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 id="province">
- </select>
- <select id="city">
- </select>
- </div>
- <script type="text/javascript">
- function getctiydata() {
- $("#city").empty();
- var pid = $("#province").val();
- $.Ajax({
- url: "/getCitys?pid=" + pid,
- dataType: "json"
- }).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>
以上就是省市联动的核心代码.
来源: https://www.jb51.net/article/153161.htm