javax.servlet.ServletRequest Maven / Gradle / Ivy
/*
* 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.
*/
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 {@link javax.servlet.http.HttpServletRequest}.
*
* @author Various
* @version $Version$
*
* @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 the request
* does not specify a character encoding
*
*
* @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().
*
*
* @param env a String 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.
*
* @return an integer containing the length of the
* request body or -1 if the length is not known
*
*/
public int getContentLength();
/**
* 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. Names beginning with java.*,
* javax.*, and com.sun.*, are
* reserved for use by Sun Microsystems.
*
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);
/**
*
* @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 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 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 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 2.4
*/
public int getLocalPort();
}