Java定义了一个价格区间查询，jsp页面输出不了结果怎么解决呢

这是BookSaleImpl里getBookSaleByPriceRange方法的代码



   @Override
       public  ArrayList<BookSale> getBookSaleByPriceRange(int minPrice, int maxPrice, String priceRange) {
    ArrayList<BookSale> bookSales = new ArrayList<>();
    Connection conn = Connect.getConn();
    Statement stat = null;
    try {
        stat = conn.createStatement();
        String range = "";
        if (priceRange != null && !priceRange.isEmpty()) {
            // 若传入参数，根据参数设置查询价格区间
            String[] rangeStr = priceRange.split("-");
            if (rangeStr.length == 2) {
                int min = Integer.parseInt(rangeStr[0]);
                int max = Integer.parseInt(rangeStr[1]);
                range = " AND price >= " + min + " AND price < " + max;
            }
        }
        String sqlstr = "SELECT * FROM bookSales WHERE price >= " + minPrice + " AND price < " + maxPrice + range;
        ResultSet rs = stat.executeQuery(sqlstr);
        while (rs.next()) {
            int id = rs.getInt("id");
            int bookId = rs.getInt("bookId");
            int price = rs.getInt("price");
            int quantity = rs.getInt("quantity");
            Date saleDate = rs.getDate("saleDate");
            String dateStr = saleDate.toString();
            BookSale temp = new BookSale(id, bookId, price, quantity, dateStr);
            bookSales.add(temp);
        }
    } catch (Exception e) {
        System.out.println(e.getMessage());
    }
    Connect.getClose(conn, stat);
    return bookSales;
}

Jsp页面的代码：

<%-- 
    Document   : bookModInfo
    Created on : 2023-6-12, 22:33:29
    Author     : 人间惊鸿客
--%>
<%@page import="impl.BookSaleImpl"%>
<%@page import="dao.BookSaleDao"%>
<%@page contentType="text/html" pageEncoding="UTF-8"%>
<!DOCTYPE html>
<%@page import="java.util.ArrayList"%>
<%@page import="vo.BookSale"%>

<html>
<head>
    <meta charset="UTF-8">
    <title>图书价格区间查询</title>
</head>
<body>
<h1>查询图书价格区间</h1>
<form method="post" action="query">
    <p>价格区间：（0，50）<input type="radio" name="priceRange" value="0,50"> （50，100）<input type="radio" name="priceRange" value="50,100"> （100，∞）<input type="radio" name="priceRange" value="100,"> <input type="submit" value="查询"></p>
</form>

<%
    // 获取查询结果
    String priceRange = request.getParameter("priceRange");
    BookSaleDao bookSaleDao = new BookSaleImpl();
    int minPrice = 0;
    int maxPrice = 0;
    ArrayList<BookSale> bookSales = new ArrayList<BookSale>();
    if (priceRange != null) {
        String[] priceArr = priceRange.split(",");
        if (priceArr.length == 2) {
            try {
                minPrice = Integer.parseInt(priceArr[0]);
                maxPrice = Integer.parseInt(priceArr[1]);
            } catch (NumberFormatException e) {
                e.printStackTrace();
            }
        } else if (priceArr.length == 1) {
            try {
                minPrice = Integer.parseInt(priceArr[0]);
            } catch (NumberFormatException e) {
                e.printStackTrace();
            }
        }
        bookSales = bookSaleDao.getBookSaleByPriceRange(minPrice, maxPrice,priceRange);
    }
%>

<%
    // 调试信息
    out.println("priceRange: " + priceRange);
    out.println("bookSales size: " + bookSales.size());
%>

<h2>查询结果：</h2>
<table>
    <tr>
        <th>ID</th>
        <th>图书ID</th>
        <th>价格</th>
        <th>数量</th>
        <th>销售日期</th>
    </tr>
    <% if (!bookSales.isEmpty()) {
          for(BookSale bookSale: bookSales) { %>
            <tr>
                <td><%=bookSale.getId()%></td>
                <td><%=bookSale.getBookId()%></td>
                <td><%=bookSale.getPrice()%></td>
                <td><%=bookSale.getQuantity()%></td>
                <td><%=bookSale.getSaleDate()%></td>
            </tr>
    <%   }
       } else { %>
            <tr>
                <td colspan="5">未查询到符合条件的图书销售记录</td>
            </tr>
    <% } %>
</table>
 

</body>
</html>

这不是没查到数据么，你把你的sql复职出来去数据库带进你的参数去查询，查一下，肯定没符合条件的数据
SELECT * FROM bookSales WHERE price >= " + minPrice + " AND price < " + maxPrice + range;

priceRange为null,没有勾选priceRange，minPrice、maxPrice也是null，可以定义一个默认选中；或者定义默认minPrice、maxPrice