Obfuscate Java Logging CS3 Class SO

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.TreeMap;

import org.apache.poi.openxml4j.exceptions.InvalidFormatException;
import org.apache.poi.ss.usermodel.Row;
import org.apache.poi.ss.usermodel.Sheet;
import org.apache.poi.ss.usermodel.Workbook;
import org.apache.poi.ss.usermodel.WorkbookFactory;

public class SO
{
  static private SO m_placeholder;
  private TreeMap<String, String> m_mappings;

  protected SO()
  {
    m_placeholder = null;
    m_mappings = new TreeMap<String, String>();
  }

  static public synchronized SO g()
  {
    if (m_placeholder == null)
    {
      m_placeholder = new SO();
    }
    
    return m_placeholder;
  }
    
  public String u(String theObfuscatedString)
  {  
    String u = m_mappings.get(theObfuscatedString);
  
    if (u != null)
    {
      return u;
    }
    else
    {
      return theObfuscatedString;
    }
  }
    
  public void setSOMappingsFile(File theMappingsFile)
    throws InvalidFormatException, IOException
  {
    InputStream inp = new FileInputStream(theMappingsFile);

    Workbook wb = WorkbookFactory.create(inp);
    Sheet sheet = wb.getSheetAt(0);
    Row row = null;
    
    // System.out.println("Setting Mappings start read.");
    
    for (int r = 1; r < sheet.getLastRowNum(); r++)
    {
      // System.out.println("Setting Mappings start read. - in for loop");
      row = sheet.getRow(r);
      // System.out.println("Setting Mappings start read. - got row");
      
      if ((row != null) && (row.getCell(0) != null) && (row.getCell(0).getStringCellValue() != null))
      {
        if (row.getCell(0).getStringCellValue().compareTo("") != 0)
        {
          // System.out.println("Col1 = " + row.getCell(0).getStringCellValue() + "  Col2 = " + row.getCell(1).getStringCellValue());
          m_mappings.put
                     (
                       row.getCell(0).getStringCellValue(),
                       row.getCell(1).getStringCellValue()
                     );
        }
      }
    }
    
    // System.out.println("Setting Mappings all read.");
  }
}