Java-HttpServletRequest

//继承了ServletRequest接口，给servlet提供Request请求信息，servlet 容器会创建以后HttpServletRequest对象
//并把它作为一个参数给service函数
public interface HttpServletRequest extends ServletRequest {

/**
* String identifier for Basic authentication. Value "BASIC"
*/
public static final String BASIC_AUTH = "BASIC";
/**
* String identifier for Form authentication. Value "FORM"
*/
public static final String FORM_AUTH = "FORM";
/**
* String identifier for Client Certificate authentication. Value "CLIENT_CERT"
*/
public static final String CLIENT_CERT_AUTH = "CLIENT_CERT";
/**
* String identifier for Digest authentication. Value "DIGEST"
*/
public static final String DIGEST_AUTH = "DIGEST";

/**
* Returns the name of the authentication scheme used to protect
* the servlet. All servlet containers support basic, form and client
* certificate authentication, and may additionally support digest
* authentication.
* If the servlet is not authenticated <code>null</code> is returned.
* <p>Same as the value of the CGI variable AUTH_TYPE.
*/
//返回验证符，BASIC_AUTH、FORM_AUTH、 CLIENT_CERT_AUTH、 DIGEST_AUTH
public String getAuthType();
/**
* Returns an array containing all of the <code>Cookie</code>
* objects the client sent with this request.
* This method returns <code>null</code> if no cookies were sent.
* @return		an array of all the <code>Cookies</code>
*			included with this request, or <code>null</code>
*			if the request has no cookies
*/
//返回一个包含所有cookie的数组
public Cookie[] getCookies();
/**
* Returns the value of the specified request header
* as a <code>long</code> value that represents a
* <code>Date</code> object. Use this method with
* headers that contain dates, such as
* <code>If-Modified-Since</code>.
* <p>The date is returned as
* the number of milliseconds since January 1, 1970 GMT.
* The header name is case insensitive.
* <p>If the request did not have a header of the
* specified name, this method returns -1. If the header
* can't be converted to a date, the method throws
* an <code>IllegalArgumentException</code>.
* @param name		a <code>String</code> specifying the
*				name of the header
* @return			a <code>long</code> valuerepresenting the date specified
in the header expressed as the number of milliseconds since January 1, 1970 GMT,
*				or -1 if the named header	was not included with the
*/
//返回name的时间请求头部，没有值返回-1
public long getDateHeader(String name);
/**
* Returns the value of the specified request header
* as a <code>String</code>. If the request did not include a header
* of the specified name, this method returns <code>null</code>.
* If there are multiple headers with the same name, this method
* returns the first head in the request.
* The header name is case insensitive. You can use
* this method with any request header.
* @param name		a <code>String</code> specifying the	header name
* @return			a <code>String</code> containing the	value of the requested
*	header, or <code>null</code>if the request does not	have a header of that name
*/
//返回头部name的信息
public String getHeader(String name);
/**
* Returns all the values of the specified request header
* as an <code>Enumeration</code> of <code>String</code> objects.
* <p>Some headers, such as <code>Accept-Language</code> can be sent
* by clients as several headers each with a different value rather than
* sending the header as a comma separated list.
* <p>If the request did not include any headers
* of the specified name, this method returns an empty
* <code>Enumeration</code>.
* The header name is case insensitive. You can use
* this method with any request header.
* @param name		a <code>String</code> specifying the
*				header name
* @return			an <code>Enumeration</code> containing
