[原创]通用的面向对象查询的dao(2)
[原创]通用的面向对象查询的dao(二)
dao的改进版,支持简单的注解,例如@DbConfig(length = 20000,type="BLOB"),其中len为字段长度,type为映射到的类型,支持orm查询和其他查询方式。为sqllite数据库写的。
1.数据源类DataSource:
2.自定义注解类DbConfig:
3.行集映射器类Mapper:
4.命名转换器类NameConverter :
5.主类Dao:
dao的改进版,支持简单的注解,例如@DbConfig(length = 20000,type="BLOB"),其中len为字段长度,type为映射到的类型,支持orm查询和其他查询方式。为sqllite数据库写的。
1.数据源类DataSource:
package com.lowca.robot.dao.support; import java.io.PrintWriter; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class DataSource implements javax.sql.DataSource { private static final String DRIVER = "org.sqlite.JDBC"; private static final String CONNECT_URL = "jdbc:sqlite:c:/robot.db"; private static final String USERNAME = null; private static final String PASSWORD = null; private static final Log log = LogFactory.getLog(DataSource.class); static { try { Class.forName(DRIVER); } catch (ClassNotFoundException e) { throw new RuntimeException("加载JDBC驱动失败:\n" + e.getMessage()); } } @Override public Connection getConnection() throws SQLException { Connection conn = DriverManager.getConnection(CONNECT_URL); conn.setAutoCommit(false); return conn; } @Override public Connection getConnection(String username, String password) throws SQLException { Connection conn = DriverManager.getConnection(CONNECT_URL, USERNAME, PASSWORD); conn.setAutoCommit(false); return conn; } @Override public PrintWriter getLogWriter() throws SQLException { // TODO Auto-generated method stub return null; } @Override public int getLoginTimeout() throws SQLException { // TODO Auto-generated method stub return 0; } @Override public void setLogWriter(PrintWriter out) throws SQLException { // TODO Auto-generated method stub } @Override public void setLoginTimeout(int seconds) throws SQLException { // TODO Auto-generated method stub } @Override public boolean isWrapperFor(Class<?> iface) throws SQLException { // TODO Auto-generated method stub return false; } @Override public <T> T unwrap(Class<T> iface) throws SQLException { // TODO Auto-generated method stub return null; } /** * 释放连接 * * @param rs * @param ps * @param conn */ public void free(ResultSet rs, PreparedStatement ps, Connection conn) { try { if (rs != null) rs.close(); } catch (Exception e) { log.error(this, e); } finally { try { if (ps != null) ps.close(); } catch (Exception e) { log.error(this, e); } finally { if (conn != null) { try { conn.close(); } catch (SQLException e) { log.error(this, e); } } } } } }
2.自定义注解类DbConfig:
package com.lowca.robot.dao.support; import java.lang.annotation.Documented; import java.lang.annotation.ElementType; import java.lang.annotation.Inherited; import java.lang.annotation.Retention; import java.lang.annotation.RetentionPolicy; import java.lang.annotation.Target; /** * 用户自定义标签,带有成员变量的DbConfig */ @Documented // 将注释包含在JavaDoc中 @Inherited // 允许子类继承父类中的注释。 @Target(value = { ElementType.METHOD, ElementType.CONSTRUCTOR }) // 标注这个注释使用的范围 @Retention(value = RetentionPolicy.RUNTIME) // 要想使用反射得到注释信息,这个注释必须使用 public @interface DbConfig { /** * 映射到的数据库类型 * * @return */ String type() default "";// 映射到的类型 /** * 字段长度 * * @return */ int length() default 100;// 字段长度 }
3.行集映射器类Mapper:
package com.lowca.robot.dao.support; import java.lang.annotation.Annotation; import java.lang.reflect.Method; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.SQLException; import java.util.Date; public class Mapper { /** * 行集映射 * * @param <T> * @param clazz * @param rs * @return * @throws SQLException */ public static <T> T rowMapping(Class<T> clazz, ResultSet rs) throws SQLException { T t = null; if (rs.next()) { try { t = clazz.newInstance(); } catch (Exception e) { throw new RuntimeException(e); } ResultSetMetaData metadata = rs.getMetaData(); int size = metadata.getColumnCount(); for (int i = 0; i < size; i++) { String columnName = metadata.getColumnLabel(i + 1); Object columnValue = rs.getObject(metadata .getColumnLabel(i + 1)); if (columnValue == null) continue; // 给对象赋值 String propertyName = NameConverter.toJavaCase(columnName); String methodName = "set" + propertyName.substring(0, 1).toUpperCase() + propertyName.substring(1); Method[] methods = clazz.getMethods(); for (Method method : methods) { if (methodName.equals(method.getName())) { try { String propertyTypeName = method .getParameterTypes()[0].getName(); String columnTypeName = columnValue.getClass() .getName(); if (propertyTypeName .equalsIgnoreCase(columnTypeName)) method.invoke(t, columnValue); else { // 转换长整型和日期类型的不适配问题 if ("java.util.Date".equals(propertyTypeName) && "java.lang.Long" .equals(columnTypeName)) method.invoke(t, new Date( (Long) columnValue)); // 转换整型为布尔型 if ("java.lang.Boolean" .equals(propertyTypeName) && "java.lang.Integer" .equals(columnTypeName)) method.invoke(t, columnValue.toString() .equals("0") ? false : true); } } catch (Exception e) { throw new RuntimeException(e); } } } } } return t; } public static String classMapping(Class<?> objectClass, String propertyName, Class<?> propertyClass) { String propertyClassName = propertyClass.getName(); if ("java.lang.Integer".equals(propertyClassName) || "java.lang.Long".equals(propertyClassName) || "java.lang.Character".equals(propertyClassName) || "java.lang.Short".equals(propertyClassName)) return "INTEGER"; if ("java.lang.Float".equals(propertyClassName) || "java.lang.Double".equals(propertyClassName)) return "REAL"; if ("java.util.Date".equals(propertyClassName)) return "DATETIME"; if ("java.lang.Boolean".equals(propertyClassName)) return "TINYINT"; // String类型需要根据长度来做不同的映射 if ("java.lang.String".equals(propertyClassName)) { String methodName = "get" + propertyName.substring(0, 1).toUpperCase() + propertyName.substring(1); String typeName = "VARCHAR"; try { Annotation[] annotations = objectClass.getDeclaredMethod( methodName).getAnnotations(); for (Annotation tag : annotations) { if (tag instanceof DbConfig) { int len = ((DbConfig) tag).length(); if (len > 255) { typeName = "TEXT"; break; } String type = ((DbConfig) tag).type(); return type; } } } catch (Exception e) { throw new RuntimeException(e); } return typeName; } return ""; } }
4.命名转换器类NameConverter :
package com.lowca.robot.dao.support; /** * <p>一个做命名规范转换的支持类</p> * <p>用来实现在java命名规范和数据库命名规范之间的转换</p> * @author konglz * */ public class NameConverter { /** * 数据库命名方式转换成java的命名方式 * * @param s * @return */ public static String toJavaCase(String s) { if (s == null || s.trim().length() == 0) return s; StringBuffer sb = new StringBuffer(); String[] array = s.split("_"); boolean firstTime = true; for (String e : array) { if (e.length() == 0) continue; else if (e.length() == 1) sb.append(!firstTime ? e.toUpperCase() : e); else sb.append(!firstTime ? (e.substring(0, 1).toUpperCase() + e .substring(1)) : e); firstTime = false; } return sb.toString(); } /** * Java命名方式转换成数据库的命名方式 * * @param s * @return */ public static String toDbCase(String s) { if (s == null || s.trim().length() == 0) return s; char[] chars = s.toCharArray(); boolean firstTime = true; StringBuffer sb = new StringBuffer(); for (char c : chars) { if (c >= 'A' && c <= 'Z') { char c1 = (char) (c + 32); sb.append(firstTime ? c1 : "_" + c1); } else sb.append(c); firstTime = false; } return sb.toString(); } public static void main(String[] args) { // System.out // .println(toDbCase("theyBeganToHumWhenSeeingJacksonWalkIntoTheHall")); // System.out // .println(toJavaCase(toDbCase("theyBeganToHumWhenSeeingJacksonWalkIntoTheHall"))); StringBuffer sb = new StringBuffer("sdsdfds1"); sb.delete(sb.length() - 1, sb.length()); System.out.println(sb); } }
5.主类Dao:
