java.io.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.
Returns:a String containing the IP address of the client that sent the request
/** * 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 <code>REMOTE_ADDR</code>. * * @return a <code>String</code> 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.
Returns:a String containing the fully qualified name of the client
/** * 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 <code>REMOTE_HOST</code>. * * @return a <code>String</code> 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 RequestDispatcher.

Attribute names should follow the same conventions as package names. Names beginning with java.* and javax.* are reserved for use by the Servlet specification. Names beginning with sun.*, com.sun.*, oracle.* and com.oracle.*) are reserved for use by Oracle Corporation.
If the object passed in is null, the effect is the same as calling 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.

Params:
  • name – a String specifying the name of the attribute
  • o – the Object to be stored
/** * Stores an attribute in this request. Attributes are reset between * requests. This method is most often used in conjunction with * {@link RequestDispatcher}. * <p> * Attribute names should follow the same conventions as package names. * Names beginning with <code>java.*</code> and <code>javax.*</code> are * reserved for use by the Servlet specification. Names beginning with * <code>sun.*</code>, <code>com.sun.*</code>, <code>oracle.*</code> and * <code>com.oracle.*</code>) are reserved for use by Oracle Corporation. * <br> * If the object passed in is null, the effect is the same as calling * {@link #removeAttribute}. <br> * It is warned that when the request is dispatched from the servlet resides * in a different web application by <code>RequestDispatcher</code>, the * object set by this method may not be correctly retrieved in the caller * servlet. * * @param name * a <code>String</code> specifying the name of the attribute * @param o * the <code>Object</code> 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.* and javax.* are reserved for use by the Servlet specification. Names beginning with sun.*, com.sun.*, oracle.* and com.oracle.*) are reserved for use by Oracle Corporation.

Params:
  • name – a String specifying the name of the attribute to remove
/** * Removes an attribute from this request. This method is not generally * needed as attributes only persist as long as the request is being * handled. * <p> * Attribute names should follow the same conventions as package names. * Names beginning with <code>java.*</code> and <code>javax.*</code> are * reserved for use by the Servlet specification. Names beginning with * <code>sun.*</code>, <code>com.sun.*</code>, <code>oracle.*</code> and * <code>com.oracle.*</code>) are reserved for use by Oracle Corporation. * * @param name * a <code>String</code> 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.
Returns:the preferred Locale for the client
/** * Returns the preferred <code>Locale</code> 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 <code>Locale</code> 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.
Returns:an Enumeration of preferred Locale objects for the client
/** * Returns an <code>Enumeration</code> of <code>Locale</code> 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 <code>Enumeration</code> containing one * <code>Locale</code>, the default locale for the server. * * @return an <code>Enumeration</code> of preferred <code>Locale</code> * objects for the client */
public Enumeration<Locale> getLocales();
Returns a boolean indicating whether this request was made using a secure channel, such as HTTPS.
Returns:a boolean indicating if the request was made using a secure channel
/** * 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 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 ServletContext.getRequestDispatcher is that this method can take a relative path.

Params:
  • path – a String specifying the pathname to the resource. If it is relative, it must be relative against the current servlet.
See Also:
Returns: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
/** * Returns a {@link RequestDispatcher} object that acts as a wrapper for the * resource located at the given path. A <code>RequestDispatcher</code> * 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. * <p> * 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 * <code>null</code> if the servlet container cannot return a * <code>RequestDispatcher</code>. * <p> * The difference between this method and * {@link ServletContext#getRequestDispatcher} is that this method can take * a relative path. * * @param path * a <code>String</code> specifying the pathname to the resource. * If it is relative, it must be relative against the current * servlet. * @return a <code>RequestDispatcher</code> object that acts as a wrapper for * the resource at the specified path, or <code>null</code> if the * servlet container cannot return a <code>RequestDispatcher</code> * @see RequestDispatcher * @see ServletContext#getRequestDispatcher */
public RequestDispatcher getRequestDispatcher(String path);
Params:
  • path – The virtual path to be converted to a real path
Returns:ServletContext.getRealPath(String)
Deprecated:As of Version 2.1 of the Java Servlet API, use ServletContext.getRealPath instead.
/** * @param path The virtual path to be converted to a real path * @return {@link ServletContext#getRealPath(String)} * @deprecated As of Version 2.1 of the Java Servlet API, use * {@link ServletContext#getRealPath} instead. */
@Deprecated public String getRealPath(String path);
Returns the Internet Protocol (IP) source port of the client or last proxy that sent the request.
Returns:an integer specifying the port number
Since:Servlet 2.4
/** * 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.
Returns:a String containing the host name of the IP on which the request was received.
Since:Servlet 2.4
/** * Returns the host name of the Internet Protocol (IP) interface on which * the request was received. * * @return a <code>String</code> 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.
Returns:a String containing the IP address on which the request was received.
Since:Servlet 2.4
/** * Returns the Internet Protocol (IP) address of the interface on which the * request was received. * * @return a <code>String</code> 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.
Returns:an integer specifying the port number
Since:Servlet 2.4
/** * 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();
Returns:TODO
Since:Servlet 3.0 TODO SERVLET3 - Add comments
/** * @return TODO * @since Servlet 3.0 TODO SERVLET3 - Add comments */
public ServletContext getServletContext();
Throws:
Returns:TODO
Since:Servlet 3.0 TODO SERVLET3 - Add comments
/** * @return TODO * @throws IllegalStateException If async is not supported for this request * @since Servlet 3.0 TODO SERVLET3 - Add comments */
public AsyncContext startAsync() throws IllegalStateException;
Params:
  • servletRequest – The ServletRequest with which to initialise the asynchronous context
  • servletResponse – The ServletResponse with which to initialise the asynchronous context
Throws:
Returns:TODO
Since:Servlet 3.0 TODO SERVLET3 - Add comments
/** * @param servletRequest The ServletRequest with which to initialise the * asynchronous context * @param servletResponse The ServletResponse with which to initialise the * asynchronous context * @return TODO * @throws IllegalStateException If async is not supported for this request * @since Servlet 3.0 TODO SERVLET3 - Add comments */
public AsyncContext startAsync(ServletRequest servletRequest, ServletResponse servletResponse) throws IllegalStateException;
Returns:TODO
Since:Servlet 3.0 TODO SERVLET3 - Add comments
/** * @return TODO * @since Servlet 3.0 TODO SERVLET3 - Add comments */
public boolean isAsyncStarted();
Returns:TODO
Since:Servlet 3.0 TODO SERVLET3 - Add comments
/** * @return TODO * @since Servlet 3.0 TODO SERVLET3 - Add comments */
public boolean isAsyncSupported();
Get the current AsyncContext.
Throws:
  • IllegalStateException – if the request is not in asynchronous mode (i.e. @link #isAsyncStarted() is false)
Returns:The current AsyncContext
Since:Servlet 3.0
/** * Get the current AsyncContext. * * @return The current AsyncContext * * @throws IllegalStateException if the request is not in asynchronous mode * (i.e. @link #isAsyncStarted() is {@code false}) * * @since Servlet 3.0 */
public AsyncContext getAsyncContext();
Returns:TODO
Since:Servlet 3.0 TODO SERVLET3 - Add comments
/** * @return TODO * @since Servlet 3.0 TODO SERVLET3 - Add comments */
public DispatcherType getDispatcherType(); }