ResultSet连续通过Statement赋值,会出现错误
错误提示:jdbc Operation not allowed after ResultSet closed
1 public Task[] getTaskInfo(String a_id){ 2 Task[] task = null; 3 Connection conn = null; 4 Statement stmt = null; 5 ResultSet rs1 = null; 6 ResultSet rs2 = null; 7 try{ 8 Class.forName("com.mysql.jdbc.Driver"); 9 conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/p_note","root","root"); 10 stmt = conn.createStatement(); 11 String sql = "select count(*) from tasks"; 12 String sql2 = "select * from tasks" ; 13 rs1 = stmt.executeQuery(sql); 14 rs2 = stmt.executeQuery(sql2); 15 int count = 0; 16 while(rs1.next()){ 17 count = rs1.getInt(1); 18 } 19 task = new Task[count]; 20 int i=0; 21 while(rs2.next()){ 22 task[i] = new Task(); 23 task[i].setA_id(a_id); 24 task[i].setT_id(rs2.getString("t_id")); 25 task[i].setExecuteTime("t_time"); 26 task[i].setExecuteSite(rs2.getString("t_site")); 27 task[i].setItemName(rs2.getString("t_items")); 28 task[i].setSetout(rs2.getString("t_setout")); 29 task[i].setT_createTime(rs2.getString("t_createTime")); 30 task[i].setT_stamp(rs2.getString("t_stamp")); 31 task[i].setT_stick(rs2.getString("t_stick")); 32 i++; 33 } 34 35 }catch(Exception ex){ 36 ex.printStackTrace(); 37 38 }finally{ 39 try{ 40 if(conn != null){ 41 conn.close(); 42 } 43 if(stmt != null){ 44 stmt.close(); 45 } 46 if(rs1 != null){ 47 rs1.close(); 48 } 49 if(rs2 != null){ 50 rs2.close(); 51 } 52 }catch(Exception ex){ 53 ex.printStackTrace(); 54 } 55 } 56 57 return task; 58 }
红色标记部分会出现错误
原因:数据库提供的方法中,当再次用相同的Statement对ResultSet赋值时,会有个判断 if(ReslutSet != null) {}.在这个方法里面,rs1会被关掉。所以就存在了以上的问题。jdbc Operation not allowed after ResultSet closed
时间: 2024-10-29 19:07:24