WhatsApp-Message Listing of specific person's message in a WhatsApp group step 1: Save the contact in phone for which the person you want to extract the chat step 2: Extract the WhatsAPP group chats in a file (By exporting it to mail) step 3: run open demoregex.java file. And change the file name "chat.txt" with your file. step 4: change the Name of person at line 17 as mention in comment step 5: compile the java file as javac -source 8 demoregex.java step 6: Run the java file as java demoregex