commons-dbutils Helper

封装下dbutils, 使用这个help去操作数据库会非常的方便，下面还提供了例子.

package com.kneel.core.help;

import java.io.IOException;

/**
 * just wrap DbUtils QueryRunner, provider simple functions to use.
 * 
 * give chance to add action and do operator
 * 
 * query: resolve all query problem. insert: get secuqnce to insert update:
 * execute update with params. delete: execute delete with params batch: batch
 * update and delete with params.
 * 
 * NOTE: batch operator, please cause of batchSize, this will be set how many
 * counts we commit, and do next batch.
 * 
 * NOTE: below have expand of Connection PARAMS, if call please add.
 * 
 * NOTE: if query large Datas, please set FecthSize, this will be improve
 * performance.
 * 
 * we often use Bean to setter/getter, with columnToPropertyOverrides,we use
 * this to process column name not same as property. or we can do below SELECT
 * event_id id, event_date date,title from events. this will be re-name column
 * lable name.(care of key of Database)
 * 
 * queryBean: query one row to Bean queryBeanList: query multiple rows to
 * List<Bean> queryBeanMap: query multiple rows to Map<String,Bean>
 * 
 * Query List application
 * 
 * queryColumn: query one column value queryColumnSqlKey: query one column value
 * with sql key queryMap: query one row to Map<String,Object> queryKeyMap: query
 * multiple rows to Map<Object,Map<String,Object>> queryListMap: query multiple
 * rows to List<Map<String,Object>> queryArray: query one row to Object[]
 * queryArrayList: query multiple rows to List<Object[]>
 * 
 * 
 * 
 * Example one: easy to queryBean.
 * 
 * String sql = "SELECT * FROM EVENTS WHERE EVENT_ID = ?"; Object[] params = new
 * Object[] { 130L }; Event event = helper.queryBean(sql, Event.class, params);
 * //Event event = helper.queryBean(sql, Event.class,130L);
 * 
 * Example two: Column not match property
 * 
 * Map<String, String> columnToPropertyOverrides = new HashMap<String,String>();
 * columnToPropertyOverrides.put("EVENT_ID", "id");
 * columnToPropertyOverrides.put("EVENT_DATE", "date"); String sql =
 * "SELECT * FROM EVENTS WHERE EVENT_ID = ?"; Object[] params = new Object[] {
 * 130L }; Event event = helper.queryBean(sql,
 * Event.class,columnToPropertyOverrides, params);
 * 
 * Example three: easy to insert
 * 
 * String sql = "INSERT into events(event_id,event_date,title) VALUES(?,?,?)";
 * Object[] params = new Object[] { event.getDate(),event.getTitle() }; Long id
 * = helper.insert(sql, "events_sequnce", params);
 * 
 * Example four: easy to query one column String sql =
 * "SELECT count(*) eventCount  FROM events"; Object count =
 * helper.queryColumn(sql, "eventCount");
 * 
 * Example five: easy to get one column multiple rows List<ID>
 * 
 * String sql = "SELECT event_id  FROM events"; List<Object> count =
 * helper.queryColumnList(sql, "event_id");
 * 
 * Example six: easy to do it in batch
 * 
 * String sql =
 * "UPDATE events SET event_date = ?, title = ? WHERE event_id = ?"; Object[][]
 * params = new Object[events.size()][]; for(int i=0 i< events.size();i++){
 * Event event = events.get(i); params[i] = new Object[] {
 * event.getDate(),event.getTitle(),event.getId()}; } int[] effectrows =
 * helper.batch(sql, params);
 * 
 * Example seven: easy to do insert batch, return all ids.
 * 
 * String sql = "INSERT into events(event_id,event_date,title) VALUES(?,?,?)";
 * Object[][] params = new Object[events.size()][]; for(int i=0 i<
 * events.size();i++){ Event event = events.get(i); params[i] = new Object[] {
 * event.getDate(),event.getTitle()}; } Long[] ids =
 * helper.insertBatch(sql,"events_sequnce" ,params);
 * 
 * @author e557400
 * 
 */
public class DatabaseHelper {

	private static final Log log = LogFactory.getLog(DatabaseHelper.class);
	private static final String DEFAULT_DS_KEY = "DEFAULT";
 
	private DataSource dataSource = null;
	private static Map<String,DataSource> cachds = new ConcurrentHashMap<String,DataSource>(); 
	private QueryRunner queryRunner = null;
	private Map<String, String> sqlKeys = new HashMap<String, String>();

	public DatabaseHelper() {
		this(null, null);
	}

	public DatabaseHelper(String path) {
		this(null, path);
	}

	public DatabaseHelper(DataSource dataSource) {
		this(dataSource, null);
	}

	public DatabaseHelper(DataSource dataSource, String path) {
		this(dataSource,path,0);
	}
	
	public DatabaseHelper(DataSource dataSource, String path, final int fecthSize) { 
		if (dataSource == null) {
			dataSource = initDataSource();
		} 
		String dskey = dataSource.toString()+fecthSize; 
		DataSource ds = cachds.get(dskey);
		if(ds == null){
			this.dataSource = dataSource;
			queryRunner = new QueryRunner(dataSource){
				protected PreparedStatement prepareStatement(Connection conn, String sql)
			            throws SQLException {
					PreparedStatement stmt = conn.prepareStatement(sql);
					if(fecthSize>0){
						stmt.setFetchSize(fecthSize);
					}
			        return stmt;
			    }
			};
			cachds.put(dskey, dataSource);
		} 
		
