import javax.servlet.Filter;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.FilterChain;
import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpServletResponse;
public class RightFilter
implements Filter {
public void init(FilterConfig filterConfig) throws ServletException {
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
HttpServletResponse res = (HttpServletResponse) response;
HttpSession session = req.getSession(true);
//从session里取的用户名信息
String username = (String) session.getAttribute("username");
//判断如果没有取到用户信息,就跳转到登陆页面
if (username == null || "".equals(username)) {
//跳转到登陆页面
res.sendRedirect("http://" req.getHeader("Host") "/login.jsp");
}
else {
//已经登陆,继续此次请求
chain.doFilter(request,response);
}
}
public void destroy() {
}
}
然后在web.xml里配置那些JSP文件需要登陆权限验证:
1.如果是某个具体的JSP文件(如a.jsp)需要登陆验证
<web-app>
...
<filter>
<filter-name>right</filter-name>
<filter-class>com.taihuatalk.taihua.common.common.RightFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>right</filter-name>
<url-pattern>/a.jsp</url-pattern>
</filter-mapping>
...
</web-app>
2.如果是某一个目录(如a/目录)整个目录下的文件都需要登陆验证:
<web-app>
...
<filter>
<filter-name>right</filter-name>
<filter-class>com.taihuatalk.taihua.common.common.RightFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>right</filter-name>
<url-pattern>/a/*</url-pattern>
</filter-mapping>
...
</web-app>import javax.servlet.Filter;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.FilterChain;
import java.io.IOException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
import javax.servlet.http.HttpServletResponse;
public class RightFilter
implements Filter {
public void init(FilterConfig filterConfig) throws ServletException {
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
HttpServletResponse res = (HttpServletResponse) response;
HttpSession session = req.getSession(true);
//从session里取的用户名信息
String username = (String) session.getAttribute("username");
//判断如果没有取到用户信息,就跳转到登陆页面
if (username == null || "".equals(username)) {
//跳转到登陆页面
res.sendRedirect("http://" req.getHeader("Host") "/login.jsp");
}
else {
//已经登陆,继续此次请求
chain.doFilter(request,response);
}
}
public void destroy() {
}
}
然后在web.xml里配置那些JSP文件需要登陆权限验证:
1.如果是某个具体的JSP文件(如a.jsp)需要登陆验证
<web-app>
...
<filter>
<filter-name>right</filter-name>
<filter-class>com.taihuatalk.taihua.common.common.RightFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>right</filter-name>
<url-pattern>/a.jsp</url-pattern>
</filter-mapping>
...
</web-app>
2.如果是某一个目录(如a/目录)整个目录下的文件都需要登陆验证:
<web-app>
...
<filter>
<filter-name>right</filter-name>
<filter-class>com.taihuatalk.taihua.common.common.RightFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>right</filter-name>
<url-pattern>/a/*</url-pattern>
</filter-mapping>
...
</web-app>
==========================
字符集定义，多用与中文问题。
public class CharSetFilter implements javax.servlet.Filter {
protected String encoding = null;
protected FilterConfig filterConfig = null;
protected boolean ignore = true;
/**
* Take this filter out of service.
*/
public void destroy() {
this.encoding = null;
this.filterConfig = null;
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain)
throws IOException, ServletException {
if (ignore || (request.getCharacterEncoding() == null)) {
String encoding = selectEncoding(request);
if (encoding != null)
request.setCharacterEncoding(encoding);
}
// Pass control on to the next filter
chain.doFilter(request, response);
}
/**
* Place this filter into service.
