908~909Maven工程环境修改，Maven的Java工程取mysql数据库数据

Maven工程环境修改

<plugins>
            <plugin>
                <!-- https://mvnrepository.com/artifact/org.apache.tomcat.maven/tomcat7-maven-plugin -->
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <version>2.2</version>
                <configuration>
                    <port>8888</port>
                </configuration>
            </plugin>
</plugins>

Maven的Java工程取mysql数据库数据

实体类
package com.example.day_24_maavenmysql.domain;
 
public class Items {
    private Integer id;
    private String name;
 
    public Integer getId() {
        return id;
    }
 
    public void setId(Integer id) {
        this.id = id;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
}

接口
 
package com.example.day_24_maavenmysql.dao;
 
import com.example.day_24_maavenmysql.domain.Items;
 
import java.util.List;
 
public interface ItemsDao {
    public List<Items> findAll();
}

实现接口
 
 
package com.example.day_24_maavenmysql.dao.impl;
 
 
 
import com.example.day_24_maavenmysql.dao.ItemsDao;
import com.example.day_24_maavenmysql.domain.Items;
 
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;
 
/**
 * 要想从数据库中取出数据
 * 必须有四个属性：数据库驱动，连接数据库的地址，数据库用户名称，数据库密码。
 */
public class ItemsDaoImpl implements ItemsDao {
    public List<Items> findAll(){
        List<Items> list = new ArrayList<Items>();
        //先获取contection对象
        Connection connection = null;
        //获取真正操作数据的对象
        PreparedStatement pst = null;
        //执行数据库查询操作
        ResultSet rs = null;
        try {
            //加载驱动类
            Class.forName("com.mysql.jdbc.Driver");
            //先获取contection对象
            connection = DriverManager.getConnection("jdbc:mysql:///kaohe","root", "root");
            //获取真正操作数据的对象
            pst = connection.prepareCall("select * from province");
            //执行数据库查询操作
           rs = pst.executeQuery();
            //把数据库结果集转成java的List集合
 
            while (rs.next()){
                Items items = new Items();
                items.setId(rs.getInt("id"));
                items.setName(rs.getString("name"));
                list.add(items);
            }
        }catch (Exception e){
            e.printStackTrace();
        }
 
        return list;
    }
}

测试类
 
 
import com.example.day_24_maavenmysql.dao.ItemsDao;
import com.example.day_24_maavenmysql.dao.impl.ItemsDaoImpl;
import com.example.day_24_maavenmysql.domain.Items;
import org.junit.Test;
 
import java.util.List;
 
public class ttest {
 
        @Test
        public void findAll(){
            ItemsDao itemsDao = new ItemsDaoImpl();
            List<Items> list = itemsDao.findAll();
            for (Items items : list) {
                System.out.println(items.getName());
            }
        }
    }