UUID Java Type to SQL CHAR(40) - Unable to store into Array-CodePudding

I am creating a dynamic web application, I have to use Java, HTML and MySQL. I am having issues using the type UUID.

The SQL table is as follows:

CREATE TABLE `logs` (
  `uuid` char(40) COLLATE utf8_unicode_ci NOT NULL,
  `title` char(128) COLLATE utf8_unicode_ci DEFAULT NULL,
  `content` text COLLATE utf8_unicode_ci,
  `createTimestamp` date DEFAULT NULL,
  PRIMARY KEY (`uuid`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

I have a standard Log class with getters/setters for each variable.

I have an applicationDAO class that inserts logs into the database - which works fine, but I must convert the UUID to a string in order to get all fields into the database.

public int insertLog(TextLog log) throws SQLException {
        
        int rows = 0;
          try { 
                
                connection = DBConnection.getConnectionToDatabase();
                PreparedStatement ps = connection.prepareStatement(INSERT_LOG_SQL);
                
                
                ps.setObject(1, log.getUUID().toString());
                ps.setString(2, log.getTitle());
                ps.setString(3, log.getContent());
                ps.setObject(4, java.sql.Date.valueOf(java.time.LocalDate.now()));
                
                rows = ps.executeUpdate();
                
            } catch (Exception e) {
            
                e.printStackTrace();
            }
        return rows;
        
    }

Now the problem lies when I try to store the SQL table into an array.

@Override
    public List<TextLog> listLogs() {
        
        TextLog log = null;
        List<TextLog> tl = new ArrayList<>();
        
        try { 
            
            connection = DBConnection.getConnectionToDatabase();
            Statement statement = connection.createStatement();
            ResultSet rs = statement.executeQuery(SELECT_ALL_LOGS);
        
            
            while (rs.next()) { 
                log = new TextLog();
                log.setUUID(rs.getObject("uuid", java.util.UUID.class));
                log.setTitle(rs.getString("title"));
                log.setContent(rs.getString("content"));
                log.setDate(rs.getDate("createTimestamp"));

                
            }
        
        } catch (Exception e) {
        
            e.printStackTrace();
        }
    
        
        return tl;
    }

Because the field in SQL is char(40) it is not reading it as a UUID and I am getting the following error: java.sql.SQLException: Conversion not supported for type java.util.UUID

Keep in mind I have to keep the fields as is and cannot adjust.

Any thoughts on how I can get around this error?

Thanks in advance,

CodePudding user response：

Get String and then convert it to UUID:

log.setUUID(java.util.UUID.fromString(rs.getString("uuid")));