package com.lowca.robot.dao; import java.lang.reflect.Method; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.SQLException; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; import com.lowca.robot.dao.support.DataSource; import com.lowca.robot.dao.support.Mapper; import com.lowca.robot.dao.support.NameConverter; /** * <p> * 通用dao类,用法和说明如下: * </p> * <p> * 1.不支持事务 * </p> * <p> * 2.不支持连接池 * </p> * <p> * 3.命名方法必须严格遵守java pojo和数据库的命名规范/p> * <p> * 4.主键必须叫做“id”,且必须为Integer类型,其他基本类型的属性必须为其封装类型 * </p> * <p> * 5.不支持复杂映射 * </p> * * @author kong * */ public class Dao { private final DataSource dataSource = new DataSource(); /** * 查询方法 * * @param <T> * @param clazz * @param sql * @param values * @return * @throws SQLException */ public <T> T query(Class<T> clazz, String sql, Object[] values) throws SQLException { Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); if (values != null) { for (int i = 0; i < values.length; i++) { ps.setObject(i + 1, values[i]); } } ResultSet rs = ps.executeQuery(); T t = Mapper.rowMapping(clazz, rs); dataSource.free(null, ps, conn); return t; } /** * 查询方法(不带参数) * * @param <T> * @param clazz * @param sql * @return * @throws SQLException */ public <T> T query(Class<T> clazz, String sql) throws SQLException { return query(clazz, sql, null); } /** * 查询多个对象 * * @param <T> * @param clazz * @param sql * @param values * @return * @throws SQLException */ public <T> List<T> queryList(Class<T> clazz, String sql, Object[] values) throws SQLException { Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); if (values != null) { for (int i = 0; i < values.length; i++) { ps.setObject(i + 1, values[i]); } } ResultSet rs = ps.executeQuery(); List<T> list = new ArrayList<T>(); T t = null; while ((t = Mapper.rowMapping(clazz, rs)) != null) { list.add(t); } dataSource.free(null, ps, conn); return list; } /** * 查询多个对象(不带参数) * * @param <T> * @param clazz * @param sql * @return * @throws SQLException */ public <T> List<T> queryList(Class<T> clazz, String sql) throws SQLException { return queryList(clazz, sql, null); } /** * 查询某列第一行的值 * * @param sql * @param values * @param columnName * 列名 * @return * @throws SQLException */ public Object queryForObject(String sql, Object[] values, String columnName) throws SQLException { Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); if (values != null) { for (int i = 0; i < values.length; i++) { ps.setObject(i + 1, values[i]); } } ResultSet rs = ps.executeQuery(); Object object = null; if (rs.next()) { object = rs.getObject(columnName); } dataSource.free(null, ps, conn); return object; } /** * 查询某列第一行的值(不带参数) * * @param sql * @param columnName * 列名 * @return * @throws SQLException */ public Object queryForObject(String sql, String columnName) throws SQLException { return queryForObject(sql, null, columnName); } /** * 查询某列所有行的值作为一个数组返回 * * @param sql * @param values * @param columnName * 列名 * @return * @throws SQLException */ public Object[] queryForArray(String sql, Object[] values, String columnName) throws SQLException { Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); if (values != null) { for (int i = 0; i < values.length; i++) { ps.setObject(i + 1, values[i]); } } ResultSet rs = ps.executeQuery(); List<Object> list = new ArrayList<Object>(); while (rs.next()) { list.add(rs.getObject(columnName)); } dataSource.free(null, ps, conn); return list.toArray(); } /** * 查询某列所有值作为一个数组返回(不带参数) * * @param sql * @param columnName * @return * @throws SQLException */ public Object[] queryForArray(String sql, String columnName) throws SQLException { return queryForArray(sql, null, columnName); } /** * 查询所有行所有列的值,作为一个数组的列表返回 * * @param sql * @param values * @return * @throws SQLException */ public List<Object[]> queryForArrayList(String sql, Object[] values) throws SQLException { Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); if (values != null) { for (int i = 0; i < values.length; i++) { ps.setObject(i + 1, values[i]); } } ResultSet rs = ps.executeQuery(); List<Object[]> result = new ArrayList<Object[]>(); List<Object> list = new ArrayList<Object>(); ResultSetMetaData metadata = rs.getMetaData(); while (rs.next()) { int size = metadata.getColumnCount(); for (int i = 0; i < size; i++) { Object