CAS在客户端进行验证

1.原理：

用户在发起登录请求，把自己的用户名和密码传到后台，后台使用httpclient进行模拟登录

登录成功后，CAS服务器会给httpclient发一个cookie（TGT，ticket granting ticket），

服务器会把这个cookie返回给用户，完成一次模拟登录的过程。

2.核心代码：

001	package ecen.mip.sys.action;

002

003	import java.io.BufferedReader;

004	import java.io.IOException;

005	import java.io.InputStreamReader;

006	import java.util.ArrayList;

007	import java.util.List;

008

009	import org.apache.http.HttpEntity;

010	import org.apache.http.HttpResponse;

011	import org.apache.http.NameValuePair;

012	import org.apache.http.client.entity.UrlEncodedFormEntity;

013	import org.apache.http.client.methods.HttpGet;

014	import org.apache.http.client.methods.HttpPost;

015	import org.apache.http.cookie.Cookie;

016	import org.apache.http.impl.client.DefaultHttpClient;

017	import org.apache.http.message.BasicNameValuePair;

018	import org.apache.http.protocol.HTTP;

019	import org.apache.log4j.Logger;

020	import org.apache.struts2.convention.annotation.Action;

021	import org.apache.struts2.convention.annotation.Namespace;

022	import org.apache.struts2.convention.annotation.Result;

023	import org.apache.struts2.convention.annotation.Results;

024	import org.springframework.stereotype.Component;

025

026	@Namespace("/")

027	@Action("sysSingleSignOnAction")

028	@Component("sysSingleSignOnAction")

029	@Results({ @Result(name = "SUCCESS", location = "/sys/sys_new_index.jsp") })

030	public class SysSingleSignOnAction extends BaseAction {

031

032	private static final long serialVersionUID = -2096730223578871319L;

033	private static final Logger log = Logger.getLogger(SysSingleSignOnAction.class);

034	final String server = "http://192.168.0.142:8080/cas/login";

035	private String username;

036	private String password;

037

038

@Override

039	public String execute() throws Exception {

040	Cookie cookie = getTicketGrantingTicket(server, username, password);

041	if(cookie!=null){

042	getResponse().addCookie(convertToServletCookie(cookie));

043	log.info("The user authenticated successfully whose nickname code is "+username+" ! ");

044	return "SUCCESS";

045

}

046	return super.execute();

047

}

048

049

050	private Cookie getTicketGrantingTicket(final String server,final String username, final String password) throws IOException {

051	DefaultHttpClient client = new DefaultHttpClient();

052	HttpPost post = new HttpPost(server);

053

054	List <NameValuePair> nvps = new ArrayList <NameValuePair>();

055	nvps.add(new BasicNameValuePair("username", username));

056	nvps.add(new BasicNameValuePair("password", password));

057	nvps.add(new BasicNameValuePair("lt", doCasLoginRequest(client, server)));

058	nvps.add(new BasicNameValuePair("_eventId", "submit"));

059	post.setEntity(new UrlEncodedFormEntity(nvps, HTTP.UTF_8));

060

try {

061	HttpResponse response = client.execute(post);

062	HttpEntity entity = response.getEntity();

063	if(entity!=null){

064	Cookie cookie = getCookieValue(client, "CASTGC");

065	entity.consumeContent();

066	return cookie;

067

}

068	} catch (Exception e) {

069	e.printStackTrace();

070

}

071	return null;

072

}

073

074

075	private Cookie getCookieValue(DefaultHttpClient httpclient, String name) {

076	List<Cookie> cookies = httpclient.getCookieStore().getCookies();

077	if (cookies.isEmpty()) {

078	return null;

079

} else {

080	for (int i = 0; i < cookies.size(); i++) {

081	Cookie cookie = cookies.get(i);

082	if (cookie.getName().equalsIgnoreCase(name)) {

083	return cookie;

084

}

085

}

086

}

087	return null;

088

}

089

090

091	private String doCasLoginRequest(DefaultHttpClient httpclient, String url) throws IOException {

092	String result = "";

093	HttpGet httpget = new HttpGet(url);

094	HttpResponse response = httpclient.execute(httpget);

095	HttpEntity entity = response.getEntity();

096	BufferedReader rd = new BufferedReader(new InputStreamReader(entity.getContent(), "UTF-8"));

097	String tempLine = rd.readLine();

098	String s = "<input type=\"hidden\" name=\"lt\" value=\"";

099	while (tempLine != null){

100	int index = tempLine.indexOf(s);

101	if(index != -1) {

102	String s1 = tempLine.substring(index + s.length());

103	int index1 = s1.indexOf("\"");

104	if(index1 != -1)

105	result = s1.substring(0, index1);

106

}

107	tempLine = rd.readLine();

108

}

109	if (entity != null) {

110	entity.consumeContent();

111

}

112	return result;

113

}

114

115

116	private javax.servlet.http.Cookie convertToServletCookie(Cookie cookie){

117	javax.servlet.http.Cookie retCookie = new javax.servlet.http.Cookie(cookie.getName(), cookie.getValue());

118	retCookie.setComment(cookie.getComment());

119	retCookie.setDomain(cookie.getDomain());

120	retCookie.setHttpOnly(false);

121	retCookie.setSecure(false);

122	retCookie.setPath(cookie.getPath());

123	retCookie.setVersion(cookie.getVersion());

124	retCookie.setMaxAge((int) ((cookie.getExpiryDate().getTime()-System.currentTimeMillis())/1000));

125	return retCookie;

126

}

127

128	public String getUsername() {

129	return username;

130

}

131

132	public void setUsername(String username) {

133	this.username = username;

134

}

135

136	public String getPassword() {

137	return password;

138

}

139

140	public void setPassword(String password) {

141	this.password = password;

142

}

143

144

}

 

 

写完就贴上来了，所以没写注释，不过，应该都能看懂吧

3.注意事项：

通过这种途径登录后，request.getRemoteUser()不能使用，具体原因还不知道。