java读取mysql表的注释及字段注释

/**
 * 读取mysql某数据库下表的注释信息
 * 
 * @author xxx
 */
public class MySQLTableComment {
    public static Connection getMySQLConnection() throws Exception {
        Class.forName("com.mysql.jdbc.Driver");
        Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/databaseName", "root", "root");
        return conn;
    }
    

    /**
     * 获取当前数据库下的所有表名称
     * @return
     * @throws Exception
     */
    public static List getAllTableName() throws Exception {
        List tables = new ArrayList();
        Connection conn = getMySQLConnection();
        Statement stmt = conn.createStatement();
        ResultSet rs = stmt.executeQuery("SHOW TABLES ");
        while (rs.next()) {
            String tableName = rs.getString(1);
            tables.add(tableName);
        }
        rs.close();
        stmt.close();
        conn.close();
        return tables;
    }
    

    /**
     * 获得某表的建表语句
     * @param tableName
     * @return
     * @throws Exception
     */
    public static Map getCommentByTableName(List tableName) throws Exception {
        Map map = new HashMap();
        Connection conn = getMySQLConnection();
        Statement stmt = conn.createStatement();
        for (int i = 0; i < tableName.size(); i++) {
            String table = (String) tableName.get(i);
            ResultSet rs = stmt.executeQuery("SHOW CREATE TABLE " + table);
            if (rs != null && rs.next()) {
                String createDDL = rs.getString(2);
                String comment = parse(createDDL);
                map.put(table, comment);
            }
            rs.close();
        }
        stmt.close();
        conn.close();
        return map;
    }
    /**
     * 获得某表中所有字段的注释
     * @param tableName
     * @return
     * @throws Exception
     */
    public static void getColumnCommentByTableName(List tableName) throws Exception {
        Map map = new HashMap();
        Connection conn = getMySQLConnection();
        Statement stmt = conn.createStatement();
        for (int i = 0; i < tableName.size(); i++) {
            String table = (String) tableName.get(i);
            ResultSet rs = stmt.executeQuery("show full columns from " + table);
            System.out.println("【"+table+"】");
//            if (rs != null && rs.next()) {
                //map.put(rs.getString("Field"), rs.getString("Comment"));
            while (rs.next()) {   
//                System.out.println("字段名称：" + rs.getString("Field") + "\t"+ "字段注释：" + rs.getString("Comment") );
                System.out.println(rs.getString("Field") + "\t:\t"+  rs.getString("Comment") );
            } 
//            }
            rs.close();
        }
        stmt.close();
        conn.close();
//        return map;
    }

    

    /**
     * 返回注释信息
     * @param all
     * @return
     */
    
    public static String parse(String all) {
        String comment = null;
        int index = all.indexOf("COMMENT='");
        if (index < 0) {
            return "";
        }
        comment = all.substring(index + 9);
        comment = comment.substring(0, comment.length() - 1);
        return comment;
    }

    public static void main(String[] args) throws Exception {
        List tables = getAllTableName();
        Map tablesComment = getCommentByTableName(tables);
        Set names = tablesComment.keySet();
        Iterator iter = names.iterator();
        while (iter.hasNext()) {
            String name = (String) iter.next();
            System.out.println("Table Name: " + name + ", Comment: " + tablesComment.get(name));
        }
        
        getColumnCommentByTableName(tables);
    }