关于ListView实时数据更新有关问题

关于ListView实时数据更新问题
我最近在做外汇项目，用的是ListView视图来显示外汇数据，我的数据是从服务器中通过socket得到数据，但是我没有思路在ListView中实时更新外汇数据，服务器发送数据过来，通过过滤自己想要的货币对数据实时更新数据，有的货币对数据是不会变化的，只是哪几对有变化就更新。望大侠提出一些详细的解决思路。我下面的代码可以从服务器中得到显示出来，现在是在 ListView实时更新数据不能得到解决。
代码如下：

package com.jhconn.KVB_android.main;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;

import android.app.Activity;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.AdapterView.OnItemSelectedListener;
import android.widget.ListView;
import android.widget.SimpleAdapter;

import com.jhconn.KVB_android.util.CCDB_Helper;

public class ShowCurrencyPair extends Activity {

  private final static String[] currencyPair = new String[] { "USDCHF",
  "GBPUSD", "USDJPY", "EURUSD", "USDCAD", "EURGBP", "EURJPY",
  "GBPJPY", "GBPCHF", "NZDUSD", "NZDJPY", "NZDAUD", "AUDUSD",
  "AUDJPY", "AUDNZD", "EURAUD", "NZDCHF", "AUDCHF", "USDCNY" };

  private final String DEBUG_TAG = "showcurrencyPair";
  private String msg = null;
  private PrintWriter out = null;
  private BufferedReader br = null;
  private String[] s = new String[100];

  private int[] to = null;
  private String[] from = null;

  private Socket socket = null;
  private int j = 0;
  private Boolean iscurrencypair = false;
  private static final int SERVERPORT = 15000;
  private static final String SERVERIP = "192.168.9.10";
  private ListView lv = null;
  private List<HashMap<String, String>> fillMaps = null;

  private Cursor cursor = null;
  private static final String TABLE_RATE = "rates";
  private DataBaseLayer dataBaseLayer;

  @Override
  public void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.currencypair);
  setTheme(R.style.Transparent);
  lv = (ListView) findViewById(R.id.listview);

  from = new String[] { "rowid", "forex", "bid", "ask" };
  to = new int[] { R.id.item1, R.id.item2, R.id.item3, R.id.item4 };
  fillMaps = new ArrayList<HashMap<String, String>>();

  Handler handler = new Handler();
  handler.post(new Runnable() {
  @Override
  public void run() {
  String message = "request" + "\r\n";
  try {
  // 创建Socket
  socket = new Socket(SERVERIP, SERVERPORT);
  // 向服务器发送消息
  out = new PrintWriter(new BufferedWriter(