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();
    }
 
}