		if (path != null) {
			sqlKeys = loadQueries(path);
		}
	}

	/**
	 * Executes the given SELECT SQL without any replacement parameters. The
	 * <code>Connection</code> is retrieved from the <code>DataSource</code> set
	 * in the constructor.
	 * 
	 * @param <T>
	 *            The type of object that the handler returns
	 * @param sql
	 *            The SQL statement to execute.
	 * @param rsh
	 *            The handler used to create the result object from the
	 *            <code>ResultSet</code>.
	 * 
	 * @return An object generated by the handler.
	 * @throws SQLException
	 *             if a database access error occurs
	 */
	public <T> T query(String sql, ResultSetHandler<T> rsh) throws SQLException {
		return queryRunner.query(sql, rsh);
	}

	/**
	 * Executes the given SELECT SQL query and returns a result object. The
	 * <code>Connection</code> is retrieved from the <code>DataSource</code> set
	 * in the constructor.
	 * 
	 * @param <T>
	 *            The type of object that the handler returns
	 * @param sql
	 *            The SQL statement to execute.
	 * @param rsh
	 *            The handler used to create the result object from the
	 *            <code>ResultSet</code>.
	 * @param params
	 *            Initialize the PreparedStatement's IN parameters with this
	 *            array.
	 * @return An object generated by the handler.
	 * @throws SQLException
	 *             if a database access error occurs
	 */
	public <T> T query(String sql, ResultSetHandler<T> rsh, Object... params)
			throws SQLException {
		return queryRunner.query(sql, rsh, params);
	}

	/**
	 * Execute an SQL SELECT query without any replacement parameters. The
	 * caller is responsible for closing the connection.
	 * 
	 * @param <T>
	 *            The type of object that the handler returns
	 * @param conn
	 *            The connection to execute the query in.
	 * @param sql
	 *            The query to execute.
	 * @param rsh
	 *            The handler that converts the results into an object.
	 * @return The object returned by the handler.
	 * @throws SQLException
	 *             if a database access error occurs
	 */
	public <T> T query(Connection conn, String sql, ResultSetHandler<T> rsh)
			throws SQLException {
		return queryRunner.query(conn, sql, rsh);
	}

	/**
	 * Execute an SQL SELECT query with replacement parameters. The caller is
	 * responsible for closing the connection.
	 * 
	 * @param <T>
	 *            The type of object that the handler returns
	 * @param conn
	 *            The connection to execute the query in.
	 * @param sql
	 *            The query to execute.
	 * @param rsh
	 *            The handler that converts the results into an object.
	 * @param params
	 *            The replacement parameters.
	 * @return The object returned by the handler.
	 * @throws SQLException
	 *             if a database access error occurs
	 */
	public <T> T query(Connection conn, String sql, ResultSetHandler<T> rsh,
			Object... params) throws SQLException {
		return queryRunner.query(conn, sql, rsh, params);
	}

	/**
	 * Executes the given INSERT, UPDATE, or DELETE SQL statement without any
	 * replacement parameters. The <code>Connection</code> is retrieved from the
	 * <code>DataSource</code> set in the constructor. This
	 * <code>Connection</code> must be in auto-commit mode or the update will
	 * not be saved.
	 * 
	 * @param sql
	 *            The SQL statement to execute.
	 * @throws SQLException
	 *             if a database access error occurs
	 * @return The number of rows updated.
	 */
	public int update(String sql) throws SQLException {
		return queryRunner.update(sql);
	}

	/**
	 * Executes the given INSERT, UPDATE, or DELETE SQL statement. The
	 * <code>Connection</code> is retrieved from the <code>DataSource</code> set
	 * in the constructor. This <code>Connection</code> must be in auto-commit
	 * mode or the update will not be saved.
	 * 
	 * @param sql
	 *            The SQL statement to execute.
	 * @param params
	 *            Initializes the PreparedStatement's IN (i.e. '?') parameters.
	 * @throws SQLException
	 *             if a database access error occurs
	 * @return The number of rows updated.
	 */
	public int update(String sql, Object... params) throws SQLException {
		return queryRunner.update(sql, params);
	}

	/**
	 * Execute an SQL INSERT, UPDATE, or DELETE query without replacement
	 * parameters.
	 * 
	 * @param conn
	 *            The connection to use to run the query.
	 * @param sql
	 *            The SQL to execute.
	 * @return The number of rows updated.
	 * @throws SQLException
	 *             if a database access error occurs
	 */
	public int update(Connection conn, String sql) throws SQLException {
		return queryRunner.update(conn, sql);
	}

	/**
	 * Execute an SQL INSERT, UPDATE, or DELETE query.
	 * 
	 * @param conn
	 *            The connection to use to run the query.
	 * @param sql
	 *            The SQL to execute.
	 * @param params
	 *            The query replacement parameters.
	 * @return The number of rows updated.
	 * @throws SQLException
	 *             if a database access error occurs
	 */
	public int update(Connection conn, String sql, Object... params)
			throws SQLException {
		return queryRunner.update(conn, sql, params);
	}

