java数据访问(2)：DBUtils

        <dependency>
            <groupId>commons-dbutils</groupId>
            <artifactId>commons-dbutils</artifactId>
            <version>1.5</version>
        </dependency>

        <!-- 导入Mysql数据库链接jar包 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.6</version>
        </dependency>

package my;

public class User {

    private Long userid;
    private String username;
    private String password;
    private String comment;


    public Long getUserid() {
        return userid;
    }
    public void setUserid(Long userid) {
        this.userid = userid;
    }

 

    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }


    
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }


    
    public String getComment() {
        return comment;
    }
    public void setComment(String comment) {
        this.comment = comment;
    }
     
}

package my;

import java.sql.Connection;
import java.sql.SQLException;

import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;

public class Insert {

    public static void main(String[] args) throws SQLException {

        Connection conn = ConnectionHelper.getConnection();
        String sql = "insert into user(username, password) values(?,?)";
        QueryRunner queryRunner = new QueryRunner();
        try {

            Object[] params = { "hehe", "123" };

            int i = queryRunner.update(conn, sql, params);

            System.out.println(i);

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DbUtils.close(conn);
        }

    }

}

package my;

import java.sql.Connection;
import java.sql.SQLException;

import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;

public class Delete {

    public static void main(String[] args) throws SQLException {

        Connection conn = ConnectionHelper.getConnection();
        String sql = "delete from user where userId=11";

        QueryRunner queryRunner = new QueryRunner();
        try {

            int i = queryRunner.update(conn, sql);

            System.out.println(i);

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DbUtils.close(conn);
        }

    }

}

package my;

import java.sql.Connection;
import java.sql.SQLException;

import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;

public class Update {

    public static void main(String[] args) throws SQLException {

        Connection conn = ConnectionHelper.getConnection();
        String sql = "update user set userName=?, password=?  where userId=?";

        QueryRunner queryRunner = new QueryRunner();
        try {

            Object[] params = { "wowo", "123", 10 };

            int i = queryRunner.update(conn, sql, params);

            System.out.println(i);

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            DbUtils.close(conn);
        }

    }

}

package my;

import java.sql.Connection;
import java.sql.SQLException;

import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.ResultSetHandler;
import org.apache.commons.dbutils.handlers.BeanHandler;

public class Select1 {

    public static void main(String[] args) throws SQLException {

        Connection conn = ConnectionHelper.getConnection();
        String sql = "select * from user";
        QueryRunner queryRunner = new QueryRunner();
        try {

            ResultSetHandler<User> handler = new BeanHandler<User>(User.class);

            User user = queryRunner.query(conn, sql, handler);

            System.out.println(user.getUserid() + "  " + user.getUsername()
                    + "  " + user.getPassword());

        } catch (Exception ex) {
            ex.printStackTrace(System.out);
        } finally {
            DbUtils.close(conn);
        }
    }

}

package my;

import java.sql.Connection;
import java.sql.SQLException;
import java.util.List;

import org.apache.commons.dbutils.DbUtils;
import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.ResultSetHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;

public class SelectList {

    public static void main(String[] args) throws SQLException {

        Connection conn = ConnectionHelper.getConnection();
        String sql = "select * from user";
        QueryRunner queryRunner = new QueryRunner();
        try {

            ResultSetHandler<List<User>> handler = new BeanListHandler<User>(
                    User.class);

            List<User> users = queryRunner.query(conn, sql, handler);

            for (User user : users) {
                System.out.println(user.getUserid() + "  " + user.getUsername()
                        + "  " + user.getPassword());
            }

        } catch (Exception ex) {
            ex.printStackTrace(System.out);
        } finally {
            DbUtils.close(conn);
        }
    }

}