columnValue = rs.getObject(metadata .getColumnLabel(i + 1)); list.add(columnValue); } result.add(list.toArray()); } dataSource.free(null, ps, conn); return result; } /** * 查询所有行所有列的值,作为一个数组的列表返回(不带参数) * * @param sql * @return * @throws SQLException */ public List<Object[]> queryForArrayList(String sql) throws SQLException { return queryForArrayList(sql, null); } /** * 查询成一个map * * @param sql * @param values * @return * @throws SQLException */ public Map<String, Object> queryForMap(String sql, Object[] values) throws SQLException { Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); if (values != null) { for (int i = 0; i < values.length; i++) { ps.setObject(i + 1, values[i]); } } ResultSet rs = ps.executeQuery(); Map<String, Object> map = new HashMap<String, Object>(); ResultSetMetaData metadata = rs.getMetaData(); if (rs.next()) { int size = metadata.getColumnCount(); for (int i = 0; i < size; i++) { String columnName = metadata.getColumnLabel(i + 1); Object columnValue = rs.getObject(metadata .getColumnLabel(i + 1)); map.put(columnName, columnValue); } } dataSource.free(null, ps, conn); return map; } /** * 查询成一个map(不带参数) * * @param sql * @return * @throws SQLException */ public Map<String, Object> queryForMap(String sql) throws SQLException { return queryForMap(sql, null); } /** * 查询成一个map的列表 * * @param sql * @param values * @return * @throws SQLException */ public List<Map<String, Object>> queryForMapList(String sql, Object[] values) throws SQLException { Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); if (values != null) { for (int i = 0; i < values.length; i++) { ps.setObject(i + 1, values[i]); } } ResultSet rs = ps.executeQuery(); List<Map<String, Object>> list = new ArrayList<Map<String, Object>>(); Map<String, Object> map = new HashMap<String, Object>(); ResultSetMetaData metadata = rs.getMetaData(); if (rs.next()) { int size = metadata.getColumnCount(); for (int i = 0; i < size; i++) { String columnName = metadata.getColumnLabel(i + 1); Object columnValue = rs.getObject(metadata .getColumnLabel(i + 1)); map.put(columnName, columnValue); } list.add(map); } dataSource.free(null, ps, conn); return list; } /** * 查询成一个map的列表(不带参数) * * @param sql * @return * @throws SQLException */ public List<Map<String, Object>> queryForMapList(String sql) throws SQLException { return queryForMapList(sql, null); } /** *统计一类对象的个数 * * @param clazz * @return * @throws SQLException */ public int count(Class<?> clazz) throws SQLException { Connection conn = dataSource.getConnection(); String tableName = NameConverter.toDbCase(clazz.getSimpleName()); String sql = "SELECT COUNT(id) FROM " + tableName; PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); int num = 0; if (rs.next()) num = rs.getInt(1); dataSource.free(null, ps, conn); return num; } /** * 根据sql统计 * * @param sql * @param values * @return * @throws SQLException */ public int count(String sql, Object[] values) throws SQLException { Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); if (values != null) { for (int i = 0; i < values.length; i++) { ps.setObject(i + 1, values[i]); } } ResultSet rs = ps.executeQuery(); int num = 0; if (rs.next()) num = rs.getInt(1); dataSource.free(null, ps, conn); return num; } /** * 根据sql统计(不带参数) * * @param sql * @return * @throws SQLException */ public int count(String sql) throws SQLException { return count(sql, null); } /** * 根据id获取 * * @param <T> * @param clazz * @param id * @return * @throws SQLException */ public <T> T get(Class<T> clazz, Integer id) throws SQLException { String tableName = NameConverter.toDbCase(clazz.getSimpleName()); String sql = "SELECT * FROM " + tableName + " WHERE id=" + id.intValue(); Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); ResultSet rs = ps.executeQuery(); T t = Mapper.rowMapping(clazz, rs); dataSource.free(null, ps, conn); return t; } /** * 删除对象 * * @param clazz * @param id * @return * @throws SQLException */ public int delete(Class<?