每日日报

今日学习代码

package gacl.servlet.study;

import java.io.IOException;
import java.util.Enumeration;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class ServletConfigDemo1 extends HttpServlet {

/**
* 定义ServletConfig对象来接收配置的初始化参数
*/
private ServletConfig config;

/**
* 当servlet配置了初始化参数后，web容器在创建servlet实例对象时，
* 会自动将这些初始化参数封装到ServletConfig对象中，并在调用servlet的init方法时，
* 将ServletConfig对象传递给servlet。进而，程序员通过ServletConfig对象就可以
* 得到当前servlet的初始化参数信息。
*/
@Override
public void init(ServletConfig config) throws ServletException {
this.config = config;
}

public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
//获取在web.xml中配置的初始化参数
String paramVal = this.config.getInitParameter("name");//获取指定的初始化参数
response.getWriter().print(paramVal);

response.getWriter().print("<hr/>");
//获取所有的初始化参数
Enumeration<String> e = config.getInitParameterNames();
while(e.hasMoreElements()){
String name = e.nextElement();
String value = config.getInitParameter(name);
response.getWriter().print(name + "=" + value + "<br/>");
}
}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}

}