iterate through map and write the content in a separate file

I am trying to save the data from file to a map, then iterate through map and write it to a separate file.My data looks like this:

Concept:Conferences:conferences:confID Concept:Organizations:organizations:orgID Property:conferencesName:namespace:conferences.Name Property:conferencesDate:namespace:conferences.Date

Here are the steps that I did and planning to perform:

1. I wrote a code that reads through the above file and save it in maps depending on if it
   is a concept or a property.

2. Next step would be to create a method that write the lines below into a separate file that already exists in computer. map: a d2rq:ClassMap;

   map: a d2rq:PropertyBridge;

3. The last step would be to iterate through the maps and if it is a concept map write the "key" into the "blank (line 1)" above in step 2 and vice versa for property.

I am new to programming and kind of stuck with steps 2 and 3. Can somebody help me! Please find my code for step 1 here

import java.io.*;
import java.util.*;  

public class ReadAndStoreManual {

public static void main(String[] args)  {
Map<String, List<String>> conceptMap = new HashMap<String, List<String>>();
Map<String, List<String>> PropertyMap = new HashMap<String, List<String>>();
try{
Scanner scanner = new Scanner(new FileReader("C:/"));

while (scanner.hasNextLine()){
String nextLine = scanner.nextLine();
String [] column = nextLine.split(":");
if (column[0].equals ("Concept")){
if (column.length == 4) {
PropertyMap.put(column [1], Arrays.asList(column[2], column[3]));   
    }
else {
conceptMap.put (column [1], Arrays.asList (column[2], column[3]));
    }
}

}
scanner.close();

}

 catch (Exception e) {
 e.printStackTrace();

 }
 System.out.println(conceptMap);
 System.out.println(PropertyMap);

}

}