DbUtils的简单使用范例，dbutils范例,DButils是Apac

DbUtils的简单使用范例，dbutils范例,DButils是Apac

DButils是Apache的一个开源数据库访问框架```javaimport java.sql.ResultSet;import java.sql.SQLException;import java.util.List;

import javax.sql.DataSource;

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

import com.mysql.jdbc.jdbc2.optional.MysqlDataSource;

public class UserDaoImpl implements UserDao {

public DataSource getDataSource(){    String url = "jdbc:mysql://127.0.0.1:3306/testdbutils";    MysqlDataSource ds = new MysqlDataSource();    ds.setServerName("127.0.0.1");

// ds.setDatabaseName("testdbutils"); ds.setURL(url); ds.setUser("root"); ds.setPassword("123456"); ds.setCharacterEncoding("utf8"); return ds; }

public BeanListHandler<User> getBeanListHandler(){    return new BeanListHandler<User>(User.class);}public BeanHandler<User> getBeanHandler(){    return new BeanHandler<User>(User.class);}public void delete(int id) {    QueryRunner runner = new QueryRunner(getDataSource());    try {        int affectedRows = runner.update("delete from user where id = ?",id);        System.out.println("删除成功，影响的行数："+affectedRows);    } catch (SQLException e) {        System.out.println("删除id为"+id+"的记录失败。错误为："+e.getMessage());    }}public void delete(User user) {    delete(user.getId());}public List<User> getAllUsers() {    QueryRunner runner = new QueryRunner(getDataSource());    try {        return runner.query("select * from user", getBeanListHandler());    } catch (SQLException e) {        e.printStackTrace();        return null;    }}public User getById(int id) {    QueryRunner runner = new QueryRunner(getDataSource());    User user = null;    try {        user = runner.query("select * from user where id = ?", getBeanHandler(),id);    } catch (SQLException e) {        e.printStackTrace();    }    return user;}public void save(User user) {    QueryRunner runner = new QueryRunner(getDataSource());    try {        runner.update("insert into user values(?,?,?,?,?)",new Object[]{                user.getId(),                user.getName(),                user.getAge(),                user.getSex(),                user.getBirth()        });    } catch (SQLException e) {        System.out.println("插入失败，失败原因:"+e.getMessage());    }}public long getCount() {    QueryRunner runner = new QueryRunner(getDataSource());    try {        Long count = runner.query("select count(*) as count from user", new ResultSetHandler<Long>(){            public Long handle(ResultSet rs) throws SQLException {                if(rs.next()){                    return rs.getLong(1); //或者rs.getLong("count");                }                return 0L;            }        });        //或者用ScalarHandler, 这里的new ScalarHandler() 可以加上“count”参数

// Long count = (Long)runner.query("select count(*) as count from user",new ScalarHandler(){//// @Override// public Object handle(ResultSet rs) throws SQLException {// return super.handle(rs);// }//
// });

        return (Long)count;    } catch (SQLException e) {        e.printStackTrace();        return 0L;    }}

}```