为什么执行的时候总是有例外?
import java.util.*;
import java.sql.*;
public class select
{
Hashtable records[];
int columns=0;
int current=0;
int max=0;
Connection con;
String sql;
public select(Connection con, String sql){//构造方法
int index=0;
this.con=con;
this.sql=sql;
try{
Statement stmt=this.con.createStatement();
ResultSet rs=stmt.executeQuery(this.sql);
ResultSetMetaData md=rs.getMetaData();
this.columns=md.getColumnCount();
Hashtable records[]=new Hashtable[this.columns];
while(rs.next()){
index++;
for(int i=0;i<columns;i++){
if(index==1){
records[i]=new Hashtable();
}
records[i].put(new Integer(index),rs.getString(i+1));
System.out.println(rs.getString(i+1));
}
}
max=index;
}catch(SQLException e){
//max=-1;
}
}
public String getItem(int row,int column){
System.out.println(max);
if ((row<1)||(row>max)){
return "错了";
}
if ((column<1)||(column>this.columns)){
return "嘿嘿 ";
}
return(String)records[column-1].get(new Integer(row));
}
}
我在调用select.getItem(int ,int)的时候,总是出错,
原因是在select的构造方法里,捕捉了例外,从例外里跳出来了.