*                  	the values of the requested header. If
*                  	the request does not have any headers of
*                  	that name return an empty
*                  	enumeration. If
*                  	the container does not allow access to
*                  	header information, return null
*/
//返回头部name的枚举
public Enumeration getHeaders(String name);
/**
* Returns an enumeration of all the header names
* this request contains. If the request has no
* headers, this method returns an empty enumeration.
* <p>Some servlet containers do not allow
* servlets to access headers using this method, in
* which case this method returns <code>null</code>
* @return			an enumeration of all the
*				header names sent with this
*				request; if the request has
*				no headers, an empty enumeration;
*				if the servlet container does not
*				allow servlets to use this method,
*/
//所有头部的name枚举
public Enumeration getHeaderNames();
/**
* Returns the value of the specified request header
* as an <code>int</code>. If the request does not have a header
* of the specified name, this method returns -1. If the
* header cannot be converted to an integer, this method
* throws a <code>NumberFormatException</code>.
* <p>The header name is case insensitive.
* @param name		a <code>String</code> specifying the name of a request header
* @return an integer expressing the value 	of the request header or -1	if the request doesn't have a	header of this name
* @exception	NumberFormatException		If the header value	can't be converted	to an <code>int</code>
*/
//头部name作为int返回
public int getIntHeader(String name);
/**
* Returns the name of the HTTP method with which this
* request was made, for example, GET, POST, or PUT.
* Same as the value of the CGI variable REQUEST_METHOD.
* @return			a <code>String</code>
*				specifying the name
*				of the method with which
*				this request was made
*/
//返回方法get,post,put
public String getMethod();
/**
* Returns any extra path information associated with
* the URL the client sent when it made this request.
* The extra path information follows the servlet path
* but precedes the query string and will start with
* a "/" character.
* <p>This method returns <code>null</code> if there
* was no extra path information.
* <p>Same as the value of the CGI variable PATH_INFO.
* @return		a <code>String</code>, decoded by the
*			web container, specifying
*			extra path information that comes
*			after the servlet path but before
*			the query string in the request URL;
*			or <code>null</code> if the URL does not have
*			any extra path information
*/
//返回路径信息
public String getPathInfo();
/**
* but before the query string, and translates it to a real
* path. Same as the value of the CGI variable PATH_TRANSLATED.
* <p>If the URL does not have any extra path information,
* this method returns <code>null</code> or the servlet container
* cannot translate the virtual path to a real path for any reason
* (such as when the web application is executed from an archive).
* The web container does not decode this string.
* @return		a <code>String</code> specifying the
*			real path, or <code>null</code> if
*			the URL does not have any extra path
*			information
*/
//
public String getPathTranslated();
/**
*
* Returns the portion of the request URI that indicates the context
* of the request.  The context path always comes first in a request
* URI.  The path starts with a "/" character but does not end with a "/"
* character.  For servlets in the default (root) context, this method
* returns "". The container does not decode this string.
* @return		a <code>String</code> specifying the
*			portion of the request URI that indicates the context
*			of the request
*/

