JDBC中插入数据同时得到主键

String sql = "insert into article values (null, 0, ?, ?, ?, now(), 0)";  
PreparedStatement pstmt = conn.prepareStatement(sql, Statement.RETURN_GENERATED_KEYS);  
 
conn.setAutoCommit(false);  
pstmt.setInt(1, -1);  
pstmt.setString(2, title);  
pstmt.setString(3, content);  
pstmt.executeUpdate();  
 
ResultSet rsKey = pstmt.getGeneratedKeys();  
rsKey.next();  
int key = rsKey.getInt(1);  
rsKey.close();  
 
stmt.executeUpdate("update article set rootid="+key+" where id="+key);  
conn.commit();  
conn.setAutoCommit(true);