	/**
	 * Execute a batch of SQL INSERT, UPDATE, or DELETE queries. The
	 * <code>Connection</code> is retrieved from the <code>DataSource</code> set
	 * in the constructor. This <code>Connection</code> must be in auto-commit
	 * mode or the update will not be saved.
	 * 
	 * @param sql
	 *            The SQL to execute.
	 * @param params
	 *            An array of query replacement parameters. Each row in this
	 *            array is one set of batch replacement values.
	 * @return The number of rows updated per statement.
	 * @throws SQLException
	 *             if a database access error occurs
	 * @since DbUtils 1.1
	 */
	public int[] batch(String sql, Object[][] params) throws SQLException {
		return queryRunner.batch(sql, params);
	}

	/**
	 * Execute a batch of SQL INSERT, UPDATE, or DELETE queries.
	 * 
	 * @param conn
	 *            The Connection to use to run the query. The caller is
	 *            responsible for closing this Connection.
	 * @param sql
	 *            The SQL to execute.
	 * @param params
	 *            An array of query replacement parameters. Each row in this
	 *            array is one set of batch replacement values.
	 * @return The number of rows updated per statement.
	 * @throws SQLException
	 *             if a database access error occurs
	 * @since DbUtils 1.1
	 */
	public int[] batch(Connection conn, String sql, Object[][] params)
			throws SQLException {
		return queryRunner.batch(conn, sql, params);
	}

	/**
	 * Execute a batch of SQL INSERT, UPDATE, or DELETE queries, use batchSize to execute.
	 * 
	 * @param sql
	 *            The SQL to execute.
	 * @param params
	 *            An array of query replacement parameters. Each row in this
	 *            array is one set of batch replacement values.
	 * @param batchSize
	 *            how many rows we should execute once
	 * @return The number of rows updated per statement.
	 * @throws SQLException
	 *             if a database access error occurs
	 */
	public int[] batch(String sql, Object[][] params, int batchSize)
			throws SQLException {
		Connection conn = dataSource.getConnection();
		int[] effects = new int[params.length];
		if (supportsBatchUpdates(conn)) {
			int n = 0;
			int batchIndex = 0;
			Object[][] batch = new Object[batchSize][];
			for (Object[] paramsc : params) {
				batch[n++ % batchSize] = paramsc;
				if (n % batchSize == 0 || n == params.length) {
					int batchIdx = (n % batchSize == 0) ? n / batchSize
							: (n / batchSize) + 1;
					int items = n
							- ((n % batchSize == 0) ? n / batchSize - 1
									: (n / batchSize)) * batchSize;
					log.debug("Sending SQL batch update #" + batchIdx
							+ " with " + items + " items");
					if (n % batchSize != 0) {// batch is less then batchSize.
						batch = Arrays.copyOf(batch, n % batchSize);
					}
					int[] effectbatchs = batch(conn, sql, batch);
					for (int effectbatch : effectbatchs) {
						effects[batchIndex++] = effectbatch;
					}
					// after process, clear
					batch = new Object[batchSize][];
				}

			}
		} else {
			int index = 0;
			for (Object[] paramsc : params) {
				effects[index++] = update(conn, sql, paramsc);
			}
		}
		conn.close();
		return effects;
	}

	/**
	 * Execute a batch of SQL INSERT, UPDATE, or DELETE queries, use batchSize to execute.
	 * 
	 * @param conn
	 *            The Connection to use to run the query. The caller is
	 *            responsible for closing this Connection.
	 * @param sql
	 *            The SQL to execute.
	 * @param params
	 *            An array of query replacement parameters. Each row in this
	 *            array is one set of batch replacement values.
	 * @param batchSize
	 *            how many rows we should execute once
	 * @return The number of rows updated per statement.
	 * @throws SQLException
	 *             if a database access error occurs
	 */
	public int[] batch(Connection conn, String sql, Object[][] params,
			int batchSize) throws SQLException {
		if (supportsBatchUpdates(conn)) {
			int n = 0;
			Object[][] batch = new Object[batchSize][];
			int[] effects = new int[params.length];
			for (Object[] paramsc : params) {
				batch[n++ % batchSize] = paramsc;
				if (n % batchSize == 0 || n == params.length) {
					int batchIdx = (n % batchSize == 0) ? n / batchSize
							: (n / batchSize) + 1;
					int items = n
							- ((n % batchSize == 0) ? n / batchSize - 1
									: (n / batchSize)) * batchSize;
					log.debug("Sending SQL batch update #" + batchIdx
							+ " with " + items + " items");
					int[] effectbatchs = batch(conn, sql, batch);
					for (int effectbatch : effectbatchs) {
						effects[batchIdx * batchSize + n] = effectbatch;
					}
				}
			}
			return effects;
		} else {
			int[] effects = new int[params.length];
			int index = 0;
			for (Object[] paramsc : params) {
				effects[index++] = update(conn, sql, paramsc);
			}
			return effects;
		}
	}

