jsp跳转servlet实现添加数据

Question

在添加数据的时候总显示添加失败不知道为什么
这是servlet的

protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // TODO Auto-generated method stub    
         
        request.setCharacterEncoding("utf-8");
        String id = request.getParameter("id");
        String name = request.getParameter("name");
        //int price = Integer.parseInt(request.getParameter("price"));
         
        String priceParam = request.getParameter("price");
        int price = 0; // 默认值或错误情况下的处理值
        try {
            if (priceParam != null && !priceParam.isEmpty()) {
                price  = Integer.parseInt(priceParam);
            }
        } catch (NumberFormatException e) {
            
        }
        String kind = request.getParameter("kind");
        String provider = request.getParameter("provider");
        String numParam = request.getParameter("num");
        int num = 0; // 默认值或错误情况下的处理值
        try {
            if (numParam != null && !numParam.isEmpty()) {
                num = Integer.parseInt(numParam);
            }
        } catch (NumberFormatException e) {
            // 处理无法解析为整数的情况，例如给出默认值或错误提示
            // num = 默认值;
            // 输出错误信息或返回给前端的错误提示
        }
     
        Goods goods= new Goods();
        goods.setId(id);
        goods.setName(name);
        goods.setPrice(price);
        goods.setKind(kind);
        goods.setProvider(provider);
        goods.setNum(num);
         
         
        int result = 0;
        try {
            result = dao.Add(goods);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
         
        if ( result ==1) {
            request.setAttribute("message", "添加成功");
            request.getRequestDispatcher("AdminView.jsp").forward(request, response);
        } else {
            request.setAttribute("message", "添加失败");
            request.getRequestDispatcher("AdminAdd.jsp").forward(request, response);
        }

    }
 

这是dao层的添加数据方法

```java

public int Add(Goods goods) throws Exception {
    int i = 0;
    Connection con = null;
    PreparedStatement st = null;
    ResultSet rs = null;
    try {
        con = CnUtil.GetCon();
        String sql = "insert into goods(id,name,price,kind,provider,num) values(?,?,?,?,?,?)";
        st = con.prepareStatement(sql);
        st.setString(1, goods.getId());
        st.setString(2, goods.getName());
        st.setInt(3, goods.getPrice());
        st.setString(4, goods.getKind());
        st.setString(5, goods.getProvider());
        st.setInt(5, goods.getNum());
        i = st.executeUpdate();
    } catch (SQLException e) {
        e.printStackTrace();
    } finally {
        CnUtil.closeResource(con, st, rs);
    }
    return i;
}

```

Answer 1

在这个地方写个输出goods.toString()看看你新增的数据goods内部各个属性具体是什么样的，尤其注意一下属性id的值，看看是不是和数据库中的id重复了，如果id在数据库中是主键那估计插入不进去呢，就先输出看看，查看这个初步的问题是什么，还有可能是你这个id如果是自增那就id对应的sql语句的？可以改成null试试,程序是个精细活，实在不会我帮你远程教你解决这问题