本文实例为大家分享了ajax实现三级联动效果的具体代码，供大家参考，具体内容如下
1、html代码
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Title</title>
<style type="text/css">
.wrap
{
background-color: beige;
width: 400px;
height: 200px;
margin: 0 auto;
text-align: center;
margin-top: 200px;
}
.wrap select
{
width:130px;
height: 30px;
}
</style>
<script type="text/javascript" src="jquery-1.8.3.min.js"></script>
</head>
<body>
<div class="wrap">
<select >
</select>
<select >
</select>
</div>
<script type="text/javascript">
function getctiydata() {
$("#city").empty();
var pid = $("#province").val();
$.ajax({
url:"/getCitys?pjson"
}).done(function (data) {
for (var i in data)
{
$("#city").append($("<option value='"+ data[i].id +"'>"
+ data[i].name +"</option>"))
}
})
}
$.ajax({
url: "/getAllProvince",
dataType:"json"
}).done(function (data) {
for (var i in data)
{
$("#province").append($("<option value = '"+data[i].id+"'>"
+ data[i].name +"</option>"))
}
getctiydata()
});
$("#province").change(function () {
getctiydata()
})
</script>
</body>
</html>
2、javaservlet
package servlet;
import DButil.DataSourceUtil;
import com.alibaba.fastjson.JSON;
import domain.Province;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import javax.jws.WebService;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
@WebServlet("/getAllProvince")
public class ProvinceServlet extends HttpServlet
{
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
{
resp.setContentType("application/json;charset=utf8");
QueryRunner queryRunner = new QueryRunner(DataSourceUtil.getDataSource());
String sql = "select * from province";
try
{
List<Province> provinces = queryRunner.query(sql, new BeanListHandler<Province>(Province.class));
Object json = JSON.toJSON(provinces);
resp.getWriter().print(json);
} catch (SQLException e)
{
e.printStackTrace();
}
}
}
package servlet;
import DButil.DataSourceUtil;
import com.alibaba.fastjson.JSON;
import domain.City;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import javax.jws.WebService;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.sql.SQLException;
import java.util.List;
@WebServlet("/getCitys")
public class CityServlet extends HttpServlet
{
@Override
protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException
{
resp.setContentType("application/json;charset=utf8");
QueryRunner queryRunner = new QueryRunner(DataSourceUtil.getDataSource());
String pid = req.getParameter("pid");
String sql = "select * from City where pid=?";
try
{
List<City> cities = queryRunner.query(sql, new BeanListHandler<City>(City.class), pid);
Object toJSON = JSON.toJSON(cities);
resp.getWriter().print(toJSON);
} catch (SQLException e)
{
e.printStackTrace();
}
}
}
3、数据库池化
<?xml version="1.0" encoding="UTF-8"?> <c3p0-config> <default-config> <property name="driverClass">com.mysql.jdbc.Driver</property> <property name="jdbcUrl">jdbc:mysql://localhost:3306/text</property> <property name="user">root</property> <property name="password">root</property> <property name="acquireRetryAttempts">0</property> </default-config> </c3p0-config>
