Java中获取刚插入数据库中的数据Id（主键，自动增长）

public int insert(String cName,String ebrand,String cGender) {
		String sql = "insert into Cloth (cname,ebrand,cgender) values(?,?,?) ";
		Connection conn = DruidUtil.getConn();
		PreparedStatement prep = null;
		ResultSet rs = null ;
		try {
			prep = conn.prepareStatement(sql,PreparedStatement.RETURN_GENERATED_KEYS);
			prep.setString(1,cName);
			prep.setString(2,ebrand);
			prep.setString(3,cGender);
            prep.executeUpdate();
            rs = prep.getGeneratedKeys();
            if (rs.next()) {
            //获取插入数据的Id(主键，自增长)
            int cId = rs.getInt(1) ;
            // 返回这个Id
                return cId ;
            }
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException(e);
        } finally {
        	 DruidUtil.close(conn,prep,rs);
        }
		return -1;
     
    }

prep = conn.prepareStatement(sql,cGender);
            prep.executeUpdate();
            rs = prep.getGeneratedKeys();
            if (rs.next()) {
            //获取插入数据的Id(主键，自增长)
            int cId = rs.getInt(1) ;
            // 返回这个Id
                return cId ;
            }