> clazz, Integer id) throws SQLException { String tableName = NameConverter.toDbCase(clazz.getSimpleName()); String sql = "DELETE FROM " + tableName + " WHERE id=" + id.intValue(); Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); int rowCount = ps.executeUpdate(); dataSource.free(null, ps, conn); return rowCount; } /** * 保存对象 * * @param object * @throws SQLException */ public void save(Object object) throws SQLException { // 通过反射提取属性和属性值 Method[] methods = object.getClass().getMethods(); Map<String, Object> kvMap = new HashMap<String, Object>(); for (Method method : methods) { if (method.getName().startsWith("set")) { String key = method.getName().substring(3, 4).toLowerCase() + method.getName().substring(4); Method getMethod = null; Object value = null; try { getMethod = object.getClass().getDeclaredMethod( method.getName().replaceFirst("set", "get")); value = getMethod.invoke(object); } catch (Exception e) { throw new RuntimeException(e); } kvMap.put(key, value); } } // 生成sql String tableName = NameConverter.toDbCase(object.getClass() .getSimpleName()); Object[] values = new Object[kvMap.size()]; StringBuffer sb = new StringBuffer("INSERT INTO " + tableName + "("); StringBuffer params = new StringBuffer(); int index = 0; for (String key : kvMap.keySet()) { String columnName = NameConverter.toDbCase(key); sb.append(columnName + ","); params.append("?,"); values[index] = kvMap.get(key); index++; } if (sb.charAt(sb.length() - 1) == ',') sb.delete(sb.length() - 1, sb.length()); if (params.charAt(params.length() - 1) == ',') params.delete(params.length() - 1, params.length()); sb.append(") VALUES(").append(params).append(");"); String sql = sb.toString(); // 执行sql Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); if (values != null) { for (int i = 0; i < values.length; i++) { ps.setObject(i + 1, values[i]); } } conn.setAutoCommit(true); ps.execute(); conn.setAutoCommit(false); // 获取主键 ps = conn.prepareStatement("SELECT LAST_INSERT_ROWID()"); ResultSet rs = ps.executeQuery(); Integer pk = 0; if (rs.next()) pk = rs.getInt(1); // 给对象赋主键的值 try { Method method = object.getClass().getDeclaredMethod("setId", Integer.class); method.invoke(object, pk); } catch (Exception e) { throw new RuntimeException(e); } dataSource.free(null, ps, conn); } /** * 更新对象 * * @param object * @throws SQLException */ public void update(Object object) throws SQLException { // 通过反射提取属性和属性值 Method[] methods = object.getClass().getMethods(); Map<String, Object> kvMap = new HashMap<String, Object>(); for (Method method : methods) { if (method.getName().startsWith("set")) { String key = method.getName().substring(3, 4).toLowerCase() + method.getName().substring(4); Method getMethod = null; Object value = null; try { getMethod = object.getClass().getDeclaredMethod( method.getName().replaceFirst("set", "get")); value = getMethod.invoke(object); } catch (Exception e) { throw new RuntimeException(e); } kvMap.put(key, value); } } // 生成sql String tableName = NameConverter.toDbCase(object.getClass() .getSimpleName()); Object[] values = new Object[kvMap.size()]; StringBuffer sb = new StringBuffer("UPDATE " + tableName + " "); int index = 0; Integer id = 0; boolean firstTime = true; for (String key : kvMap.keySet()) { String columnName = NameConverter.toDbCase(key); if (key.equalsIgnoreCase("id")) { id = (Integer) kvMap.get(key); continue; } sb.append((firstTime ? " SET " : "") + columnName + "=?,"); firstTime = false; values[index] = kvMap.get(key); index++; } values[index] = id; if (sb.charAt(sb.length() - 1) == ',') sb.delete(sb.length() - 1, sb.length()); sb.append(" WHERE id=?;"); String sql = sb.toString(); // 执行sql Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); if (values != null) { for (int i = 0; i < values.length; i++) { ps.setObject(i + 1, values[i]); } } conn.setAutoCommit(true); ps.executeUpdate(); conn.setAutoCommit(false); dataSource.free(null, ps, conn); } /** * 