Wide table word java

I have:

XWPFTable header = document.createTable(1 , 2); 
header.getRow(0).getCell(0).setColor("dbdbdb")
header.getRow(0).getCell(0).setText("titulo")
header.getRow(0).getCell(1).setText("valor1")

When the word is generated, the width of the table adapts to the text, but I would like to give a 30% to the title and a 70% to the value, is it possible?