Ajax实现jsp里面某个输入框内容修改之后后台数据库自动更新
对应在数据库中表格 rocars表的msg_id,ccrn两个字段。现在要实现在界面上修改ccrn的值，ajax提交到response.jsp页面，并调用RocarsEntiy.updateCcrn方法更新对应的ccrn，最后无刷新显示。
request.jsp页面中有rocarsId,和ccrn两个text。
对应在数据库中表格 rocars表的msg_id,ccrn两个字段。现在要实现在界面上修改ccrn的值，ajax提交到response.jsp页面，并调用RocarsEntiy.updateCcrn方法更新对应的ccrn，最后无刷新显示
代码：
request.jsp:
<%@ page language="java" contentType="text/html; charset=ISO-8859-1" pageEncoding="ISO-8859-1"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> <script language="javascript"><!-- function GetXmlHttpObject(){ var xmlHttp = null; try{ xmlHttp = new XMLHttpRequest(); }catch(e){ try{ xmlHttp = new ActiveXObject("Msxml2.XMLHTTP"); }catch(e){ xmlHttp = new ActiveXObject("Microsoft.XMLHTTP"); } } return xmlHttp; } function updateCcrn(rocarsId,ccrn){ alert(rocarsId) alert(ccrn) xmlHttp = GetXmlHttpObject(); if(xmlHttp == null){ alert ("you browser don't support the ajax"); return; } var url = "./response.jsp"; url = url + "?rocarsId="+ rocarsId; url = url + "&ccrn="+ ccrn; url = url + "&sid ="+ Math.random(); xmlHttp.onreadystatechange = stateChanged; xmlHttp.open("GET", url, true); xmlHttp.send(null); } function getCcrn(str){ xmlHttp = GetXmlHttpObject(); if(xmlHttp == null){ alert ("you browser don't support the ajax"); return; } var url = "./response.jsp"; url = url + "?q="+ str; url = url + "&sid ="+ Math.random(); xmlHttp.onreadystatechange = stateChanged; xmlHttp.open("GET", url, true); xmlHttp.send(null); } function stateChanged() { if(xmlHttp.readyState==4) { document.getElementById("rocarsccrn").value = xmlHttp.responseText; } } // --></script> </head> <body> <form name="form1" action="" method="post"> <label>rocarsId:</label><input type="text" name="rocarsId" value="140" /> <label>ccrn:</label><input type="text" id="rocarsccrn" name="rocarsccrn" onchange="updateCcrn(document.form1.rocarsId.value,this.value)"/> </form> </body> </html><%@ page language="java" contentType="text/plain; charset=UTF-8" pageEncoding="UTF-8"%> <%@ page import="com.lwf.eus.util.*,java.util.*,com.lwf.eus.entity.*,com.lwf.eus.bean.*" %> <% String rocarsId = request.getParameter("rocarsId"); String ccrn = request.getParameter("ccrn"); System.out.println("rocarsId:" + rocarsId); System.out.println("ccrn:" + ccrn); RocarsEntity.updateCcrnById(rocarsId,ccrn); out.print(ccrn); %>package com.lwf.eus.entity;import java.sql.Connection;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import java.util.Vector;import com.lwf.eus.bean.RocarsBean;import com.lwf.eus.util.ConnectionManager;public class RocarsEntity {public static Vector getRocarsList() {Vector vRocars = new Vector();// Connection conn = ConnectionManager.getConnection();Connection conn = ConnectionManager.getConnectionFromDS();Statement st = ConnectionManager.createStatement(conn);String sql = "select msg_id,ccrn from rocars";ResultSet rs = null;try {rs = st.executeQuery(sql);while (rs.next()) {RocarsBean rocars = new RocarsBean();rocars.setRocarsId(rs.getString(1));rocars.setCcrn(rs.getString(2));vRocars.addElement(rocars);}} catch (SQLException e) {e.printStackTrace();} finally {try {if (rs != null) {rs.close();}} catch (SQLException e) {e.printStackTrace();}try {if (st != null) {st.close();}} catch (SQLException e) {e.printStackTrace();}try {if (conn != null) {conn.close();}} catch (SQLException e) {e.printStackTrace();}return vRocars;}}public static RocarsBean getRocarsListById(String rocarsId) {Connection conn = ConnectionManager.getConnectionFromDS();Statement st = ConnectionManager.createStatement(conn);String sql = "select * from rocars where msg_id=" + rocarsId;ResultSet rs = null;RocarsBean rocars = null;try {rs = st.executeQuery(sql);rocars = new RocarsBean();while (rs.next()) {rocars.setRocarsId(rs.getString("msg_id"));rocars.setCcrn(rs.getString("ccrn"));}} catch (SQLException e) {e.printStackTrace();} finally {try {if (rs != null) {rs.close();}} catch (SQLException e) {e.printStackTrace();}try {if (st != null) {st.close();}} catch (SQLException e) {e.printStackTrace();}try {if (conn != null) {conn.close();}} catch (SQLException e) {e.printStackTrace();}return rocars;}}public static void updateCcrnById(String rocarsId, String ccrn) {Connection conn = null;Statement stmt = null;try {conn = ConnectionManager.getConnectionFromDS();stmt = ConnectionManager.createStatement(conn);String sqlStr = "update rocars set ccrn= '" + ccrn + "'"+ "where msg_id=" + rocarsId;stmt.executeUpdate(sqlStr);} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();} finally {try {if (stmt != null) {stmt.close();}} catch (SQLException e) {e.printStackTrace();}try {if (conn != null) {conn.close();}} catch (SQLException e) {e.printStackTrace();}}}}package com.lwf.eus.util;import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;import java.sql.Statement;import javax.naming.Context;import javax.naming.InitialContext;import javax.naming.NamingException;import javax.sql.DataSource;public class ConnectionManager {public static Connection getConnection() {Connection conn = null;String url = "jdbc:postgresql://192.168.0.180/getseus";String userName = "getsdbadmin";String pwd = "powerdb";try {Class.forName("org.postgresql.Driver").newInstance();conn = DriverManager.getConnection(url, userName, pwd);} catch (SQLException e) {e.printStackTrace();} catch (ClassNotFoundException e) {e.printStackTrace();} catch (InstantiationException e) {e.printStackTrace();} catch (IllegalAccessException e) {e.printStackTrace();} catch (Exception e) {e.printStackTrace();}return conn;}public static Connection getConnectionFromDS() {Connection conn = null;Context ctx = null;try {ctx = new InitialContext();DataSource ds = (DataSource) ctx.lookup("JNDIPG");conn = ds.getConnection();} catch (NamingException e) {// TODO Auto-generated catch blocke.printStackTrace();} catch (SQLException e) {// TODO Auto-generated catch blocke.printStackTrace();}return conn;}public static Statement createStatement(Connection conn) {Statement st = null;try {st = conn.createStatement();} catch (SQLException e) {e.printStackTrace();}return st;}}package com.lwf.eus.bean;public class RocarsBean {private String rocarsId;private String ccrn;public String getRocarsId() {return rocarsId;}public void setRocarsId(String rocarsId) {this.rocarsId = rocarsId;}public String getCcrn() {return ccrn;}public void setCcrn(String ccrn) {this.ccrn = ccrn;}}