怎样实现android http-post方法实例说明

package com.hl;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;

public class SimplePOST extends Activity {
private TextView show;
private EditText txt;
private Button btn;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
show = (TextView)findViewById(R.id.show);
txt = (EditText)findViewById(R.id.txt);
btn = (Button)findViewById(R.id.btn);
btn.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
dopost(txt.getText().toString());

}
});
}

private void dopost(String val){
//封装数据
Map<String, String> parmas = new HashMap<String, String>();
parmas.put("name", val);

DefaultHttpClient client = new DefaultHttpClient();//http客户端
HttpPost httpPost = new HttpPost("http://mhycoe.com/test/post.php");

ArrayList<BasicNameValuePair> pairs = new ArrayList<BasicNameValuePair>();
if(parmas != null){
Set<String> keys = parmas.keySet();
for(Iterator<String> i = keys.iterator(); i.hasNext();) {
String key = (String)i.next();
pairs.add(new BasicNameValuePair(key, parmas.get(key)));
}
}

try {
UrlEncodedFormEntity p_entity = new UrlEncodedFormEntity(pairs, "utf-8");
/*
* 将POST数据放入HTTP请求
*/
httpPost.setEntity(p_entity);
/*
* 发出实际的HTTP POST请求
*/
HttpResponse response = client.execute(httpPost);
HttpEntity entity = response.getEntity();
InputStream content = entity.getContent();
String returnConnection = convertStreamToString(content);
show.setText(returnConnection);
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}

}

private String convertStreamToString(InputStream is) {
BufferedReader reader = new BufferedReader(new InputStreamReader(is));
StringBuilder sb = new StringBuilder();
String line = null;
try {
while ((line = reader.readLine()) != null) {
sb.append(line);
}
} catch (IOException e) {
e.printStackTrace();
} finally {
try {
is.close();
} catch (IOException e) {
e.printStackTrace();
}
}
return sb.toString();
}
}