Setting RenderingHints from a String value-CodePudding

I'm trying to populate some RenderingHints from a value that will be set using a String (e.g. from a value in the application.properties file), but cannot get it to pass through the value when setting the field dynamically.

Is there any easy way I can achieve this? I guess I'm either missing a Cast statement, or just not understanding how reflection works. Thanks.

import java.awt.RenderingHints;
import java.lang.reflect.Field;

...

// create the string we want to populate the hint from
String myHint = "VALUE_ANTIALIAS_ON";


// create the new hints that we want to populate
RenderingHints renderingHints = new RenderingHints(null);


// setting the value directly (like this) works:
renderingHints.put(RenderingHints.KEY_ANTIALIASING, java.awt.RenderingHints.VALUE_ANTIALIAS_ON);


// but using reflection to retrieve the field:
Field hintField = RenderingHints.class.getField(myHint);


// doesn't work...
renderingHints.put(RenderingHints.KEY_ANTIALIASING, hintField);


// and gives the error:
// public static final java.lang.Object java.awt.RenderingHints.VALUE_ANTIALIAS_ON incompatible with Global antialiasing enable key

CodePudding user response：

It doesn’t work because an instance of java.lang.reflect.Field isn’t an instance of java.awt.RenderingHints. You need to get the value of the field:

final Object hint = hintField.get(null);
renderingHints.put(RenderingHints.KEY_ANTIALIASING, hint);