是什么导致“无效光标状态”错误？

Question

运行此代码时出现“无效光标状态”错误。

我使用此代码从Access数据库中获取结果集，然后将其存储在表中。

的代码这部分是只从结果集中获取数据：

data=new Object[numberOfRows][numberOfColumns]; 
for(int i=0;i<numberOfRows;i++){ 
    int j=0; 
    while(j<numberOfColumns){ 
    // int colType=rsmd.getColumnType(j+1); 
    // System.out.println(colType); 
    data[i][j]=rs.getInt("course_id"); 
    System.out.print("0th: "+data[i][j]+" "); 
    j++; 
    data[i][j]=rs.getString("course_name"); 
    System.out.print("1st:"+data[i][j]+" "); 
    j++; 
    data[i][j]=rs.getString("course_date"); 
    System.out.print("2nd:"+data[i][j]+" "); 
    j++; 
    data[i][j]=rs.getString("course_number"); 
    System.out.print("3rd: "+data[i][j]+" "); 
    j++; 
    System.out.print("j:"+j); 
    } 
    System.out.print("Done line:"+i); 
} 

Answer 1

我认为主要的问题是，你永远叫rs.next()滚动光标。但是，根据您对记录结构的说明，您的while循环看起来也是混乱的。尝试以下操作：

data=new Object[numberOfRows][numberOfColumns]; 
for(int i=0;i<numberOfRows;i++) { 
    if (!rs.next()) 
    throw new IllegalStateException(); 
    int j=0; 
    // int colType=rsmd.getColumnType(j+1); 
    // System.out.println(colType); 
    data[i][j]=rs.getInt("course_id"); 
    System.out.print("0th: "+data[i][j++]+" "); 
    data[i][j]=rs.getString("course_name"); 
    System.out.print("1st:"+data[i][j++]+" "); 
    data[i][j]=rs.getString("course_date"); 
    System.out.print("2nd:"+data[i][j++]+" "); 
    data[i][j]=rs.getString("course_number"); 
    System.out.print("3rd: "+data[i][j++]+" "); 
    while(j<numberOfColumns) { 
    data[i][j]=rs.getString(j + 1); 
    System.out.print(j+"th: "+data[i][j++]+" "); 
    } 
    System.out.println(); 
    System.out.println("Done line:"+i); 
}