QueryRunner的添加與查詢操作

Apache-DBUtils實現CRUD操作，commmons-dbutils是Apache組織提供的開源JDBC工具類，

封裝了針對於數據庫的增刪改查操作，Class QueryRunner 

TestQueryRunner

package com.aff.util;
import java.sql.Connection;
import java.sql.Date;
import java.util.List;
import java.util.Map;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.MapHandler;
import org.apache.commons.dbutils.handlers.MapListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;
import org.junit.Test;
import com.aff.bean.Customer;

//commmons-dbutils是Apache組織提供的一個開源的jdbc工具類庫，
//封裝了針對於數據庫的增刪改查操作
public class TestQueryRunner {
    // 測試插入
    @Test
    public void testInsert() {
        Connection conn = null;
        try {
            QueryRunner runner = new QueryRunner();
            conn = JDBCUtilsDruid.getConnection();
            String sql = "insert into customers (name,email,birth)values(?,?,?)";
            runner.update(conn, sql, "蔡徐坤", "[e-mail]", "1997-2-24");
            System.out.println("添加成功");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtilsDruid.closeResource(conn, null, null);
        }
    }

    
    
    // 測試查詢
    // ResultSetHandler 是個接口
    // BeanHander是ResultSetHandler接口的實現類，用於封裝表中的一條記錄
    @Test
    public void testQuery1() {
        Connection conn = null;
        try {
            QueryRunner runner = new QueryRunner();
            conn = JDBCUtilsDBCP.getConnection();
            String sql = "select  id,name,birth from customers where id =?";
            BeanHandler<Customer> handler = new BeanHandler<>(Customer.class);
            Customer customer = runner.query(conn, sql, handler, 20);
            System.out.println(customer);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtilsDBCP.closeResource(conn, null, null);
        }
    }

    
    // BeanListHander是ResultSetHandler接口的實現類，用於封裝表中的多條記錄構成的集合
    @Test
    public void testQuery2() throws Exception {
        Connection conn = null;
        try {
            QueryRunner runner = new QueryRunner();
            conn = JDBCUtilsC3P0.getConnection();
            String sql = "select  id,name,birth from customers where id <?";
            BeanListHandler<Customer> handler = new BeanListHandler<>(Customer.class);
            List<Customer> list = runner.query(conn, sql, handler, 20);
            list.forEach(System.out::println);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtilsC3P0.closeResource(conn, null, null);
        }
    }

    
    
    // MapHander是ResultSetHandler接口的實現類，對應表中的一條記錄
    // 將字段及相應字段的值作為map中的key和value
    // 鍵--值 鍵--值 體現 key-value
    // {name=何苗苗, birth=1996-02-03, id=20}
    @Test
    public void testQuery3() throws Exception {
        Connection conn = null;
        try {
            QueryRunner runner = new QueryRunner();
            conn = JDBCUtilsC3P0.getConnection();
            String sql = "select  id,name,birth from customers where id =?";
            MapHandler handler = new MapHandler();
            Map<String, Object> map = runner.query(conn, sql, handler, 20);
            System.out.println(map);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtilsC3P0.closeResource(conn, null, null);
        }
    }

    
    // MapListHander是ResultSetHandler接口的實現類，對應表中的多條記錄
    // 將字段及相應的值作為map中的key和value，將這些map添加到list中
    @Test
    public void testQuery4() throws Exception {
        Connection conn = null;
        try {
            QueryRunner runner = new QueryRunner();
            conn = JDBCUtilsC3P0.getConnection();
            String sql = "select  id,name,birth from customers where id <?";
            MapListHandler listHandler = new MapListHandler();
            List<Map<String, Object>> list = runner.query(conn, sql, listHandler, 20);
            list.forEach(System.out::println);
            /*
              {name=朱茵, birth=2014-01-16, id=16} 
              {name=何苗, birth=2014-01-17, id=18} 
              {name=芳芳, birth=1996-03-04, id=19}
             */
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtilsC3P0.closeResource(conn, null, null);
        }
    }

    
    //
    // ScalarHandler是ResultSetHandler接口的實現類， 用於查詢特殊值
    //返回表中的記錄數
    @Test
    public void testQuery5() throws Exception {
        Connection conn = null;
        try {
            QueryRunner runner = new QueryRunner();
            conn = JDBCUtilsC3P0.getConnection();
            String sql = "select count(*) from customers";
            ScalarHandler handler = new ScalarHandler();
            Long count = (Long) runner.query(conn, sql, handler);
            System.out.println(count);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtilsC3P0.closeResource(conn, null, null);
        }
    }
    // ScalarHandler是ResultSetHandler接口的實現類， 
    //返回表中的最大出生日期
    @Test
    public void testQuery6() throws Exception {
        Connection conn = null;
        try {
            QueryRunner runner = new QueryRunner();
            conn = JDBCUtilsC3P0.getConnection();
            String sql = "select max(birth) from customers";
            ScalarHandler handler = new ScalarHandler();
            Date maxBirth = (Date) runner.query(conn, sql, handler);
            System.out.println(maxBirth);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            JDBCUtilsC3P0.closeResource(conn, null, null);
        }
    }
}

 

 

使用Dbutils關閉資源

例如：

JDBCUtilsC3P0

package com.aff.util;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.apache.commons.dbutils.DbUtils;

import com.mchange.v2.c3p0.ComboPooledDataSource;

//使用C3P0數據庫連接池
public class JDBCUtilsC3P0 {
    // 把池子拿到外邊，連接池一個就夠，需要的連接從池子中拿
    private static ComboPooledDataSource cbpds = new ComboPooledDataSource("helloc3p0");

    public static Connection getConnection() throws SQLException {
        Connection conn = cbpds.getConnection();
        return conn;
    }
    public static void closeResource(Connection conn, PreparedStatement ps, ResultSet rs) {
        // 7.資源的關閉
 DbUtils.closeQuietly(conn); DbUtils.closeQuietly(ps); DbUtils.closeQuietly(rs); }
}