Try to work with the helping elements before looking at the solution…

Helping elements

• the method might be called write () or writeTrees ()

• it may be a static method located in Training

• it takes 2 arguments: (List trees, String fileName)

• to create the file, use java.io.BufferredWriter

• you can write: BufferedWriter out = new BufferedWriter(new FileWriter(fileName));

• a tab can be coded in a char variable: '\t' or in a String: “\t”

• the header line should start with #

• in this exercise, z = 0

• to write a line in the file: out.write (line); out.newLine ();

• loop on the trees in the given list, cast each element into a SpatializedTree

• prepare the line by appending parts in a String: String line = “” + t.getId () + tab + …

• close the file at the end: out.close ();

• enclose all the method content in a try {} catch () {} clause

• in case of Exception, write a message with System.out.println (…) then throw the exception back to caller

• add lines in main() after the previous exercise where you built a list of trees, and write the trees in a file called trees.txt

A possible solution