js脚本中执行java后台代码方法解析

使用场景：关闭页面弹窗时执行sql语句。其实js里执行sql语句有多种方式。方式一：直接在j

使用场景：关闭页面弹窗时执行sql语句。

其实js里执行sql语句有多种方式。

方式一：直接在js代码里调用sql语句，原则上不能使用，因为这将sql直接暴露在客户端，安全性极差。

方式二：在js里运用ajax技术，调用后台方法执行sql语句。

方式三：运用dwr框架，其实是对ajax技术进行了封装。

一、首先编写一个dwr.xml文件

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE dwr PUBLIC "-//GetAhead Limited//DTD Direct Web Remoting 2.0//EN" "http://www.getahead.ltd.uk/dwr//dwr20.dtd">
<dwr>
 <allow>
 <!-- 对呼叫类型的操作 -->
 <create javascript="CallTypeOpDwr" creator="new">
 <param name="class"
 value="cn.etcom.jfgl.tel.fee.callType.CallTypeOpDwr" />
 <include method="addCallType" />
 <include method="modifyCallType" />
 <include method="deleteCallType" />
 <include method="updateSp" />
 </create>

 </allow>
 <!-- 用户信息管理操作中用到的map配置 -->
 <signatures>
 <![CDATA[ 
 import java.util.List; 
 import cn.etcom.jfgl.customer.tel.userInfo.UserInfoManageOpDwr;
 UserInfoManageOpDwr.addUsersInfo(String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,Map<String,String>); 
 UserInfoManageOpDwr.addUserInfo(String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,String,Map<String,String>); 
 ]]>
 </signatures>
</dwr>

二、在web.xml文件里配置servlet

<!-- DWR相关配置 -->
 <servlet>
 <servlet-name>dwr-invoker</servlet-name>
 <servlet-class>uk.ltd.getahead.dwr.DWRServlet</servlet-class>
 <init-param>
 <param-name>debug</param-name>
 <param-value>false</param-value>
 </init-param>
 <init-param>
 <param-name>
 allowGetForSafariButMakeForgeryEasier
 </param-name>
 <param-value>true</param-value>
 </init-param>
 <init-param> 
 <param-name>crossDomainSessionSecurity</param-name> 
 <param-value>false</param-value> 
 </init-param>
 <load-on-startup>1</load-on-startup>
 </servlet>
 <servlet-mapping>
 <servlet-name>dwr-invoker</servlet-name>
 <url-pattern>/dwr/*</url-pattern>
 </servlet-mapping>

三、写一个普通的JAVA类

package cn.etcom.jfgl.tel.fee.callType;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.json.JSONException;
import org.json.JSONObject;

import cn.etcom.common.utility.DBUtil;
import cn.etcom.common.utility.RsHandler;
import cn.etcom.common.utility.SqlActuator;
import cn.etcom.common.utility.StringUtil;

/*******************************************************************************
 * 
 * @author 刘彦宁 2011-08-12
 * 
 */
// 处理呼叫类型的dwr
public class CallTypeOpDwr {
 
 /***************************************************************************
 * DWR 方法，执行存储过程。
 * 
 */
 public String updateSp() {
 String sql = "exec Pub_Sp_UpdateFieldMemo ?";
 Connection conn = DBUtil.getConnection();
 PreparedStatement psmt = null;
 try {
 psmt = conn.prepareStatement(sql);
 psmt.setString(1, "CALL");
 boolean a = psmt.execute();
 DBUtil.close(null, psmt, conn);
 conn = DBUtil.getConnection();
 psmt = conn.prepareStatement(sql);
 psmt.setString(1, "USER");
 boolean b = psmt.execute();
 System.out.println(a);
 System.out.println(b);
 System.out.println("关闭弹窗执行存储过程 >> "+sql);
 } catch (SQLException e) {
 e.printStackTrace();
 }finally {
 DBUtil.close(null, psmt, conn);
 }
 return null;
 }
}

四、写一个JSP页面，主要导入engine.js和相应的java类映射的js文件，然后编写js即可调用

//以下为jsp的引入js文件部分
<script type="text/javascript">
 //设置根路径，放在 tab.js 前
 var glbRootPath = "<%=basePath%>";
</script>
<script src="<%=basePath%>js/lhgdialog/lhgcore.min.js" type="text/javascript"></script>
<script src="<%=basePath%>js/lhgdialog/lhgdialog.js" type="text/javascript"></script>

五、js文件里调用后台代码

var basePath = "";
 if(typeof(glbRootPath) != "undefined"){ 
 basePath = glbRootPath;
 document.write("<script type='text/javascript' src='"+basePath+"\/dwr\/engine.js'><\/script><script type='text/javascript' src='"+basePath+"\/dwr\/interface\/CallTypeOpDwr.js'><\/script>");
 }
/*
中间省略若干代码
*/
.
.
.
if(typeof(glbRootPath) != "undefined"&&$(this).parent().children().eq(0).text()=="呼叫类型设置"){
 console.log("进来了");
 DWREngine.setAsync(false);
 CallTypeOpDwr.updateSp();
 }

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。