javascript当中null和undefined的==和===的比较

1.用init-param获取：

例：1.1.1

servlethello1.java：
package com;
import java.io.ioexception;
import java.io.printwriter;
import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;

public class servlethello1 extends httpservlet {
    protected void doget(httpservletrequest request,httpservletresponse response) throws servletexception, ioexception {
        string salary = getinitparameter("zhangsan");
        system.out.println("salary is "+salary);
    }
}

 

在web.xml中加入：

    <servlet>
        <servlet-name>servlethello1</servlet-name>
        <servlet-class>com.servlethello1</servlet-class>
             <init-param>
                 <param-name>zhangsan</param-name>
                 <param-value>1000</param-value>
             </init-param>
    </servlet>
    <servlet-mapping>
        <servlet-name>servlethello1</servlet-name>

文章转载自原文：