执行sql语句 * * @param sql * @param values * @return * @throws SQLException */ public boolean execute(String sql, Object[] values) throws SQLException { Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); if (values != null) { for (int i = 0; i < values.length; i++) { ps.setObject(i + 1, values[i]); } } conn.setAutoCommit(true); boolean r = ps.execute(); conn.setAutoCommit(false); dataSource.free(null, ps, conn); return r; } /** * 执行sql语句,不带参数 * * @param sql * @return * @throws SQLException */ public boolean execute(String sql) throws SQLException { return execute(sql, null); } /** * 检查数据库是否有这个表 * * @param clazz * @return * @throws SQLException */ public boolean existTable(Class<?> clazz) throws SQLException { String tableName = NameConverter.toDbCase(clazz.getSimpleName()); String sql = "SELECT COUNT(*) AS table_count FROM sqlite_master WHERE TYPE='table' AND NAME=?;"; Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); ps.setObject(1, tableName); ResultSet rs = ps.executeQuery(); int num = 0; if (rs.next()) { num = rs.getInt("table_count"); } dataSource.free(null, ps, conn); return num > 0 ? true : false; } /** * 使用类来创建表 * * @param clazz * @param delIfExist * 如果表已存在,true表示删除旧表并重新建表,false表示保留旧表不再重新建 * @throws SQLException */ public void createTable(Class<?> clazz, boolean delIfExist) throws SQLException { // 如果表已经存在,则看看是否需要删除 boolean existTable = existTable(clazz); if (!delIfExist && existTable) { return; } if (delIfExist && existTable) { deleteTable(clazz); } // 通过反射提取属性和属性值 Method[] methods = clazz.getMethods(); Map<String, Class<?>> kvMap = new HashMap<String, Class<?>>(); for (Method method : methods) { if (method.getName().startsWith("set")) { String property = method.getName().substring(3, 4) .toLowerCase() + method.getName().substring(4); Class<?> propertyClass = method.getParameterTypes()[0]; kvMap.put(property, propertyClass); } } // 生成sql String tableName = NameConverter.toDbCase(clazz.getSimpleName()); StringBuffer sb = new StringBuffer("CREATE TABLE " + tableName + " (id INTEGER PRIMARY KEY,"); for (String key : kvMap.keySet()) { if (key.equalsIgnoreCase("id")) { continue; } String columnName = NameConverter.toDbCase(key); Class<?> propertyClass = kvMap.get(key); String dbTypeName = Mapper.classMapping(clazz, key, propertyClass); sb.append(columnName + " " + dbTypeName + ","); } if (sb.charAt(sb.length() - 1) == ',') sb.delete(sb.length() - 1, sb.length()); sb.append(");"); String sql = sb.toString(); System.out.println(sql); // 执行sql Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); conn.setAutoCommit(true); ps.execute(); conn.setAutoCommit(false); dataSource.free(null, ps, conn); } /** * 使用sql来建表 * * @param sql * @throws SQLException */ public void createTable(String sql) throws SQLException { // 创建表 Connection conn = dataSource.getConnection(); PreparedStatement ps = conn.prepareStatement(sql); conn.setAutoCommit(true); ps.execute(); conn.setAutoCommit(false); dataSource.free(null, ps, conn); } /** * 创建表,如果表已经存在,则不新建 * * @param clazz * @throws SQLException */ public void createTable(Class<?> clazz) throws SQLException { createTable(clazz, false); } /** * 按类名删除表 * * @param clazz * @throws SQLException */ public void deleteTable(Class<?> clazz) throws SQLException { String tableName = NameConverter.toDbCase(clazz.getSimpleName()); String sql = "DROP TABLE IF EXISTS " + tableName; execute(sql); } /** * 按表名删除表 * * @param tableName * @throws SQLException */ public void deleteTable(String tableName) throws SQLException { String sql = "DROP TABLE IF EXISTS " + tableName; execute(sql); } /** * 删除所有表 * * @throws SQLException */ public int deleteAllTable() throws SQLException { String sql = "SELECT name FROM sqlite_master WHERE TYPE='table';"; Object[] objects = queryForArray(sql, "name"); int size = objects.length; for (Object o : objects) deleteTable(o.toString()); return size; } }