*
* @param filterConfig The filter configuration object
*/
public void init(FilterConfig filterConfig) throws ServletException {
this.filterConfig = filterConfig;
this.encoding = filterConfig.getInitParameter("encoding");//取web.xml中配的参数
String value = filterConfig.getInitParameter("ignore");
if (value == null)
this.ignore = true;
else if (value.equalsIgnoreCase("true"))
this.ignore = true;
else if (value.equalsIgnoreCase("yes"))
this.ignore = true;
else
this.ignore = false;
}
protected String selectEncoding(ServletRequest request) {
return (this.encoding);
}
}
web.xml中的配置:
<filter>
<filter-name>SetEncoding</filter-name>
<filter-class>com.xxxx.filter.CharSetFilter</filter-class>
<init-param>
<param-name>encoding</param-name><!-- 指定编码 -->
<param-value>GB2312</param-value>
</init-param>
</filter>
<filter-mapping>
<filter-name>SetEncoding</filter-name>
<url-pattern>/*</url-pattern>//对所有的请求都指定字符集
</filter-mapping>
权限控制(只判断session有没有值，可以扩展到更复杂)
public class CheckSessionFilter implements Filter {
protected FilterConfig filterConfig = null;
protected boolean checkit = true;
protected String user_key="user_id";
protected String sessionerror="/error.jsp";
protected String sessionerror2="";
protected String special=null;
/**
* destroy
*
* @todo Implement this javax.servlet.Filter method
*/
public void destroy() {
this.filterConfig =null;
this.checkit =true;
this.user_key ="user_id";
this.sessionerror ="/error.jsp";
this.sessionerror2 ="";
this.special =null;
}
/**
* doFilter
*
* @param servletRequest ServletRequest
* @param servletResponse ServletResponse
* @param filterChain FilterChain
* @throws IOException
* @throws ServletException
* @todo Implement this javax.servlet.Filter method
*/
public void doFilter(ServletRequest servletRequest,
ServletResponse servletResponse,
FilterChain filterChain) throws IOException,
ServletException {
if(servletRequest instanceof HttpServletRequest){
HttpServletRequest servlets = (HttpServletRequest) servletRequest;
HttpSession session=servlets.getSession();
Object user=session.getAttribute(this.user_key );
//System.out.println(user);
boolean find=false;
int types=1;
if(this.special !=null){
String[] temp=TheStrings.split(special,",");
String paths=servlets.getServletPath() ;
if(paths.indexOf("league")>=0){
types=2;
}
if(temp.length >=0){
for(int i=0;i<temp.length ;i++){
if(paths.indexOf(temp[i])>=0) {
find=true;
break;
}
}
}
//String address=servlets.getr
}
if(!find&&(user==null||user.toString() .trim() .length() ==0)){
if(types==2){
servletRequest.getRequestDispatcher(this.sessionerror2).forward(servletRequest,servletResponse);
}
else{
servletRequest.getRequestDispatcher(this.sessionerror).forward(servletRequest,servletResponse);
}
}else{
filterChain.doFilter(servletRequest,servletResponse);
}
}else{
filterChain.doFilter(servletRequest,servletResponse);
}
}
/**
* init
*
* @param filterConfig FilterConfig
* @throws ServletException
* @todo Implement this javax.servlet.Filter method
*/
public void init(FilterConfig filterConfig2) throws ServletException {
this.filterConfig = filterConfig2;
String check=filterConfig.getInitParameter("checkit");
String user_keys=filterConfig.getInitParameter("user_key");
String sessionerrors=filterConfig.getInitParameter("errorPath");
String sessionerrors2=filterConfig.getInitParameter("errorPath_league");
String specials=filterConfig.getInitParameter("special");
if(check==null) this.checkit =true;
else if(check.equals("true")) this.checkit =true;
else this.checkit =false;
if(user_keys!=null&&user_keys.trim().length() >0) this.user_key =user_keys;
if(sessionerrors!=null&&sessionerrors.trim().length() >0) this.sessionerror =sessionerrors;
if(sessionerrors2!=null&&sessionerrors2.trim().length() >0) this.sessionerror2 =sessionerrors2;
if(specials!=null&&specials.trim().length() >0) this.special=specials;
}
}
对应web.xml配置:
<filter>
<filter-name>checkSession</filter-name>
<filter-class>com.xxxx.filter.CheckSessionFilter</filter-class>
<init-param>
<param-name>checkit</param-name><!-- 是否检查权限 -->
<param-value>true</param-value>
</init-param>
<init-param>
<param-name>user_key</param-name><!-- session中的关键key -->
<param-value>username</param-value>
</init-param>
<init-param>
<param-name>errorPath</param-name>
<param-value>/error/sessionTimeout.jsp</param-value><!-- 错误页面（后台） -->
</init-param>
<init-param>
<param-name>errorPath_league</param-name>
<param-value>/error/sessionTimeout2.jsp</param-value><!-- 错误页面（前台）-->
</init-param>
<init-param>
<param-name>special</param-name>
<param-value>redirect.jsp,login.jsp,add</param-value><!-- 不需要权限控制的资源列表 -->
</init-param>
</filter>
<filter-mapping>
<filter-name>checkSession</filter-name>
<url-pattern>/*.jsp</url-pattern><!-- filter的作用域 -->
</filter-mapping>