java - Exchange crypto key through sockets -

what making chat program encrypts/decrypts messages send. far i've established basic all-to-all communication clients , have put server-to-client simple encryption aes, have given them same key. want establish key exchange algorithm allow every client have own key. have read multiple algorithms, @ first wanted establish diffie-hellman found rsa examples made more sence. have:

public static void main(string[] args) throws nosuchalgorithmexception, nosuchpaddingexception,  invalidkeyexception, illegalblocksizeexception, badpaddingexception  {  keygenerator keygenerator = keygenerator.getinstance("aes"); keygenerator.init(128); key aeskey = keygenerator.generatekey();    keypairgenerator keypairgenerator = keypairgenerator.getinstance("rsa"); keypairgenerator.initialize(1024); keypair keypair = keypairgenerator.genkeypair();  cipher cipher = cipher.getinstance("rsa/ecb/pkcs1padding");  byte[] aeskeybytes = aeskey.getencoded(); system.out.println("1. aeskeybytes= "+ bytestohex(aeskeybytes));  cipher.init(cipher.encrypt_mode, keypair.getpublic()); byte[] ciphertext = cipher.dofinal(aeskeybytes); system.out.println("2. ciphertext= "+bytestohex(ciphertext));  cipher.init(cipher.decrypt_mode, keypair.getprivate()); byte[] decryptedkeybytes = cipher.dofinal(ciphertext); system.out.println("3. decryptedkeybytes= "+bytestohex(decryptedkeybytes));   //use symmetric decrypted key secretkey newaeskey = new secretkeyspec(decryptedkeybytes, "aes"); 

basically point code ends use secretkey initialize aes cipher , go on there. question how distribute keys rsa through sockets without losing bytes or whatever clients can have unique keypairs server. there way not use keygenerator , give own keys strings, since plan on using setters user can change his/her key on whish, otherwise what's point in using keyexchange if clients end having same keys in first place? , 1 last thing purely on curiosity, possible modify rsa dh, , how different code-wise? lastly "bytestohex" method follows , provided me teacher , after tested works fine there no problems there:

public static string bytestohex(byte[] data) {      if (data==null)         return null;     else     {         int len = data.length;          string str = "";          (int i=0; i<len; i++)         {             if ((data[i]&0xff)<16){                 str = str + "0" + java.lang.integer.tohexstring(data[i]&0xff);                             }                             else{                 str = str + java.lang.integer.tohexstring(data[i]&0xff);                             }         }          return str.touppercase();     } } 

i know there might answers "look @ this" , "this example", trust me i've looked @ of them got more confused. clear don't want use files store keys or that, want client , server send each other public keys along private key create secretkey, know dh fed right i'll take can have appreciated.