架构探险 从零开始写javaweb框架书上源码

package org.smart4j.framework.helper; import java.io.BufferedReader; import java.io.InputStream; import java.io.InputStreamReader; import java.sql.Connection; import java.sql.SQLException; import java.util.ArrayList; import java.util.Collection; import java.util.LinkedHashSet; import java.util.List; import java.util.Map; import java.util.Set; import javax.sql.DataSource; import org.apache.commons.dbcp2.BasicDataSource; import org.apache.commons.dbutils.QueryRunner; import org.apache.commons.dbutils.handlers.ArrayHandler; import org.apache.commons.dbutils.handlers.ArrayListHandler; import org.apache.commons.dbutils.handlers.BeanHandler; import org.apache.commons.dbutils.handlers.BeanListHandler; import org.apache.commons.dbutils.handlers.ColumnListHandler; import org.apache.commons.dbutils.handlers.MapHandler; import org.apache.commons.dbutils.handlers.MapListHandler; import org.apache.commons.dbutils.handlers.ScalarHandler; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.smart4j.framework.util.ClassUtil; import org.smart4j.framework.util.CollectionUtil; /** * 数据库操作助手类 * * @author huangyong * @since 1.0.0 */ public final class DatabaseHelper { private static final Logger LOGGER = LoggerFactory.getLogger(DatabaseHelper.class); private static final ThreadLocal<Connection> CONNECTION_HOLDER; private static final QueryRunner QUERY_RUNNER; private static final BasicDataSource DATA_SOURCE; static { CONNECTION_HOLDER = new ThreadLocal<Connection>(); QUERY_RUNNER = new QueryRunner(); DATA_SOURCE = new BasicDataSource(); DATA_SOURCE.setDriverClassName(ConfigHelper.getJdbcDriver()); DATA_SOURCE.setUrl(ConfigHelper.getJdbcUrl()); DATA_SOURCE.setUsername(ConfigHelper.getJdbcUsername()); DATA_SOURCE.setPassword(ConfigHelper.getJdbcPassword()); } /** * 获取数据源 */ public static DataSource getDataSource() { return DATA_SOURCE; } /** * 获取数据库连接 */ public static Connection getConnection() { Connection conn = CONNECTION_HOLDER.get(); if (conn == null) { try { conn = DATA_SOURCE.getConnection(); } catch (SQLException e) { LOGGER.error("get connection failure", e); throw new RuntimeException(e); } finally { CONNECTION_HOLDER.set(conn); } } return conn; } /** * 开启事务 */ public static void beginTransaction() { Connection conn = getConnection(); if (conn != null) { try { conn.setAutoCommit(false); } catch (SQLException e) { LOGGER.error("begin transaction failure", e); throw new RuntimeException(e); } finally { CONNECTION_HOLDER.set(conn); } } } /** * 提交事务 */ public static void commitTransaction() { Connection conn = getConnection(); if (conn != null) { try { conn.commit(); conn.close(); } catch (SQLException e) { LOGGER.error("commit transaction failure", e); throw new RuntimeException(e); } finally { CONNECTION_HOLDER.remove(); } } } /** * 回滚事务 */ public static void rollbackTransaction() { Connection conn = getConnection(); if (conn != null) { try { conn.rollback(); conn.close(); } catch (SQLException e) { LOGGER.error("rollback transaction failure", e); throw new RuntimeException(e); } finally { CONNECTION_HOLDER.remove(); } } } /** * 查询实体 */ public static <T> T queryEntity(Class<T> entityClass, String sql, Object... params) { T entity; try { Connection conn = getConnection(); entity = QUERY_RUNNER.query(conn, sql, new BeanHandler<T>(entityClass), params); } catch (SQLException e) { LOGGER.error("query entity failure", e); throw new RuntimeException(e); } return entity; } /** * 查询实体列表 */ public static <T> List<T> queryEntityList(Class<T> entityClass, String sql, Object... params) { List<T> entityList; try { Connection conn = getConnection(); entityList = QUERY_RUNNER.query(conn, sql, new BeanListHandler<T>(entityClass), params); } catch (SQLException e) { LOGGER.error("query entity list failure", e); throw new RuntimeException(e); } return entityList; } /** * 查询并返回单个列值 */ public static <T> T query(String sql, Object... params) { T obj; try { Connection conn = getConnection(); obj = QUERY_RUNNER.query(conn, sql, new ScalarHandler<T>(), params); } catch (SQLException e) { LOGGER.error("query failure", e); throw new RuntimeException(e); } return obj; } /** * 查询并返回多个列值 */ public static <T> List<T> queryList(String sql, Object... params) { List<T> list; try { Connection conn = getConnection(); list = QUERY_RUNNER.query(conn, sql, new ColumnListHandler<T>(), params); } catch (SQLException e) { LOGGER.error("query list failure", e); throw new RuntimeException(e); } return list; } /** * 查询并返回多个列值（具有唯一性） */ public static <T> Set<T> querySet(String sql, Object... params) { Collection<T> valueList = queryList(sql, params); return new LinkedHashSet<T>(valueList); } /** * 查询并返回数组 */ public static Object[] queryArray(String sql, Object... params) { Object[] resultArray; try { Connection conn = getConnection(); resultArray = QUERY_RUNNER.query(conn, sql, new ArrayHandler(), params); } catch (SQLException e) { LOGGER.error("query array failure", e); throw new RuntimeException(e); } return resultArray; } /** * 查询并返回数组列表 */ public static List<Object[]> queryArrayList(String sql, Object... params) { List<Object[]> resultArrayList; try { Connection conn = getConnection(); resultArrayList = QUERY_RUNNER.query(conn, sql, new ArrayListHandler(), params); } catch (SQLException e) { LOGGER.error("query array list failure", e); throw new RuntimeException(e); } return resultArrayList; } /** * 查询并返回结果集映射（列名 => 列值） */ public static Map<String, Object> queryMap(String sql, Object... params) { Map<String, Object> resultMap; try { Connection conn = getConnection(); resultMap = QUERY_RUNNER.query(conn, sql, new MapHandler(), params); } catch (SQLException e) { LOGGER.error("query map failure", e); throw new RuntimeException(e); } return resultMap; } /** * 查询并返回结果集映射列表（列名 => 列值） */ public static List<Map<String, Object>> queryMapList(String sql, Object... params) { List<Map<String, Object>> resultMapList; try { Connection conn = getConnection(); resultMapList = QUERY_RUNNER.query(conn, sql, new MapListHandler(), params); } catch (SQLException e) { LOGGER.error("query map list fa