可用分押宝游戏火热进行中...	专题改版：Java Web 专题

request对象有哪些方法？

楼主xiakebuxing（侠客不行）2004-08-04 10:57:13 在 Java / Web 开发提问

如题，提供电子书的满分. 问题点数：100、回复次数：11Top

1 楼790228（自古华山一条道）回复于 2004-08-04 11:32:05 得分 10

你留下E-MAILTop

2 楼liujiansxcd（黑客精神）回复于 2004-08-04 11:38:03 得分 10

兄弟，你装tomcat了吗？tomcat/webapps/tomcat-docs下面有servlet的API，你所要的东西那里面都会有，不只是request，其他的变量也都有！Top

3 楼lovelymaomao（小老鼠）回复于 2004-08-04 11:42:01 得分 0

他啊。。你没有javadoc嘛？Top

4 楼liujiansxcd（黑客精神）回复于 2004-08-04 11:45:24 得分 10

javadoc里面没有servlet和jsp的文档，要专门去下，或者一些服务器自带这些文档！Top

5 楼xiakebuxing（侠客不行）回复于 2004-08-19 15:58:21 得分 0

up，我有许多问题没有人答。散分！
Top

6 楼yihan422（穿22号球衣的）回复于 2004-08-19 16:08:48 得分 20

Field Summary
static java.lang.String BASIC_AUTH
String identifier for Basic authentication.
static java.lang.String CLIENT_CERT_AUTH
String identifier for Client Certificate authentication.
static java.lang.String DIGEST_AUTH
String identifier for Digest authentication.
static java.lang.String FORM_AUTH
String identifier for Form authentication.
Method Summary
java.lang.String getAuthType()
Returns the name of the authentication scheme used to protect the servlet.
java.lang.String getContextPath()
Returns the portion of the request URI that indicates the context of the request.
Cookie[] getCookies()
Returns an array containing all of the Cookie objects the client sent with this request.
long getDateHeader(java.lang.String name)
Returns the value of the specified request header as a long value that represents a Date object.
java.lang.String getHeader(java.lang.String name)
Returns the value of the specified request header as a String.
java.util.Enumeration getHeaderNames()
Returns an enumeration of all the header names this request contains.
java.util.Enumeration getHeaders(java.lang.String name)
Returns all the values of the specified request header as an Enumeration of String objects.
int getIntHeader(java.lang.String name)
Returns the value of the specified request header as an int.
java.lang.String getMethod()
Returns the name of the HTTP method with which this request was made, for example, GET, POST, or PUT.
java.lang.String getPathInfo()
Returns any extra path information associated with the URL the client sent when it made this request.
java.lang.String getPathTranslated()
Returns any extra path information after the servlet name but before the query string, and translates it to a real path.
java.lang.String getQueryString()
Returns the query string that is contained in the request URL after the path.
java.lang.String getRemoteUser()
Returns the login of the user making this request, if the user has been authenticated, or null if the user has not been authenticated.
java.lang.String getRequestedSessionId()
Returns the session ID specified by the client.
java.lang.String getRequestURI()
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.
java.lang.StringBuffer getRequestURL()
Reconstructs the URL the client used to make the request.
java.lang.String getServletPath()
Returns the part of this request's URL that calls the servlet.
HttpSession getSession()
Returns the current session associated with this request, or if the request does not have a session, creates one.
HttpSession getSession(boolean create)
Returns the current HttpSession associated with this request or, if there is no current session and create is true, returns a new session.
java.security.Principal getUserPrincipal()
Returns a java.security.Principal object containing the name of the current authenticated user.
boolean isRequestedSessionIdFromCookie()
Checks whether the requested session ID came in as a cookie.
boolean isRequestedSessionIdFromUrl()
Deprecated. As of Version 2.1 of the Java Servlet API, use isRequestedSessionIdFromURL() instead.
boolean isRequestedSessionIdFromURL()
Checks whether the requested session ID came in as part of the request URL.
boolean isRequestedSessionIdValid()
Checks whether the requested session ID is still valid.
boolean isUserInRole(java.lang.String role)
Returns a boolean indicating whether the authenticated user is included in the specified logical "role".
Top

7 楼yihan422（穿22号球衣的）回复于 2004-08-19 16:10:20 得分 10

Method Detail

getAuthType
public java.lang.String getAuthType()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 null is returned.
Same as the value of the CGI variable AUTH_TYPE.