	/**
	 * Oracle insert, give sequnceName to insert.
	 *    1.  to get next SequnceId, then we all use it as Long.
	 *    2.  add this sequnceId to params[0], add all others to index++.
	 *    3.  Execute an SQL INSERT, and return effect row.
	 *    4.  if effect row is not 0, then success, or exception.
	 *  
	 * @param sql
	 * @param sequnceName
	 * @param params
	 * @return
	 * @throws SQLException
	 */
	public Long insert(String sql, String sequnceName, Object... params)
			throws SQLException {
		Connection conn = dataSource.getConnection();
		Long id = insert(conn, sql, sequnceName, params);
		conn.close();
		return id;
	}
	
	/**
	 * Oracle insert, give sequnceName to insert.
	 *    1.  to get next SequnceId, then we all use it as Long.
	 *    2.  add this sequnceId to params[0], add all others to index++.
	 *    3.  Execute an SQL INSERT, and return effect row.
	 *    4.  if effect row is not 0, then success, or exception.
	 * 
	 * @param conn
	 * @param sql
	 * @param sequnceName
	 * @param params
	 * @return
	 * @throws SQLException
	 */
	public Long insert(Connection conn, String sql, String sequnceName,
			Object... params) throws SQLException {
		// get sequnce id
		Long sequnceId = null;
		String sequnceSql = getSequnceSql(sequnceName);
		ScalarHandler<Object> rsh = new ScalarHandler<Object>();
		Object keyId = query(conn, sequnceSql, rsh);
		if (Number.class.isAssignableFrom(keyId.getClass())) {
			sequnceId = Long.valueOf(((Number) keyId).longValue());
		}

		// add params to first of the params
		Object[] paramsCopy = new Object[params.length + 1];
		paramsCopy[0] = sequnceId;
		int index = 1;
		for (Object param : params) {
			paramsCopy[index++] = param;
		}

		int effect = update(conn, sql, paramsCopy);
		if (effect != 0) {// insert success
			return sequnceId;
		} else {
			throw new SQLException("Insert fail, please check params[" + sql
					+ "," + sequnceName + "," + params + "]");
		}
	}

	/**
	 * Oracle insert Batch, give sequnceName to insert.(Batch)
	 *    1.  to get next SequnceId, then we all use it as Long.
	 *    2.  add this sequnceId to params[0], add all others to index++.
	 *    3.  Execute an SQL INSERT, and return effect row.
	 *    4.  if effect row is not 0, then success, or exception.
	 * 
	 * @param conn
	 * @param sql
	 * @param sequnceName
	 * @param params
	 * @return
	 * @throws SQLException
	 */
	public Long[] insertBatch(String sql, String sequnceName, Object params[][])
			throws SQLException {
		Connection conn = dataSource.getConnection();
		Long[] id = insertBatch(conn, sql, sequnceName, params);
		conn.close();
		return id;
	}
	
	

	/**
	 * Oracle insert Batch, give sequnceName to insert.(Batch)
	 * 
	 * @param conn
	 * @param sql
	 * @param sequnceName
	 * @param paramAlls
	 * @return
	 * @throws SQLException
	 */
	public Long[] insertBatch(Connection conn, String sql, String sequnceName,
			Object[][] paramAlls) throws SQLException {
		Object[][] parambatchs = new Object[paramAlls.length][];
		Long[] ids = new Long[paramAlls.length];
		for (int i = 0; i < paramAlls.length; i++) {
			Object[] paramAll = paramAlls[i];
			// get sequnce id
			Long id = null;
			String sequnceSql = getSequnceSql(sequnceName);
			ScalarHandler<Object> rsh = new ScalarHandler<Object>();
			Object keyId = query(conn, sequnceSql, rsh);
			if (Number.class.isAssignableFrom(keyId.getClass())) {
				id = Long.valueOf(((Number) keyId).longValue());
				ids[i] = id;
			}

			// add params to first of the params
			Object[] paramsCopy = new Object[paramAll.length + 1];
			paramsCopy[0] = id;
			int index = 1;
			for (Object param : paramAll) {
				paramsCopy[index++] = param;
			}
			parambatchs[i] = paramsCopy;
		}

		batch(conn, sql, parambatchs);

		return ids;
	}
	

	/**
	 * Oracle insert Batch, give sequnceName to insert.(Batch)
	 *    1.  to get next SequnceId, then we all use it as Long.
	 *    2.  add this sequnceId to params[0], add all others to index++.
	 *    3.  Execute an SQL INSERT, and return effect row.
	 *    4.  if effect row is not 0, then success, or exception.
	 * 
	 * @param conn
	 * @param sql
	 * @param sequnceName
	 * @param params
	 * @return
	 * @throws SQLException
	 */
	public Long[] insertBatch(String sql, String sequnceName, Object params[][],int batchSize) throws SQLException {
		Connection conn = dataSource.getConnection();
		Long[] id = insertBatch(conn, sql, sequnceName, params,batchSize);
		conn.close();
		return id;
	}
	
