[BBS] Delete.jsp 05 递归删除

删除 本帖 和 它的所有孩子帖。 然后判断 本帖 的父亲帖子是否还有孩子。没有则设置为叶子帖子

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

<%!private void del(Connection conn, int id) {
        Statement stmt = null;
        ResultSet rs = null;

        try {
            stmt = conn.createStatement();
            String sql = "select * from article where pid = " + id; // 它的孩子都选出来
            rs = stmt.executeQuery(sql);
            while (rs.next()) {
                del(conn, rs.getInt("id"));
            }
            stmt.executeUpdate("delete from article where id = " + id); // 删除本帖子
        } 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();
            }
        }
    }%>

<%
    String admin = (String) session.getAttribute("admin");
    if (admin == null || !admin.equals("true")) {
        out.println("小贼! 别想通过我这关!");
        return;
    }
%>


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

    Class.forName("com.mysql.jdbc.Driver");
    String url = "jdbc:mysql://localhost/bbs?user=root&password=root";
    Connection conn = DriverManager.getConnection(url);

    conn.setAutoCommit(false);

    del(conn, id);

    Statement stmt = conn.createStatement();
    ResultSet rs = stmt.executeQuery("select count(*) from article where pid = "+ pid);
    rs.next();
    int count = rs.getInt(1);
    rs.close();
    stmt.close();

    if (count <= 0) {
        Statement stmtUpdate = conn.createStatement();
        stmtUpdate
                .executeUpdate("update article set isleaf = 0 where id = "
                        + pid);
        stmtUpdate.close();
    }

    conn.commit();
    conn.setAutoCommit(true);
    conn.close();
    response.sendRedirect("ShowArticleTree.jsp");
%>