hashtable to file

[kavins]

How to write from a hashtable to a file

[Michael Zalewski]

If you just want to log it (and if the keys and values are all readable, such as Strings or Integers), just write it to a PrintWriter -> File Writer:

  PrintWriter pwMyLogFile = new PrintWriter(
      new FileWriter( sLogFileName)
  );
  pwMyLogFile.println( "Hash table = " + hshMyHashMap);

It prints like this
Hash table = {Key1=Value1, Key2=Value2, ... }
If you need to read it back in a program (and if the keys and values are all Serializable or Externalizable), you might want to use a RandomAccessFile <- ByteArrayOutputStream.writeObject( hashMap) or FileOutputStream <- ObjectOutputStream

[Dave Landers]

If everything (keys and values) in the Hashtable are Strings, you can shove them all in a Properties and store() it:
Properties p = new Properties();
p.putAll( theHashTable );
p.store( outputStream, "foo" );
This will only work if the hashtable is composed of only strings.