	/**
	 * Oracle insert Batch, give sequnceName to insert.(Batch)
	 * 
	 * @param conn
	 * @param sql
	 * @param sequnceName
	 * @param paramAlls
	 * @return
	 * @throws SQLException
	 */
	public Long[] insertBatch(Connection conn, String sql, String sequnceName,
			Object[][] paramAlls,int batchSize) throws SQLException {
		
		if (supportsBatchUpdates(conn)) {
			int n = 0;
			Object[][] batch = new Object[batchSize][];
			Long[] ids = new Long[paramAlls.length];
			int batchIndex = 0;
			for (Object[] paramsc : paramAlls) {
				batch[n++ % batchSize] = paramsc;
				if (n % batchSize == 0 || n == paramAlls.length) {
					int batchIdx = (n % batchSize == 0) ? n / batchSize
							: (n / batchSize) + 1;
					int items = n
							- ((n % batchSize == 0) ? n / batchSize - 1
									: (n / batchSize)) * batchSize;
					log.debug("Sending SQL batch insert #" + batchIdx
							+ " with " + items + " items");
					if (n % batchSize != 0) {// batch is less then batchSize.
						batch = Arrays.copyOf(batch, n % batchSize);
					}
					Long[] idsubs = insertBatch(conn, sql,sequnceName, batch);
					for (Long idsub : idsubs) {
						ids[batchIndex++] = idsub;
					}
					// after process, clear
					batch = new Object[batchSize][];
				}
			}
			return ids;
		} else {
			Long[] ids = new Long[paramAlls.length];
			int index = 0;
			for (Object[] paramsc : paramAlls) {
				ids[index++] = insert(conn, sql,sequnceName, paramsc);
			}
			return ids;
		}  
	}
 

	/**
	 * execute SQL, transform ResultSet to Class<T>[Bean]
	 * 
	 * @param sql
	 *            query SQL
	 * @param clazz
	 *            target Class
	 * @return
	 * @throws SQLException
	 */
	public <T> T queryBean(String sql, final Class<T> clazz)
			throws SQLException {
		return queryBean(sql, clazz, new HashMap<String, String>());
	}

	/**
	 * execute SQL, transform ResultSet to Class<T>[Bean]
	 * 
	 * @param columnToPropertyOverrides
	 *            column to property overrides
	 * @return
	 * @throws SQLException
	 */
	public <T> T queryBean(String sql, final Class<T> clazz, Object... params)
			throws SQLException {
		return queryBean(sql, clazz, new HashMap<String, String>(), params);
	}

	/**
	 * execute SQL, transform ResultSet to Class<T>[Bean]
	 * 
	 * @param params
	 *            SQL PARAMS
	 * @param columnToPropertyOverrides
	 *            column to property overrides
	 * @return
	 * @throws SQLException
	 */
	public <T> T queryBean(String sql, final Class<T> clazz,
			final Map<String, String> columnToPropertyOverrides,
			Object... params) throws SQLException {
		ResultSetHandler<T> rsh = new ResultSetHandler<T>() {
			@Override
			public T handle(ResultSet rs) throws SQLException {
				BeanProcessor bp = new BeanProcessor(columnToPropertyOverrides);
				if (rs.next()) {
					return bp.toBean(rs, clazz);
				}
				return null;
			}
		};
		return query(sql, rsh, params);
	}

	/**
	 * execute SQL, transform ResultSet to Class<T>[List<Bean>]
	 * 
	 * @param sql
	 *            query SQL
	 * @param clazz
	 *            target class
	 * @return
	 * @throws SQLException
	 */
	public <T> List<T> queryBeanList(String sql, final Class<T> clazz)
			throws SQLException {
		return queryBeanList(sql, clazz, new HashMap<String, String>(),
				(Object[]) null);
	}

	/**
	 * execute SQL, transform ResultSet to Class<T>[List<Bean>]
	 * 
	 * @param params
	 *            SQL PARAMS
	 * @return
	 * @throws SQLException
	 */
	public <T> List<T> queryBeanList(String sql, final Class<T> clazz,
			Object... params) throws SQLException {
		return queryBeanList(sql, clazz, new HashMap<String, String>(), params);
	}

	/**
	 * execute SQL, transform ResultSet to Class<T>[List<Bean>]
	 * 
	 * @param columnToPropertyOverrides
	 *            column to property overrides
	 * @return
	 * @throws SQLException
	 */
	public <T> List<T> queryBeanList(String sql, final Class<T> clazz,
			final Map<String, String> columnToPropertyOverrides,
			Object... params) throws SQLException {
		ResultSetHandler<List<T>> rsh = new ResultSetHandler<List<T>>() {
			@Override
			public List<T> handle(ResultSet rs) throws SQLException {
				BeanProcessor bp = new BeanProcessor(columnToPropertyOverrides);
				return bp.toBeanList(rs, clazz);
			}

		};
		return query(sql, rsh, params);
	}

	/**
	 * execute SQL, transform ResultSet to Class<T>[Map<String,<Bean>>]
	 * 
	 * @param sql
	 * @param clazz
	 * @param columnName
	 * @return
	 * @throws SQLException
	 */
	public <T> Map<String, T> queryBeanMap(String sql, final Class<T> clazz,
			String columnName) throws SQLException {
		return queryBeanMap(sql, clazz, columnName,
				new HashMap<String, String>(), (Object[]) null);
	}

