Java php发现了类似的单词

好的，我的应用程序会从我网站内的数据库中找到你在文本框中键入的单词。。它会找到"单词"，如果有超过1个"单词"它会遍历每个单词并随机选择一个"回复"

我该怎么做，这样如果它找不到"嘿"这个词，它就会寻找类似的词，比如"他"等等？

这是我的PHP：

    <?php
// Connect to database
mysql_connect("server", "db username", "db password");
mysql_select_db("db405677000");
// If something is received
if($_POST)
{
    if($_POST['action'] == "ask")
    {
        // Filter it to prevent SQL injections
        $text = mysql_real_escape_string($_POST['stringdata']);
        // Search it on the database
        $q = mysql_query("SELECT `reply` FROM `poka` WHERE `word` = '$text' ORDER BY RAND()");
        // Show result
        if($r = mysql_fetch_assoc($q))
            echo $r['reply'];
        else
            echo "Cannot find a reply";
    }
    elseif($_POST['action'] == "teach")
    {
        // Filter it to prevent SQL injections
        $word = mysql_real_escape_string($_POST['word']);
        $answer = mysql_real_escape_string($_POST['answer']);
        // Insert it to the database
        if( mysql_query("INSERT INTO `poka` VALUES(NULL, '$word', '$answer')") )
            echo "ok";
        else
            echo "fail";
    }
}
?>

这是我的java部分，它实际上得到了响应：

public void responseGet(String textRequest)
{
    EditText textbox = (EditText)findViewById(R.id.chat);
    textbox.setText("");
    TableLayout chatbox = (TableLayout)findViewById(R.id.chatbox);
    if(canReply == false)
    {
        TableRow tr1 = new TableRow(this);
        tr1.setLayoutParams(new LayoutParams( LayoutParams.FILL_PARENT,LayoutParams.WRAP_CONTENT));
        TextView textview = new TextView(this);
        // Create a new HttpClient and Post Header
        HttpClient httpclient = new DefaultHttpClient();
        HttpPost httppost = new HttpPost("http://monaiz.net/get.php");
        String responseStr = "";
        try {
            // Add your data
            List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2);
            nameValuePairs.add(new BasicNameValuePair("stringdata", textRequest));
            nameValuePairs.add(new BasicNameValuePair("action", "ask"));
            httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
            // Execute HTTP Post Request
            HttpResponse response = httpclient.execute(httppost);
            HttpEntity entity = response.getEntity( );
            responseStr = EntityUtils.toString( entity ).replace("''", "");
        } catch (Exception e) {
            // TODO Auto-generated catch block
        }
        textview.setText(responseStr);
      //  textview.getTextColors(R.color.)
        textview.setTextColor(Color.BLACK);
        textview.setGravity(Gravity.LEFT);
         tr1.addView(textview);
      // Convert dp to px
            int padding_in_dp = 7;
            final float scale = getResources().getDisplayMetrics().density;
            int padding_in_px = (int) (padding_in_dp * scale + 0.5f);
            tr1.setPadding(padding_in_px, 0, padding_in_px, 0);
         tr1.setBackgroundResource(R.drawable.pokaspeak);
         tr1.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    Intent startNewActivityOpen = new Intent(main.this, TeachmeDialog.class);
                    startActivityForResult(startNewActivityOpen, 0);
                }
              });
            chatbox.addView(tr1, new TableLayout.LayoutParams(
                    LayoutParams.FILL_PARENT,
                   LayoutParams.WRAP_CONTENT));
           canReply = true;

           new Handler().postDelayed(new Runnable() {
               @Override
               public void run() {
                ScrollView s = (ScrollView) findViewById(R.id.SV);
                s.fullScroll(View.FOCUS_DOWN);
               }
           },100);
    }
}