各位高手，我这三个方法为什么输出后，有的为0呢？其实代码一点都不多，我写的挺规整的……主要看几行代码就行了
在jsp里面的相关代码如下：
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
String stype=request.getParameter("booktype");
int booktype=Integer.parseInt(stype);
int pagenow=1;
int pagesize=6;
GoodsBeanBo gbb=new GoodsBeanBo();
int rowcount=gbb.getrowCount(booktype);
ArrayList al=gbb.getBook(booktype,pagenow);
int pagecount=gbb.getpageCount(rowcount,pagesize);
int size=al.size();
%>
<body>
<%= rowcount%>
<%= pagecount%>
<%=size %>
</body>
可是为什么输出的size为0呢？
后台说错误在public ArrayList getBook方法的这一行：st=ct.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
可是这一行能有什么错误呢？请指点！！谢谢 高分！
java的相关代码如下：各位大侠，帮忙看看，代码很规整没大家想想的那么麻烦……
public class GoodsBeanBo {
Connection ct=new ConnDb().getConn();
ResultSet rs=null;
Statement st=null;
public int getrowCount(int booktype){
int rowcount=0;
try{
st=ct.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
rs=st.executeQuery("select count(*) from goods where goodstype="+booktype);
if(rs.next()){
rowcount=rs.getInt(1);
}else{
rowcount=0;
}
}catch (Exception e){
e.printStackTrace();
}finally{
this.close();
}
return rowcount;
}
//得到总页数pagecount
public int getpageCount(int rowcount,int pagesize ){
int pagecount=0;
try {
if(rowcount%pagesize==0){
pagecount=rowcount/pagesize;
}else{
pagecount=(rowcount/pagesize)+1;
}
}catch (Exception e){
e.printStackTrace();
}finally{
this.close();
}
return pagecount;
}
//得到某页的信息
public ArrayList getBook(int booktype,int pagenow){
ArrayList al=new ArrayList();
try {
st=ct.createStatement(ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
rs=st.executeQuery("select * from goods where goodstype="+booktype+" LIMIT "+(pagenow-1)*6+","+6);
while(rs.next()){
GoodsBean gb=new GoodsBean();
gb.setGoodsid(rs.getInt("goodsid"));
gb.setGoodsname(rs.getString("goodsname"));
gb.setGoodsinfo(rs.getString("goodsinfo"));
gb.setGoodsprice(rs.getString("goodsprice"));
gb.setGoodsnum(rs.getInt("goodsnum"));
gb.setPublisher(rs.getString("publisher"));
gb.setGoodstype(rs.getInt("goodstype"));
gb.setGoodsphoto(rs.getString("goodsphoto"));
gb.setGoodsauthor(rs.getString("goodsauthor"));
al.add(gb);
}
} catch (Exception e) {
e.printStackTrace();
}finally{
this.close();
}
return al;
}
------解决方案--------------------
应该是Connection ct 连接对象的问题
如果先执行这个没问题
int rowcount=gbb.getrowCount(booktype);
然后 有代码
finally{
this.close();
}
是关闭ct连接的意思吗？
再到
ArrayList al=gbb.getBook(booktype,pagenow);
的时候
ct为空或已关闭
createStatement自然会报错
以上都是猜测
没看到楼主 的this.close();怎么定义的
楼主 最好把异常的错误发上来
------解决方案--------------------
