设计模式课程 设计模式精讲 10-2 外观模式源码解析

/**
     * Close the given JDBC Connection and ignore any thrown exception.
     * This is useful for typical finally blocks in manual JDBC code.
     * @param con the JDBC Connection to close (may be {@code null})
     */
    public static void closeConnection(Connection con) {
        if (con != null) {
            try {
                con.close();
            }
            catch (SQLException ex) {
                logger.debug("Could not close JDBC Connection",ex);
            }
            catch (Throwable ex) {
                // We don‘t trust the JDBC driver: It might throw RuntimeException or Error.
                logger.debug("Unexpected exception on closing JDBC Connection",ex);
            }
        }
    }

    /**
     * Close the given JDBC Statement and ignore any thrown exception.
     * This is useful for typical finally blocks in manual JDBC code.
     * @param stmt the JDBC Statement to close (may be {@code null})
     */
    public static void closeStatement(Statement stmt) {
        if (stmt != null) {
            try {
                stmt.close();
            }
            catch (SQLException ex) {
                logger.trace("Could not close JDBC Statement",ex);
            }
            catch (Throwable ex) {
                // We don‘t trust the JDBC driver: It might throw RuntimeException or Error.
                logger.trace("Unexpected exception on closing JDBC Statement",ex);
            }
        }
    }

    /**
     * Close the given JDBC ResultSet and ignore any thrown exception.
     * This is useful for typical finally blocks in manual JDBC code.
     * @param rs the JDBC ResultSet to close (may be {@code null})
     */
    public static void closeResultSet(ResultSet rs) {
        if (rs != null) {
            try {
                rs.close();
            }
            catch (SQLException ex) {
                logger.trace("Could not close JDBC ResultSet",ex);
            }
            catch (Throwable ex) {
                // We don‘t trust the JDBC driver: It might throw RuntimeException or Error.
                logger.trace("Unexpected exception on closing JDBC ResultSet",ex);
            }
        }
    }

public MetaObject newMetaObject(Object object) {
    return MetaObject.forObject(object,objectFactory,objectWrapperFactory,reflectorFactory);
  }

  public ParameterHandler newParameterHandler(MappedStatement mappedStatement,Object parameterObject,BoundSql boundSql) {
    ParameterHandler parameterHandler = mappedStatement.getLang().createParameterHandler(mappedStatement,parameterObject,boundSql);
    parameterHandler = (ParameterHandler) interceptorChain.pluginAll(parameterHandler);
    return parameterHandler;
  }

  public ResultSetHandler newResultSetHandler(Executor executor,MappedStatement mappedStatement,RowBounds rowBounds,ParameterHandler parameterHandler,ResultHandler resultHandler,BoundSql boundSql) {
    ResultSetHandler resultSetHandler = new DefaultResultSetHandler(executor,mappedStatement,parameterHandler,resultHandler,boundSql,rowBounds);
    resultSetHandler = (ResultSetHandler) interceptorChain.pluginAll(resultSetHandler);
    return resultSetHandler;
  }