public String getContextPath();
/**
*
* Returns the query string that is contained in the request
* URL after the path. This method returns <code>null</code>
* if the URL does not have a query string. Same as the value
* of the CGI variable QUERY_STRING.
* @return		a <code>String</code> containing the query
*			string or <code>null</code> if the URL
*			contains no query string. The value is not
*			decoded by the container.
*/
//请求中的参数值
public String getQueryString();
/**
* Returns the login of the user making this request, if the
* user has been authenticated, or <code>null</code> if the user
* has not been authenticated.
* Whether the user name is sent with each subsequent request
* depends on the browser and type of authentication. Same as the
* value of the CGI variable REMOTE_USER.
* @return		a <code>String</code> specifying the login
*			of the user making this request, or <code>null</code>
*			if the user login is not known
*/
//远程用户
public String getRemoteUser();
/**
* Returns a boolean indicating whether the authenticated user is included
* in the specified logical "role".  Roles and role membership can be
* defined using deployment descriptors.  If the user has not been
* authenticated, the method returns <code>false</code>.
* @param role		a <code>String</code> specifying the name
*				of the role
* @return		a <code>boolean</code> indicating whether
*			the user making this request belongs to a given role;
*			<code>false</code> if the user has not been
*			authenticated
*/
//用户角色判断
public boolean isUserInRole(String role);
/**
* Returns a <code>java.security.Principal</code> object containing
* the name of the current authenticated user. If the user has not been
* authenticated, the method returns <code>null</code>.
* @return		a <code>java.security.Principal</code> containing
*			the name of the user making this request;
*			<code>null</code> if the user has not been
*			authenticated
*/
//
public java.security.Principal getUserPrincipal();
/**
* Returns the session ID specified by the client. This may
* not be the same as the ID of the current valid session
* for this request.
* If the client did not specify a session ID, this method returns
* @return		a <code>String</code> specifying the session
*			ID, or <code>null</code> if the request did
*			not specify a session ID
* @see		#isRequestedSessionIdValid
*/
//获得客户端请求产生的session id
public String getRequestedSessionId();
/**
* Returns the part of this request's URL from the protocol
* name up to the query string in the first line of the HTTP request.
* The web container does not decode this String.
* For example:
* <table summary="Examples of Returned Values">
* <tr align=left><th>First line of HTTP request      </th>
* <th>     Returned Value</th>
* <tr><td>POST /some/path.html HTTP/1.1<td><td>/some/path.html
* <tr><td>GET http://foo.bar/a.html HTTP/1.0
* <td><td>/a.html
* <tr><td>HEAD /xyz?a=b HTTP/1.1<td><td>/xyz
* </table>
* <p>To reconstruct an URL with a scheme and host, use
* {@link HttpUtils#getRequestURL}.
* @return		a <code>String</code> containing
*			the part of the URL from the
*			protocol name up to the query string
* @see		HttpUtils#getRequestURL
*/
//获得请求URI
public String getRequestURI();
/**
* Reconstructs the URL the client used to make the request.
* The returned URL contains a protocol, server name, port
* number, and server path, but it does not include query
* string parameters.
* <p>Because this method returns a <code>StringBuffer</code>,
* not a string, you can modify the URL easily, for example,
* to append query parameters.
* <p>This method is useful for creating redirect messages
* and for reporting errors.
* @return		a <code>StringBuffer</code> object containing
*			the reconstructed URL
*/
//返回URL，不包括之前URL中的参数
public StringBuffer getRequestURL();
/**
* Returns the part of this request's URL that calls
* the servlet. This path starts with a "/" character
* and includes either the servlet name or a path to
* the servlet, but does not include any extra path
* information or a query string. Same as the value of
* the CGI variable SCRIPT_NAME.
* <p>This method will return an empty string ("") if the
* servlet used to process this request was matched using
* the "/*" pattern.
* @return		a <code>String</code> containing
*			the name or path of the servlet being
*			called, as specified in the request URL,
*			decoded, or an empty string if the servlet
*			used to process the request is matched
*			using the "/*" pattern.
*
*/
//获得URL中servlet路径部分
public String getServletPath();
/**
* Returns the current <code>HttpSession</code>
* associated with this request or, if there is no
* current session and <code>create</code> is true, returns
* a new session.
* <p>If <code>create</code> is <code>false</code>
* and the request has no valid <code>HttpSession</code>,
* this method returns <code>null</code>.
* <p>To make sure the session is properly maintained,
* you must call this method before
* the response is committed. If the container is using cookies
* to maintain session integrity and is asked to create a new session
* when the response is committed, an IllegalStateException is thrown.
* @param create	<code>true</code> to create
*			a new session for this request if necessary;
*			<code>false</code> to return <code>null</code>
*			if there's no current session
* @return 		the <code>HttpSession</code> associated
*			with this request or <code>null</code> if
* 			<code>create</code> is <code>false</code>
*			and the request has no valid session
* @see	#getSession()
*/
//获得httpSession,如果没有并且create为true则新建一个session
public HttpSession getSession(boolean create);
/**
* Returns the current session associated with this request,
* or if the request does not have a session, creates one.
* @return		the <code>HttpSession</code> associated
*			with this request
* @see	#getSession(boolean)
*/
//获得当前session，如果没有new
public HttpSession getSession();
/**
* Checks whether the requested session ID is still valid.
* @return			<code>true</code> if this
*				request has an id for a valid session
*				in the current session context;
*				<code>false</code> otherwise
* @see			#getRequestedSessionId
* @see			#getSession
* @see			HttpSessionContext
*/
//判断session id是否还有效
public boolean isRequestedSessionIdValid();
/**
* Checks whether the requested session ID came in as a cookie.
* @return			<code>true</code> if the session ID
*				came in as a
*				cookie; otherwise, <code>false</code>
* @see			#getSession
*/
//session id 来自cookie
public boolean isRequestedSessionIdFromCookie();
/**
* Checks whether the requested session ID came in as part of the
* request URL.
* @return			<code>true</code> if the session ID
*				came in as part of a URL; otherwise,
*				<code>false</code>
* @see			#getSession
*/
//session id 作为请求URL的一部分
public boolean isRequestedSessionIdFromURL();
/**
* @deprecated		As of Version 2.1 of the Java Servlet
*				API, use {@link #isRequestedSessionIdFromURL}
*				instead.
*/
public boolean isRequestedSessionIdFromUrl();
}

