日期:2014-05-18  浏览次数:20805 次

java.lang.NumberFormatException,仿BBS小程序出错,进来帮忙看看。。
文件一:
ShowAtricltTree.jsp
Java code

<%@ page language="java" contentType="text/html; charset=gbk"
    pageEncoding="gbk"%>
<%@ page import="java.sql.*"%>

<%!
String str = "";

    private void tree(Connection conn, int id, int level) {
        Statement stmt = null;
        ResultSet rs = null;
        String preStr = "";
        for (int i = 0; i < level; i++) {
            preStr += "----";
        }
        try {
            stmt = conn.createStatement();
            String sql = "select * from article where pid = " + id;
            rs = stmt.executeQuery(sql);
            while (rs.next())  {
                str += "<tr><td>" + rs.getInt("id") + "</td><td>" + 
                preStr+ "<a href='ShowArticleDetail.jsp?ID="+
                        rs.getInt("id") + "'>" +  rs.getString("title") + "</a>" + 
                        "</td></tr>";
                if (rs.getInt("isleaf") != 0) {
                    tree(conn, rs.getInt("id"), level + 1);
                }

            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (rs != null) {
                    rs.close();
                    rs = null;
                }
                if (stmt != null) {
                    stmt.close();
                    stmt = null;

                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }%>


<%
    Class.forName("com.mysql.jdbc.Driver");
    String url = "jdbc:mysql://localhost/bbs?user=root&password=root";
    Connection conn = DriverManager.getConnection(url);
    Statement stmt = conn.createStatement();
    ResultSet rs = stmt
            .executeQuery("select * from article where pid =0");
    while (rs.next()) {
        str += "<tr><td>" + rs.getInt("id") + "</td><td>" +
        "<a href='ShowArticleDetail.jsp?ID="+rs.getInt("id") + "'>" + 
                rs.getString("title") + "</a>" + "</td></tr>";
        if (rs.getInt("isleaf") != 0) {
            tree(conn, rs.getInt("id"), 1);
        }

    }

    rs.close();
    stmt.close();
    conn.close();
%>

<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gbk">
<title>Insert title here</title>
</head>
<body>

<table border ="1">
<%= str %>
</table>

</body>

</html>




文件二:
ShowArticleDetail.jsp
Java code

<%@ page language="java" contentType="text/html; charset=GBK"
    pageEncoding="GBK"%>
<%@ page import="java.sql.*"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">

<%
    String strId = request.getParameter("id");
    int id = Integer.parseInt(strId);