import javax.servlet.*;
import javax.servlet.http.*;
servlet的配置
1、导入包:jsp-api.jar,servlet-api.jar
2、把servlet源文件SimpleServlet.java放在WEB-INF\classes路径下
3、修改web.xml配置文件如下
<servlet>
<servlet-name>SimpleServlet</servlet-name>
<servlet-class>com.bn.SimpleServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>SimpleServlet</servlet-name>
<url-pattern>/tttt</url-pattern>
</servlet-mapping>
4、可在浏览器中输入http://localhost:8080/servlet/tttt访问SimpleServlet.java
5、最好把tttt改写成有意义的名字如SimpleServlet.java
如把配置文件改成如下则可以 添加带初始化值:
<servlet>
<servlet-name>SimpleServlet</servlet-name>
<servlet-class>com.bn.SimpleServlet</servlet-class>
<init-param>
<param-name>count</param-name>
<param-value>128</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>SimpleServlet</servlet-name>
<url-pattern>/tttt</url-pattern>
</servlet-mapping>
例:
1、ParamServlet.java//有参数的
package com.bn;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class ParamServlet extends HttpServlet
{
@Override
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,
IOException
{
doPost(request,response);
}
@Override
public void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,
IOException
{
String uname=request.getParameter("uname");
PrintWriter out=response.getWriter();
response.setContentType("text/html");
out.print("Hello,"+uname+", this is the message from servlet");
}
}
2、ToJspServlet.java//跳转到jsp页面
package com.bn;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class ToJspServlet extends HttpServlet
{
@Override
public void doGet(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,
IOException
{
doPost(request,response);
}
@Override
public void doPost(HttpServletRequest request,
HttpServletResponse response)
throws ServletException,
IOException
{
request.getRequestDispatcher("toServlet.jsp").forward(request,response);//页面跳转
}
}
3、 InitServlet.java//配置文件中有默认初始化值时
package com.bn;
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
public class InitServlet extends HttpServlet
{
public void doGet (HttpServletRequest request,HttpServletResponse response) throws IOException
{
String count=this.getInitParameter("count"); //获得默认值
response.getWriter().println("<font size=6 color=red>count: "+count+"</font>");
}
}