	/**
	 * execute SQL, transform ResultSet to Class<T>[Map<String,<Bean>>]
	 * 
	 * @param sql
	 * @param clazz
	 * @param columnName
	 * @return
	 * @throws SQLException
	 */
	public <T> Map<String, T> queryBeanMap(String sql, final Class<T> clazz,
			String columnName, Object... params) throws SQLException {
		return queryBeanMap(sql, clazz, columnName,
				new HashMap<String, String>(), params);
	}

	/**
	 * execute SQL, transform ResultSet to Class<T>[Map<String,<Bean>>]
	 * 
	 * @param sql
	 * @param clazz
	 * @param columnName
	 * @return
	 * @throws SQLException
	 */
	public <T> Map<String, T> queryBeanMap(String sql, final Class<T> clazz,
			final String columnName,
			final Map<String, String> columnToPropertyOverrides,
			Object... params) throws SQLException {
		ResultSetHandler<Map<String, T>> rsh = new ResultSetHandler<Map<String, T>>() {
			BeanProcessor bp = new BeanProcessor(columnToPropertyOverrides);

			@Override
			public Map<String, T> handle(ResultSet rs) throws SQLException {
				Map<String, T> result = new HashMap<String, T>();
				while (rs.next()) {
					result.put(createKey(rs), createRow(rs));
				}
				return result;
			}

			private String createKey(ResultSet rs) throws SQLException {
				return rs.getString(columnName);
			}

			private T createRow(ResultSet rs) throws SQLException {
				return bp.toBean(rs, clazz);
			}
		};
		return query(sql, rsh, params);
	}

	/**
	 * execute SQL, transform ResultSet to Class<T>[Map<String,<Object>>]
	 * 
	 * @param sql
	 * @return
	 * @throws SQLException
	 */
	public <T> Map<String, Object> queryMap(String sql) throws SQLException {
		MapHandler kh = new MapHandler();
		return query(sql, kh);
	}

	/**
	 * execute SQL, transform ResultSet to
	 * Class<T>[Map<Object,Map<String,<Object>>>]
	 * 
	 * @param sql
	 * @param column
	 * @return
	 * @throws SQLException
	 */
	public <T> Map<Object, Map<String, Object>> queryKeyMap(String sql,
			String column) throws SQLException {
		KeyedHandler<Object> kh = new KeyedHandler<Object>(column);
		return query(sql, kh);
	}

	/**
	 * execute SQL, transform ResultSet to Class<T>[List<Map<String,Object>>]
	 * 
	 * @param sql
	 * @return
	 * @throws SQLException
	 */
	public <T> List<Map<String, Object>> queryListMap(String sql)
			throws SQLException {
		MapListHandler kh = new MapListHandler();
		return query(sql, kh);
	}

	/**
	 * execute SQL, transform ResultSet to Class<T>[Object[]]
	 * 
	 * @param sql
	 * @return
	 * @throws SQLException
	 */
	public <T> Object[] queryArray(String sql) throws SQLException {
		ArrayHandler kh = new ArrayHandler();
		return query(sql, kh);
	}

	/**
	 * execute SQL, transform ResultSet to Class<T>[List<Object[]>]
	 * 
	 * @param sql
	 * @return
	 * @throws SQLException
	 */
	public <T> List<Object[]> queryArrayList(String sql) throws SQLException {
		ArrayListHandler kh = new ArrayListHandler();
		return query(sql, kh);
	}

	/**
	 * query column name, return column values
	 * 
	 * @param sql
	 *            query SQL
	 * @param columnName
	 *            column name
	 * @return
	 * @throws SQLException
	 */
	public <T> List<T> queryColumnList(String sql, String columnName)
			throws SQLException {
		return queryColumnList(sql, columnName, (Object[]) null);
	}

	/**
	 * query column name, return column values
	 * 
	 * @param params
	 *            SQL PARAMS
	 * @return
	 * @throws SQLException
	 */
	public <T> List<T> queryColumnList(String sql, String columnName,
			Object... params) throws SQLException {
		ColumnListHandler<T> clh = new ColumnListHandler<T>(columnName);
		return query(sql, clh, params);
	}

	/**
	 * query object, (T)rs.getObject(1), return column value
	 * 
	 * 
	 * @param sql
	 * @param clazz
	 * @return
	 * @throws SQLException
	 */
	public <T> T queryForObject(String sql, Class<T> clazz) throws SQLException {
		return queryForObject(sql, clazz, (Object[]) null);
	}

	/**
	 * query object, (T)rs.getObject(1), return column value
	 * 
	 * 
	 * @param sql
	 * @param clazz
	 * @return
	 * @throws SQLException
	 */
	public <T> T queryForObject(String sql, final Class<T> clazz,
			Object... params) throws SQLException {
		ScalarHandler<T> kh = new ScalarHandler<T>() {
			@SuppressWarnings("unchecked")
			public T handle(ResultSet rs) throws SQLException {
				T target = null;
				Object resultObject = null;
				if (rs.next()) {
					resultObject = rs.getObject(1);
				}
				if (resultObject != null
						&& Number.class.isAssignableFrom(resultObject
								.getClass())) {
					if (BigDecimal.class.isInstance(resultObject)) {
						BigDecimal bd = (BigDecimal) resultObject;
						if (Integer.class.isAssignableFrom(clazz)) {
							target = (T) Integer.valueOf(bd.intValue());
						} else if (Long.class.isAssignableFrom(clazz)) {
							target = (T) Long.valueOf(bd.longValue());
						} else if (Float.class.isAssignableFrom(clazz)) {
							target = (T) Float.valueOf(bd.floatValue());
						} else if (Double.class.isAssignableFrom(clazz)) {
							target = (T) Double.valueOf(bd.doubleValue());
						}
					}
				} else {
					target = (T) resultObject;
				}
				return target;
			}
		};
		return query(sql, kh, params);
	}

