js腳本中執行java后台代碼

使用場景：關閉頁面彈窗時執行sql語句。

其實js里執行sql語句有多種方式。

方式一：直接在js代碼里調用sql語句，原則上不能使用，因為這將sql直接暴露在客戶端，安全性極差。

方式二：在js里運用ajax技術，調用后台方法執行sql語句。

方式三：運用dwr框架，其實是對ajax技術進行了封裝。

一、首先編寫一個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>
        <!-- 對呼叫類型的操作 -->
        <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>
    <!-- 用戶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相關配置 -->
    <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、寫一個普通的JAVA類

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 劉彥寧 2011-08-12
 * 
 */
// 處理呼叫類型的dwr
public class CallTypeOpDwr {
    
    /***************************************************************************
     * DWR 方法，執行存儲過程。
     * 
     */
    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("關閉彈窗執行存儲過程 >> "+sql);
        } catch (SQLException e) {
            e.printStackTrace();
        }finally {
            DBUtil.close(null, psmt, conn);
        }
        return null;
    }
}

四、寫一個JSP頁面，主要導入engine.js和相應的java類映射的js文件，然后編寫js即可調用。

//以下為jsp的引入js文件部分
<script type="text/javascript">
    //設置根路徑，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文件里調用后台代碼

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>");
    }
/*
中間省略若干代碼
*/
.
.
.
if(typeof(glbRootPath) != "undefined"&&$(this).parent().children().eq(0).text()=="呼叫類型設置"){
                console.log("進來了");
                DWREngine.setAsync(false);
                CallTypeOpDwr.updateSp();
            }