标签：java name com 案例 Jedis import ailyt public
案例：
- 案例需求：
- 提供index.html页面，页面中有一个省份 下拉列表
- 当页面加载完成后 发送ajax请求，加载所有省份
代码实现：
ProvinceDao
package com.ailyt.dao;
import com.ailyt.pojo.Province;
import java.util.List;
public interface ProvinceDao {
public List<Province> findAll();
}
ProvinceDaoImpl
package com.ailyt.dao.impl;
import com.ailyt.dao.ProvinceDao;
import com.ailyt.pojo.Province;
import com.ailyt.utils.JDBCUtils;
import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.stat.JdbcDataSourceStat;
import lombok.SneakyThrows;
import org.springframework.jdbc.core.BeanPropertyRowMapper;
import org.springframework.jdbc.core.JdbcTemplate;
import java.io.InputStream;
import java.util.List;
import java.util.Properties;
public class ProvinceDaoImpl implements ProvinceDao {
private JdbcTemplate jdbcTemplate = new JdbcTemplate(JDBCUtils.getDataSource());
@SneakyThrows
@Override
public List<Province> findAll() {
String sql = "select * from province";
List<Province> query = jdbcTemplate.query(sql, new BeanPropertyRowMapper<Province>(Province.class));
return query;
}
}
Province
package com.ailyt.pojo;
public class Province {
private int id;
private String name;
@Override
public String toString() {
return "Province{" +
"id=" + id +
", name='" + name + '\'' +
'}';
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public Province() {
}
public Province(int id, String name) {
this.id = id;
this.name = name;
}
}
ProvinceService
package com.ailyt.service;
import com.ailyt.pojo.Province;
import java.util.List;
public interface ProvinceService {
public List<Province> findAll();
}
ProvinceServiceImpl
package com.ailyt.service.impl;
import com.ailyt.dao.impl.ProvinceDaoImpl;
import com.ailyt.pojo.Province;
import com.ailyt.service.ProvinceService;
import java.util.List;
public class ProvinceServiceImpl implements ProvinceService {
private ProvinceDaoImpl provinceDao = new ProvinceDaoImpl();
@Override
public List<Province> findAll() {
return provinceDao.findAll();
}
}
ProvinceServlet
package com.ailyt.servlet;
import com.ailyt.pojo.Province;
import com.ailyt.service.impl.ProvinceServiceImpl;
import com.ailyt.utils.JedisPoolUtils;
import com.fasterxml.jackson.databind.ObjectMapper;
import redis.clients.jedis.Jedis;
import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;
import java.util.List;
@WebServlet(name = "provinceServlet", value = "/provinceServlet")
public class ProvinceServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
this.doPost(request, response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
ProvinceServiceImpl servlet = new ProvinceServiceImpl();
List<Province> list = servlet.findAll();
ObjectMapper mapper = new ObjectMapper();
String json = mapper.writeValueAsString(list);
response.setContentType("application/json;charset=utf-8");
response.getWriter().write(json);
}
}
JDBCUtils
package com.ailyt.utils;
import com.alibaba.druid.pool.DruidDataSourceFactory;
import javax.sql.DataSource;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.SQLException;
import java.util.Properties;
/**
* JDBC工具类 使用Durid连接池
*/
public class JDBCUtils {
private static DataSource ds ;
static {
try {
//1.加载配置文件
Properties pro = new Properties();
//使用ClassLoader加载配置文件，获取字节输入流
InputStream is = JDBCUtils.class.getClassLoader().getResourceAsStream("druid.properties");
pro.load(is);
//2.初始化连接池对象
ds = DruidDataSourceFactory.createDataSource(pro);
} catch (IOException e) {
e.printStackTrace();
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 获取连接池对象
*/
public static DataSource getDataSource(){
return ds;
}
/**
* 获取连接Connection对象
*/
public static Connection getConnection() throws SQLException {
return ds.getConnection();
}
}
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="js/jquery-3.6.0.min.js"></script>
<script>
$(function () {
//发送ajax请求，加载所有省份数据
$.get("provinceServlet",{}, function (data) {
var province = $("#province");
$(data).each(function () {
var option = "<option name='"+this.id+"'>"+this.name+"</option>";
province.append(option);
});
});
});
</script>
</head>
<body>
<select id="province">
<option>--请选择省份--</option>
</select>
</body>
</html>
案例redis缓存优化
@SneakyThrows
@Override
public String findAllJson() {
Jedis jedis = JedisPoolUtils.getJedis();
String province_json = jedis.get("province");
final boolean condition = province_json == null || province_json.length() ==0;
if (condition) {
System.out.println("redis中没有数据从数据库中查询");
List<Province> ps = provinceDao.findAll();
ObjectMapper mapper = new ObjectMapper();
province_json = mapper.writeValueAsString(ps);
jedis.set("province", province_json);
} else {
System.out.println("redis中有数据，从缓存中查询");
}
jedis.close();
return province_json;
}
标签：java,name,com,案例,Jedis,import,ailyt,public 来源： https://www.cnblogs.com/ailhy/p/16615265.html
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