java.sql.Blob cannot be resolved to a type

[Glyndwr Bartlett]

Hi,

I have just updated my Eclipse to Version: 2024-09 (4.33.0) and now I am getting the error "java.sql.Blob cannot be resolved to a type" on the line "java.sql.Blob imageBlob = result.getBlob(1);". In fact all instances of "java.sql.Blob" are now in error. The code is:

   

public static String getMedicalPlanImageData(String id){
		
		PreparedStatement ps = null;
		String imageDataString = null;
		// Create connection/statement variables outside of try block
	    Connection c = null;
	    
	    String selectQry = ("SELECT mp_image " +
			      "FROM at_medical_plan " + 
			      "WHERE mp_id = ?;");
	    
	    try {
	    	// Get Connection and Statement from DataSource
	        c = ds.getConnection();
	        ps = c.prepareStatement(selectQry);
	        
	        try {
				// Read in the image from the database.
	        	
	        	ps.setString(1, id);
	        	
	        	// Get result set
		    	ResultSet result = ps.executeQuery();
				
				while (result.next()) {
					java.sql.Blob imageBlob = result.getBlob(1); //Error on this line
					byte[] imageData = imageBlob.getBytes(1, (int) imageBlob.length());
					
					//Convert Image byte array into Base64 String
					imageDataString = encodeImage(imageData);
					imageDataString = "data:application/pdf;base64,"+imageDataString;
				}
				
				// Clean up
	            ps.close();
	            c.close();
	            
	        } catch (SQLException se) {
	    		System.out.println("SQLException in getMedicalPlanImageData: " + se.toString());
		    } catch (Exception e) {
		        System.out.println("Errors occurred in getMedicalPlanImageData: " + e.toString());
		    }

	    } catch (SQLException e1) {
		    System.out.println("SQLException in getMedicalPlanImageData: " + e1.toString());
			e1.printStackTrace();
	            
	    } finally {
	    	try {
	        	if(ps != null) ps.close();
	        	if(c != null) c.close();
        	} 
	        catch (Exception e) {
	        	System.out.println("Exception in getMedicalPlanImageData: " + e.toString());
        	}
	    }
    	// Done		
		return imageDataString;
	}

Kind regards,
Glyn

[Glyndwr Bartlett]

I am using JavaSE-21 (jdk-22.0.1).

[Tim Holloway]

Normally when I do a web search for Javadocs what comes back applies to some long-ago Java version.

So I tracked down the Java 21 docs specifically. And Blob is alive and well. Blob is an interface, not an instantiable class, though. I don't think that matters for your sample code.

So chances are that you haven't got Eclipse set up properly. Note that the JVM version setup for a project doesn't have to be the same as the one used by Eclipse itself, though.

[Paul Clapham]

I don't have access to my copy of Eclipse right now, but "Java SE21 (jdk22.0.1)" looks weird to me. Java 21 or 22 or some weird mashup? Look at where that comes from.

[Tim Holloway]

Paul Clapham wrote:I don't have access to my copy of Eclipse right now, but "Java SE21 (jdk22.0.1)" looks weird to me. Java 21 or 22 or some weird mashup? Look at where that comes from.

I think it's JDK 22 running at compatability level 21. ?

[Glyndwr Bartlett]

Hi,

Thank you everyone for your help. As suspected by you it was an Eclipse bug. When I just started up Eclipse, ready to re-connect the JRE, there was only one error message instead of the many tens of error messages (one for each use of Blob) yesterday. Strangely this was an error in relation to the "import java.sql.Blob"; however, it was against the first line ("package server;"). This then disappeared before I could get a screen grab to prove it! I did a clean of the project and the error(s) did not reappear. So, all is good for now.

Once again, thank you for your help.

Kind regards,
Glyn