jdbc获取数据库表结构

 public void getTables(Connection con, String catalog, String schemaPattern, String tableNamePattern) throws SQLException {
 	// 获取数据库元数据
    DatabaseMetaData metaData = con.getMetaData();
    // 查询表元数据,pattern可使用通配符查询(%,?)
    ResultSet tableRet = metaData.getTables(
            catalog,
            schemaPattern,
            tableNamePattern,
            new String[]{"TABLE","VIEW"}
    );
    // 遍历表
    while (tableRet.next()) {
        String tableName = tableRet.getString("TABLE_NAME");
        System.out.println("======" + tableName + "======");
        // 查找表字段元数据
        ResultSet colRet = metaData.getColumns(
                catalog,
                schemaPattern,
                tableName,
                "%"
        );
        // 遍历表字段
        while (colRet.next()) {
        	// 字段名
            String columnName = colRet.getString("COLUMN_NAME");
            // 字段类型
            String typeName = colRet.getString("TYPE_NAME");
            // 字段大小
            Integer columnSize = colRet.getInt("COLUMN_SIZE");
            // 数字类型精度值
            Integer decimalDigits = colRet.getInt("DECIMAL_DIGITS");
            // 可为空值
            Boolean nullable = colRet.getBoolean("NULLABLE");
            System.out.println(
                    columnName
                            + ":"
                            + typeName
                            + "(" + columnSize + "," + decimalDigits + ")"
                            + (nullable ? " nullable" : "")
            );
        }
    }
}