	/**
	 * query column name, return column value
	 * 
	 * @param sql
	 *            query SQL
	 * @param columnName
	 *            column name
	 * @return column value
	 * @throws SQLException
	 */
	public <T> T queryColumn(String sql, String columnName) throws SQLException {
		return queryColumn(sql, columnName, (Object[]) null);
	}

	/**
	 * query column name, return column value
	 * 
	 * @param sql
	 *            query SQL
	 * @param columnName
	 *            column name
	 * @return column value
	 * @throws SQLException
	 */
	public <T> T queryColumn(String sql, String columnName, Object... params)
			throws SQLException {
		ScalarHandler<T> kh = new ScalarHandler<T>(columnName);
		return query(sql, kh, params);
	}

	/**
	 * Return whether the given JDBC driver supports JDBC 2.0 batch updates.
	 * <p>
	 * Typically invoked right before execution of a given set of statements: to
	 * decide whether the set of SQL statements should be executed through the
	 * JDBC 2.0 batch mechanism or simply in a traditional one-by-one fashion.
	 * <p>
	 * Logs a warning if the "supportsBatchUpdates" methods throws an exception
	 * and simply returns {@code false} in that case.
	 * 
	 * @param con
	 *            the Connection to check
	 * @return whether JDBC 2.0 batch updates are supported
	 * @see java.sql.DatabaseMetaData#supportsBatchUpdates()
	 */
	private static boolean supportsBatchUpdates(Connection con) {
		try {
			DatabaseMetaData dbmd = con.getMetaData();
			if (dbmd != null) {
				if (dbmd.supportsBatchUpdates()) {
					log.debug("JDBC driver supports batch updates");
					return true;
				} else {
					log.debug("JDBC driver does not support batch updates");
				}
			}
		} catch (SQLException ex) {
			log.debug(
					"JDBC driver 'supportsBatchUpdates' method threw exception",
					ex);
		} catch (AbstractMethodError err) {
			log.debug(
					"JDBC driver does not support JDBC 2.0 'supportsBatchUpdates' method",
					err);
		}
		return false;
	}

	/**
	 * get SQL with sqlKey
	 * 
	 * NOTE: you must be give path in construct
	 * 
	 * @param sqlkey
	 * @return
	 * @throws SQLException
	 */
	public String getSql(String sqlkey) throws SQLException {
		String sql = sqlKeys.get(sqlkey);
		return sql;
	}
	
	/**
	 * via sequnceName to generator SQL
	 * 
	 * @param sequnceName
	 * @return
	 */
	private String getSequnceSql(String sequnceName){
		String sequnceSql = "select " + sequnceName
				+ ".nextval  from dual";
		return sequnceSql;
	}

	/**
	 * load queries from path
	 * 
	 * @param path
	 * @return
	 */
	public Map<String, String> loadQueries(String path) {
		QueryLoader ql = QueryLoader.instance();
		Map<String, String> queries = new HashMap<String, String>();
		try {
			queries = ql.load(path);
		} catch (IOException e) {
			throw new RuntimeException("Load Queries  fail, [" + path + "]");
		}
		return queries;
	}
} 

package com.kneel.core.help;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import junit.framework.TestCase;

import org.apache.commons.dbutils.ResultSetHandler;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class DatabaseHelperTest extends TestCase{
	private static final Log log = LogFactory.getLog(DatabaseHelperTest.class);
	 
	 public void testSinglton(){ 
		 Thread t1 =  new Thread(new Runnable(){ 
			@Override
			public void run() { 
				DatabaseHelper helper1 = new DatabaseHelper();
			}
			  
		  }); 
		 
		 Thread t2 =  new Thread(new Runnable(){ 
			@Override
			public void run() { 
				DatabaseHelper	helper2 = new DatabaseHelper();
			}
				  
