servlet跳转
1、跳转类型
客户端跳转：跳转后地址栏改变，无法传递request范围内属性，是在所有的操作都执行完毕之后才发生跳转的操作，跳转语法是，response.sendRedict()
服务器端跳转：地址栏不改变，可以传递request范围内属性，属于无条件跳转，只要执行到了，就立即执行跳转操作，语法是：<jsp:forward></jsp:forward>
2、servlet跳转
2.1 客户端跳转
servlet 中也是可以完成跳转的，servlet本身已经存在HttpServletResponse对象，所有可以直接通过此对象完成sendRedirect跳转操作。
代码如下：
public class ClientRedirectDemo extends HttpServlet {
public void doGet(HttpServletRequest req,HttpServletResponse resp) throws ServletException,IOException{
req.getSession().setAttribute("name","李李") ;
req.setAttribute("info","JAVA") ;
resp.sendRedirect("get_info.jsp") ;
}
public void doPost(HttpServletRequest req,HttpServletResponse resp) throws ServletException,IOException{
this.doGet(req,resp) ;
}
}
xml配置：
<servlet>
<servlet-name>client</servlet-name>
<servlet-class>
com.alice.servletdemo.ClientRedirectDemo
</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>client</servlet-name>
<url-pattern>/forward/ClientRedirectDemo</url-pattern>
</servlet-mapping>
get—info.jsp
<body>
<% request.setCharacterEncoding("GBK") ; %>
<h2>sesion属性：<%=session.getAttribute("name")%></h2>
<h2>request属性：<%=request.getAttribute("info")%></h2>
</body>
2.2 服务器端跳转
代码实现：
public class ServerRedirectDemo extends HttpServlet {
public void doGet(HttpServletRequest req,HttpServletResponse resp) throws ServletException,IOException{
req.getSession().setAttribute("name","李兴华") ;
req.setAttribute("info","MLDNJAVA") ;
RequestDispatcher rd = req.getRequestDispatcher("get_info.jsp") ; // 准备好了跳转操作
rd.forward(req,resp) ; // 完成跳转
}
public void doPost(HttpServletRequest req,HttpServletResponse resp) throws ServletException,IOException{
this.doGet(req,resp) ;
}
}
xml配置：
<servlet>
<servlet-name>server</servlet-name>
<servlet-class>
com.alice.servletdemo.ServerRedirectDemo
</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>server</servlet-name>
<url-pattern>/forward/ServerRedirectDemo</url-pattern>
</servlet-mapping>