[Java] bbs 中帖子的树状展现 JDBC (ArticleTree.java)

import java.sql.*;

public class ArticleTree {
    public static void main(String[] args) {
        new ArticleTree().show();
    }

    public void show() {
        Connection conn = null;
        Statement stmt = null;
        ResultSet rs = null;
        try {
            Class.forName("com.mysql.jdbc.Driver");

            conn = DriverManager
                    .getConnection("jdbc:mysql://localhost/bbs?user=root&password=root");
            stmt = conn.createStatement();
            rs = stmt.executeQuery("select * from article where pid = 0");
            while (rs.next()) {
                System.out.println(rs.getString("cont"));
                tree(conn, rs.getInt("id"), 1);
            }
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if (rs != null) {
                    rs.close();
                    rs = null;
                }
                if (stmt != null) {
                    stmt.close();
                    stmt = null;
                }
                if (conn != null) {
                    conn.close();
                    conn = null;
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }

    private void tree(Connection conn, int id, int level) {
        Statement stmt = null;
        ResultSet rs = null;

        StringBuffer strPre = new StringBuffer("");
        for (int i = 0; i < level; i++) {
            strPre.append("★★★★");
        }

        try {
            stmt = conn.createStatement();
            String sql = "select * from article where pid = " + id;
            rs = stmt.executeQuery(sql);
            while (rs.next()) {
                System.out.println(strPre + rs.getString("cont"));
                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();
            }
        }
    }
}

posted @ 2013-12-19 19:18  小尼人00  阅读(215)  评论(0编辑  收藏  举报