Returns:
one of the static members BASIC_AUTH, FORM_AUTH, CLIENT_CERT_AUTH, DIGEST_AUTH (suitable for == comparison) or the container-specific string indicating the authentication scheme, or null if the request was not authenticated.

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getCookies
public Cookie[] getCookies()Returns an array containing all of the Cookie objects the client sent with this request. This method returns null if no cookies were sent.

Returns:
an array of all the Cookies included with this request, or null if the request has no cookies

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getDateHeader
public long getDateHeader(java.lang.String name)Returns the value of the specified request header as a long value that represents a Date object. Use this method with headers that contain dates, such as If-Modified-Since.
The date is returned as the number of milliseconds since January 1, 1970 GMT. The header name is case insensitive.

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 IllegalArgumentException.

Parameters:
name - a String specifying the name of the header
Returns:
a long value representing 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 request
Throws:
java.lang.IllegalArgumentException - If the header value can't be converted to a date

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getHeader
public java.lang.String getHeader(java.lang.String name)Returns the value of the specified request header as a String. If the request did not include a header of the specified name, this method returns null. 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.

Parameters:
name - a String specifying the header name
Returns:
a String containing the value of the requested header, or null if the request does not have a header of that name

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getHeaders
public java.util.Enumeration getHeaders(java.lang.String name)Returns all the values of the specified request header as an Enumeration of String objects.
Some headers, such as Accept-Language can be sent by clients as several headers each with a different value rather than sending the header as a comma separated list.

If the request did not include any headers of the specified name, this method returns an empty Enumeration. The header name is case insensitive. You can use this method with any request header.

Parameters:
name - a String specifying the header name
Returns:
an Enumeration 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

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getHeaderNames
public java.util.Enumeration getHeaderNames()Returns an enumeration of all the header names this request contains. If the request has no headers, this method returns an empty enumeration.
Some servlet containers do not allow servlets to access headers using this method, in which case this method returns null

Returns:
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, null

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getIntHeader
public int getIntHeader(java.lang.String name)Returns the value of the specified request header as an int. 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 NumberFormatException.
The header name is case insensitive.

Parameters:
name - a String specifying the name of a request header
Returns:
an integer expressing the value of the request header or -1 if the request doesn't have a header of this name
Throws:
java.lang.NumberFormatException - If the header value can't be converted to an int

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getMethod
public java.lang.String getMethod()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.

Returns:
a String specifying the name of the method with which this request was made

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getPathInfo
public java.lang.String getPathInfo()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.
This method returns null if there was no extra path information.

Same as the value of the CGI variable PATH_INFO.

Returns:
a String, 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 null if the URL does not have any extra path information

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getPathTranslated
public java.lang.String getPathTranslated()Returns any extra path information after the servlet name but before the query string, and translates it to a real path. Same as the value of the CGI variable PATH_TRANSLATED.
If the URL does not have any extra path information, this method returns null 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.

Returns:
a String specifying the real path, or null if the URL does not have any extra path information
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8 楼yyqllxh2004（潇一郎）回复于 2004-08-19 16:10:25 得分 10

<%@ page import="java.io.*"%>
Request Object Info:
<hr>
<%
out.println(" getMethod:");
out.println(request.getMethod());
out.println(" getParameter:");
out.println(request.getParameter("name"));

out.println(" getAttributeNames:");
java.util.Enumeration e=request.getAttributeNames();
while(e.hasMoreElements())
out.println(e.nextElement());

out.println(" getCharacterEncoding:");
out.println(request.getCharacterEncoding());
out.println(" getContentLength: ");
out.println(request.getContentLength());
out.println(" getContentType:");
out.println(request.getContentType());
out.println(" getLocale:");
out.println(request.getLocale());
out.println(" getProtocol:");
out.println(request.getProtocol());
out.println(" getRemoteAddr:");
out.println(request.getRemoteAddr());
out.println(" getRemoteHost:");
out.println(request.getRemoteHost());
out.println(" getRemoteUser:");
out.println(request.getRemoteUser());
out.println(" getServerName:");
out.println(request.getServerName());
out.println(" getServerPort:");
out.println(request.getServerPort());
out.println(" getSession:");
out.println(request.getSession(true));
out.println(" getHeader('User-Agent')");
out.println( request.getHeader("User-Agent"));
%>

不过以后这个问题最好不要问，电子图书网上多的是Top

9 楼yihan422（穿22号球衣的）回复于 2004-08-19 16:10:37 得分 10

getContextPath
public java.lang.String getContextPath()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.