public class HttpServletRequestWrapper extends ServletRequestWrapper implements HttpServletRequest {

/**
* Constructs a request object wrapping the given request.
* @throws java.lang.IllegalArgumentException if the request is null
*/
public HttpServletRequestWrapper(HttpServletRequest request) {
super(request);
}

private HttpServletRequest _getHttpServletRequest() {
return (HttpServletRequest) super.getRequest();
}

/**
* The default behavior of this method is to return getAuthType()
* on the wrapped request object.
*/

public String getAuthType() {
return this._getHttpServletRequest().getAuthType();
}

/**
* The default behavior of this method is to return getCookies()
* on the wrapped request object.
*/
public Cookie[] getCookies() {
return this._getHttpServletRequest().getCookies();
}

/**
* The default behavior of this method is to return getDateHeader(String name)
* on the wrapped request object.
*/
public long getDateHeader(String name) {
return this._getHttpServletRequest().getDateHeader(name);
}

/**
* The default behavior of this method is to return getHeader(String name)
* on the wrapped request object.
*/
public String getHeader(String name) {
return this._getHttpServletRequest().getHeader(name);
}

/**
* The default behavior of this method is to return getHeaders(String name)
* on the wrapped request object.
*/
public Enumeration getHeaders(String name) {
return this._getHttpServletRequest().getHeaders(name);
}

/**
* The default behavior of this method is to return getHeaderNames()
* on the wrapped request object.
*/

public Enumeration getHeaderNames() {
return this._getHttpServletRequest().getHeaderNames();
}

/**
* The default behavior of this method is to return getIntHeader(String name)
* on the wrapped request object.
*/

public int getIntHeader(String name) {
return this._getHttpServletRequest().getIntHeader(name);
}

/**
* The default behavior of this method is to return getMethod()
* on the wrapped request object.
*/
public String getMethod() {
return this._getHttpServletRequest().getMethod();
}

/**
* The default behavior of this method is to return getPathInfo()
* on the wrapped request object.
*/
public String getPathInfo() {
return this._getHttpServletRequest().getPathInfo();
}

/**
* The default behavior of this method is to return getPathTranslated()
* on the wrapped request object.
*/

public String getPathTranslated() {
return this._getHttpServletRequest().getPathTranslated();
}

/**
* The default behavior of this method is to return getContextPath()
* on the wrapped request object.
*/
public String getContextPath() {
return this._getHttpServletRequest().getContextPath();
}

/**
* The default behavior of this method is to return getQueryString()
* on the wrapped request object.
*/
public String getQueryString() {
return this._getHttpServletRequest().getQueryString();
}

/**
* The default behavior of this method is to return getRemoteUser()
* on the wrapped request object.
*/
public String getRemoteUser() {
return this._getHttpServletRequest().getRemoteUser();
}

/**
* The default behavior of this method is to return isUserInRole(String role)
* on the wrapped request object.
*/
public boolean isUserInRole(String role) {
return this._getHttpServletRequest().isUserInRole(role);
}

/**
* The default behavior of this method is to return getUserPrincipal()
* on the wrapped request object.
*/
public java.security.Principal getUserPrincipal() {
return this._getHttpServletRequest().getUserPrincipal();
}

/**
* The default behavior of this method is to return getRequestedSessionId()
* on the wrapped request object.
*/
public String getRequestedSessionId() {
return this._getHttpServletRequest().getRequestedSessionId();
}

/**
* The default behavior of this method is to return getRequestURI()
* on the wrapped request object.
*/
public String getRequestURI() {
return this._getHttpServletRequest().getRequestURI();
}
/**
* The default behavior of this method is to return getRequestURL()
* on the wrapped request object.
*/
public StringBuffer getRequestURL() {
return this._getHttpServletRequest().getRequestURL();
}

/**
* The default behavior of this method is to return getServletPath()
* on the wrapped request object.
*/
public String getServletPath() {
return this._getHttpServletRequest().getServletPath();
}

/**
* The default behavior of this method is to return getSession(boolean create)
* on the wrapped request object.
*/
public HttpSession getSession(boolean create) {
return this._getHttpServletRequest().getSession(create);
}

/**
* The default behavior of this method is to return getSession()
* on the wrapped request object.
*/
public HttpSession getSession() {
return this._getHttpServletRequest().getSession();
}

/**
* The default behavior of this method is to return isRequestedSessionIdValid()
* on the wrapped request object.
*/

public boolean isRequestedSessionIdValid() {
return this._getHttpServletRequest().isRequestedSessionIdValid();
}

/**
* The default behavior of this method is to return isRequestedSessionIdFromCookie()
* on the wrapped request object.
*/
public boolean isRequestedSessionIdFromCookie() {
return this._getHttpServletRequest().isRequestedSessionIdFromCookie();
}

/**
* The default behavior of this method is to return isRequestedSessionIdFromURL()
* on the wrapped request object.
*/
public boolean isRequestedSessionIdFromURL() {
return this._getHttpServletRequest().isRequestedSessionIdFromURL();
}

/**
* The default behavior of this method is to return isRequestedSessionIdFromUrl()
* on the wrapped request object.
*/
public boolean isRequestedSessionIdFromUrl() {
return this._getHttpServletRequest().isRequestedSessionIdFromUrl();
}

}