/**

 * 自定义JDBC框架

 */

public class JDBCFramework {

	/**

	 * 通用select方法

	 */

	public static <T> T query(String sql, MyResultSetHandler<T> handler,

			Object... args) {

		T obj = null;

		Connection conn = null;

		PreparedStatement stmt = null;

		ResultSet rs = null;

		try {

			conn = JDBCUtils.getConnection();

			stmt = conn.prepareStatement(sql);

			// 设置参数

			ParameterMetaData parameterMetaData = stmt.getParameterMetaData();

			int count = parameterMetaData.getParameterCount();

			for (int i = 1; i <= count; i++) {

				stmt.setObject(i, args[i - 1]);

			}

			rs = stmt.executeQuery();

			obj = handler.handle(rs);

		} catch (SQLException e) {

			e.printStackTrace();

		} finally {

			JDBCUtils.release(rs, stmt, conn);

		}

		return obj;

	}

	/**

	 * 通过insert update delete方法

	 *

	 * @param sql

	 *            预编译需要SQL

	 * @param args

	 *            根据SQL中? 准备参数

	 */

	public static void update(String sql, Object... args) {

		Connection conn = null;

		PreparedStatement stmt = null;

		try {

			conn = JDBCUtils.getConnection();

			stmt = conn.prepareStatement(sql);

			// 设置参数 --- 根据？设置参数

			ParameterMetaData parameterMetaData = stmt.getParameterMetaData();

			int count = parameterMetaData.getParameterCount();

			for (int i = 1; i <= count; i++) {

				stmt.setObject(i, args[i - 1]);

			}

			stmt.executeUpdate();

		} catch (SQLException e) {

			e.printStackTrace();

		} finally {

			JDBCUtils.release(stmt, conn);

		}

	}

}

public interface MyResultSetHandler<T> {

	// 将rs中数据封装对象

	public T handle(ResultSet rs);

}

/**

 * 通用handler，处理将所有rs第一行数据 转换指定 JavaBean对象

 */

public class MyBeanHandler<T> implements MyResultSetHandler<T> {

	private Class<T> domainClass;

	public MyBeanHandler(Class<T> domainClass) {

		this.domainClass = domainClass;

	}

	@Override

	public T handle(ResultSet rs) {

		try {

			ResultSetMetaData resultSetMetaData = rs.getMetaData();// 结果集元数据

			int count = resultSetMetaData.getColumnCount();

			BeanInfo beanInfo = Introspector.getBeanInfo(domainClass);

			PropertyDescriptor[] descriptors = beanInfo

					.getPropertyDescriptors();

			if (rs.next()) {

				T t = domainClass.newInstance();

				for (int i = 1; i <= count; i++) {

					String columnName = resultSetMetaData.getColumnName(i);

					// 获得列名 --- 需要去查找匹配属性

					for (PropertyDescriptor propertyDescriptor : descriptors) {

						if (columnName.equals(propertyDescriptor.getName())) {

							// 列名 存在 同名属性 ---- 列值 存到属性里

							Method writeMethod = propertyDescriptor

									.getWriteMethod(); // setName setMoney

							writeMethod.invoke(t, rs.getObject(columnName));

						}

					}

				}

				return t;

			}

		} catch (Exception e) {

			e.printStackTrace();

		}

		return null;

	}

}