		});
		 t1.start();t2.start();
		 System.out.println("a");
	 }
	 
	 public void testQuerySqlRsh(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEventById");
			 Event event = helper.query(sql, new ResultSetHandler<Event>(){ 
				 public Event handle(ResultSet rs) throws SQLException{
					 if(rs.next()){
						 Event event = new Event();
						 event.setId(rs.getLong(1));
						 event.setDate(rs.getDate(2));
						 event.setTitle(rs.getString(3));
						 return event;
					 }
					 return null;
				 }
			 },Long.valueOf(140));
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testUpdateSql(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("updateEvent");
			 Object[] params = new Object[]{new java.sql.Date(new Date().getTime()),"updateEvent Title",Long.valueOf(140)};
			 int effect = helper.update(sql,params);
			 System.out.println(effect);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testBatch(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("updateEvent");
			 Object[][] params = new Object[][]{
					 new Object[]{new java.sql.Date(new Date().getTime()),"updateEvent Title",Long.valueOf(140)},
					 new Object[]{new java.sql.Date(new Date().getTime()),"updateEvent Title",Long.valueOf(165)}		 
			 };
			 int effect[] = helper.batch(sql,params);
			 System.out.println(Arrays.toString(effect));
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testBatchInBatchSize(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("updateEvent");
			 Object[][] params = new Object[][]{
					 new Object[]{new java.sql.Date(new Date().getTime()),"updateEvent Title",Long.valueOf(140)},
					 new Object[]{new java.sql.Date(new Date().getTime()),"updateEvent Title",Long.valueOf(165)},
					 new Object[]{new java.sql.Date(new Date().getTime()),"updateEvent Title",Long.valueOf(162)},
					 new Object[]{new java.sql.Date(new Date().getTime()),"updateEvent Title",Long.valueOf(163)},
					 new Object[]{new java.sql.Date(new Date().getTime()),"updateEvent Title",Long.valueOf(164)}
			 };
			 int effect[] = helper.batch(sql,params,2);
			 System.out.println(Arrays.toString(effect));
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testInsert(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("insertEvent");
			 String sequnceName = helper.getSql("eventsSequnce");
			 Object[] params = new Object[]{new java.sql.Date(new Date().getTime()),"insertEvent Title"};
			 Long id = helper.insert(sql,sequnceName,params);
			 System.out.println(id);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
 
	 public void testInsertBatch(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("insertEvent");
			 String sequnceName = helper.getSql("eventsSequnce");
			 Object[][] params = new Object[][]{
					 new Object[]{new java.sql.Date(new Date().getTime()),"insertEvent Title"},
					 new Object[]{new java.sql.Date(new Date().getTime()),"insertEvent Title"}		 
			 };
			 Long effect[] = helper.insertBatch(sql,sequnceName,params);
			 System.out.println(Arrays.toString(effect));
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testInsertInBatchSize(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("insertEvent");
			 String sequnceName = helper.getSql("eventsSequnce");
			 Object[][] params = new Object[][]{
					 new Object[]{new java.sql.Date(new Date().getTime()),"insertEvent Title"},
					 new Object[]{new java.sql.Date(new Date().getTime()),"insertEvent Title"},
					 new Object[]{new java.sql.Date(new Date().getTime()),"insertEvent Title"},
					 new Object[]{new java.sql.Date(new Date().getTime()),"insertEvent Title"},
					 new Object[]{new java.sql.Date(new Date().getTime()),"insertEvent Title"}
			 };
			 Long effect[] = helper.insertBatch(sql,sequnceName,params,2);
			 System.out.println(Arrays.toString(effect));
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testQueryBean(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEventById");
			 Event event = helper.queryBean(sql, Event.class,Long.valueOf(140)); 
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testQueryBeanByRenameLable(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEventById");
			 sql = "SELECT event_id id,event_date,title FROM events WHERE event_id = ?";
			 Event event = helper.queryBean(sql, Event.class,Long.valueOf(140)); 
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testQueryBeanByRenameMapping(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEventById");
			 Map<String,String> ctp = new HashMap<String,String>();
			 ctp.put("EVENT_ID", "id");
			 ctp.put("EVENT_DATE", "date");
			 Event event = helper.queryBean(sql, Event.class,ctp,Long.valueOf(140)); 
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testQueryBeanList(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEvents");
			 Map<String,String> ctp = new HashMap<String,String>();
			 ctp.put("EVENT_ID", "id");
			 ctp.put("EVENT_DATE", "date");
			 List<Event> event = helper.queryBeanList(sql, Event.class,ctp); 
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testBeanMap(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEvents");
			 Map<String,String> ctp = new HashMap<String,String>();
			 ctp.put("EVENT_ID", "id");
			 ctp.put("EVENT_DATE", "date");
			 Map<String,Event> event = helper.queryBeanMap(sql, Event.class,"EVENT_ID",ctp); 
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testQueryMap(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEvents"); 
			 Map<String,Object> event = helper.queryMap(sql); 
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testQueryKeyMap(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEvents"); 
			Map<Object,Map<String,Object>> event = helper.queryKeyMap(sql, "EVENT_ID"); 
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void testQueryListMap(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEvents"); 
			 List<Map<String,Object>> event = helper.queryListMap(sql); 
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void queryArray(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEvents"); 
			 Object[] event = helper.queryArray(sql); 
			 System.out.println(Arrays.toString(event));
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void queryArrayList(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEvents"); 
			 List<Object[]> event = helper.queryArrayList(sql); 
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void queryColumnList(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEvents"); 
			 List<Object> event = helper.queryColumnList(sql, "EVENT_ID"); 
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void queryForObject(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryCounts"); 
			 Long event = helper.queryForObject(sql,Long.class); 
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
	 
	 public void queryColumn(){
		 DatabaseHelper helper = new DatabaseHelper("/sql/Event.xml");
		 try {
			 String sql = helper.getSql("queryEvents"); 
			 Object event = helper.queryColumn(sql, "EVENT_ID"); 
			 System.out.println(event);
		} catch (SQLException e) {
			log.error("sql error", e);
		}
	 }
}