Returns:
a String specifying the portion of the request URI that indicates the context of the request

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getQueryString
public java.lang.String getQueryString()Returns the query string that is contained in the request URL after the path. This method returns null if the URL does not have a query string. Same as the value of the CGI variable QUERY_STRING.

Returns:
a String containing the query string or null if the URL contains no query string. The value is not decoded by the container.

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getRemoteUser
public java.lang.String getRemoteUser()Returns the login of the user making this request, if the user has been authenticated, or null 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.

Returns:
a String specifying the login of the user making this request, or null if the user login is not known

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isUserInRole
public boolean isUserInRole(java.lang.String role)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 false.

Parameters:
role - a String specifying the name of the role
Returns:
a boolean indicating whether the user making this request belongs to a given role; false if the user has not been authenticated

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getUserPrincipal
public java.security.Principal getUserPrincipal()Returns a java.security.Principal object containing the name of the current authenticated user. If the user has not been authenticated, the method returns null.

Returns:
a java.security.Principal containing the name of the user making this request; null if the user has not been authenticated

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getRequestedSessionId
public java.lang.String getRequestedSessionId()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 null.

Returns:
a String specifying the session ID, or null if the request did not specify a session ID
See Also:
isRequestedSessionIdValid()

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getRequestURI
public java.lang.String getRequestURI()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: First line of HTTP request Returned Value
POST /some/path.html HTTP/1.1 /some/path.html
GET http://foo.bar/a.html HTTP/1.0 /a.html
HEAD /xyz?a=b HTTP/1.1 /xyz

To reconstruct an URL with a scheme and host, use HttpUtils.getRequestURL(javax.servlet.http.HttpServletRequest).

Returns:
a String containing the part of the URL from the protocol name up to the query string
See Also:
HttpUtils.getRequestURL(javax.servlet.http.HttpServletRequest)

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getRequestURL
public java.lang.StringBuffer getRequestURL()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.
Because this method returns a StringBuffer, not a string, you can modify the URL easily, for example, to append query parameters.

This method is useful for creating redirect messages and for reporting errors.

Returns:
a StringBuffer object containing the reconstructed URL

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getServletPath
public java.lang.String getServletPath()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.
This method will return an empty string ("") if the servlet used to process this request was matched using the "/*" pattern.

Returns:
a String 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.

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getSession
public HttpSession getSession(boolean create)Returns the current HttpSession associated with this request or, if there is no current session and create is true, returns a new session.
If create is false and the request has no valid HttpSession, this method returns null.

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.

Parameters:
create - true to create a new session for this request if necessary; false to return null if there's no current session
Returns:
the HttpSession associated with this request or null if create is false and the request has no valid session
See Also:
getSession()

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getSession
public HttpSession getSession()Returns the current session associated with this request, or if the request does not have a session, creates one.

Returns:
the HttpSession associated with this request
See Also:
getSession(boolean)

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isRequestedSessionIdValid
public boolean isRequestedSessionIdValid()Checks whether the requested session ID is still valid.

Returns:
true if this request has an id for a valid session in the current session context; false otherwise
See Also:
getRequestedSessionId(), getSession(boolean), HttpSessionContext

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isRequestedSessionIdFromCookie
public boolean isRequestedSessionIdFromCookie()Checks whether the requested session ID came in as a cookie.

Returns:
true if the session ID came in as a cookie; otherwise, false
See Also:
getSession(boolean)

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isRequestedSessionIdFromURL
public boolean isRequestedSessionIdFromURL()Checks whether the requested session ID came in as part of the request URL.

Returns:
true if the session ID came in as part of a URL; otherwise, false
See Also:
getSession(boolean)

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isRequestedSessionIdFromUrl
public boolean isRequestedSessionIdFromUrl()Deprecated. As of Version 2.1 of the Java Servlet API, use isRequestedSessionIdFromURL() instead.Top

10 楼edhappy（咕咕鸟）回复于 2004-08-19 18:18:47 得分 10

看看api不就可以了。Top

11 楼lbh16888（）回复于 2004-08-19 22:11:17 得分 10

yihan422(穿22号球衣的) 哈哈，我喜欢你的方式，我平常不知道函数的用法的时候，我就会去看类文件的注解，呵呵。感觉那是最好的回答了！Top