/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	// identifies empty tag i.e <tag1></tag> or <tag/>
    // it also supports the possibilities of white spaces around or within the tag. however tags with whitespace as value will not match.
    private static final String EMPTY_VALUED_TAG_REGEX = "\\s*<\\s*(\\w+)\\s*></\\s*\\1\\s*>|\\s*<\\s*\\w+\\s*/\\s*>";
 
	public static void main (String[] args) throws java.lang.Exception
	{
		String inputXml = "<a>\n<b>value </ b>\n< c ></ c >\n</a>\n< d />\n<e>\n</e>\n<f/>\n<g>value2</g>";
		System.out.println("output: " + inputXml.replaceAll(EMPTY_VALUED_TAG_REGEX, ""));
	}
}

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