过滤器实现登录
过滤器实现登录（源码待上传）
1.项目思路分析：
首先创建一个项目---->login.jsp,sucess.jsp,fail.jsp---->login.jsp提交用户名和密码到LoginServlet.java-
处理业务逻辑--->在web.xml建立过滤器--->
2.代码分析
login.jsp
<body>
<form action="<%=request.getContextPath() %>/servlet/LoginServlet" method="post">
用户名:<input type="text" name="username">
密码:<input type="password" name="password">
<input type="submit" value="提交">
</form>
</body>
web.xml
<filter>
<filter-name>LoginFilter</filter-name>
<filter-class>com.imooc.LoginFilter.LoginFilter</filter-class>
</filter>
<filter-mapping>
<filter-name>LoginFilter</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>
fail.jsp
<body>
登录失败
</body>
sucess.jsp
<body>
登录成功${name }
</body>
LoginServlet.jsva
public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
String username = request.getParameter("username");
String password = request.getParameter("password");
System.out.println(username);
if("admin".equals(username) && "admin".equals(password)){
HttpSession session = request.getSession();
session.setAttribute("username", username);
response.sendRedirect(request.getContextPath()+"/sucess.jsp");
}else{
response.sendRedirect(request.getContextPath()+"/fail.jsp");
}
}
LoginFilter.java
public class LoginFilter implements Filter {
private FilterConfig config;
@Override
public void destroy() {
}
@Override
public void doFilter(ServletRequest arg0, ServletResponse arg1, FilterChain arg2) throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) arg0;
HttpServletResponse response = (HttpServletResponse) arg1;
HttpSession session = request.getSession();
String noLoginPaths = config.getInitParameter("noLoginPaths");
String charset = config.getInitParameter("charset");
if(charset==null){
charset = "UTF-8";
}
request.setCharacterEncoding(charset);
if(noLoginPaths!=null){
String[] strArray = noLoginPaths.split(";");
for (int i = 0; i < strArray.length; i++) {
if(strArray[i]==null || "".equals(strArray[i]))continue;
if(request.getRequestURI().indexOf(strArray[i])!=-1 ){
arg2.doFilter(arg0, arg1);
return;
}
}
}
if(session.getAttribute("username")!=null){
arg2.doFilter(arg0, arg1);
}else{
response.sendRedirect("login.jsp");
}
}
@Override
public void init(FilterConfig arg0) throws ServletException {
config = arg0;
}
}
