Android定时从服务器获取数据并刷新?这是很多进行Android培训的学员所不太清楚的一个知识点,在课上很多同学都会就这个问题向达内老师进行提问,下面就让我们一起来学习一下。
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.HttpStatus;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.apache.http.util.EntityUtils;
import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class Test extends Activity implements Runnable {
/** Called when the activity is first created. */
private Button btn_get = null;
private Button btn_post = null;
private TextView tv_rp = null;

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
btn_get = (Button) this.findViewById(R.id.Button01);
btn_post = (Button) this.findViewById(R.id.Button02);
tv_rp = (TextView) this.findViewById(R.id.TextView);
btn_get.setOnClickListener(new Button.OnClickListener() {

public void onClick(View v) {
// TODO Auto-generated method stub
String httpUrl = "http://192.168.0.132:8080/Android/httpreq.jsp?par=request-get";
HttpGet request = new HttpGet(httpUrl);
HttpClient httpClient = new DefaultHttpClient();
try {
HttpResponse response = httpClient.execute(request);
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
String str = EntityUtils.toString(response.getEntity());
tv_rp.setText(str);
} else {
tv_rp.setText("请求错误");
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

});
btn_post.setOnClickListener(new Button.OnClickListener() {

public void onClick(View v) {
// TODO Auto-generated method stub
String httpUrl = "http://192.168.0.132:8080/Android/httpreq.jsp";
HttpPost request = new HttpPost(httpUrl);
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("par", "request-post"));
try {
HttpEntity entity = new UrlEncodedFormEntity(params,
"UTF-8");
request.setEntity(entity);
HttpClient client = new DefaultHttpClient();
HttpResponse response = client.execute(request);
if (response.getStatusLine().getStatusCode() == HttpStatus.SC_OK) {
String str = EntityUtils.toString(response.getEntity());
tv_rp.setText(str);
} else {
tv_rp.setText("请求错误");
}
} catch (UnsupportedEncodingException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

});
new Thread(this).start();
}

public void refresh() {
String httpUrl = "http://192.168.0.132:8080/Android/httpreq.jsp";
try {
URL url = new URL(httpUrl);
HttpURLConnection urlConn = (HttpURLConnection) url
.openConnection();
urlConn.connect();
InputStream input = urlConn.getInputStream();
InputStreamReader inputreader = new InputStreamReader(input);
BufferedReader reader = new BufferedReader(inputreader);
String str = null;

StringBuffer sb = new StringBuffer();
while ((str = reader.readLine()) != null) {
sb.append(str).append("\n");
}
if (sb != null) {
tv_rp.setText(sb.toString());
} else {
tv_rp.setText("NULL");
}
reader.close();
inputreader.close();
input.close();
reader = null;
inputreader = null;
input = null;
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

public Handler handler = new Handler() {
public void handleMessage(Message msg) {
super.handleMessage(msg);
refresh();
}
};

public void run() {
// TODO Auto-generated method stub
while (true) {
try {
Thread.sleep(1000);
handler.sendMessage(handler.obtainMessage());
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}

好了,说到这里相信同学们对Android定时从服务器获取数据并刷新已经有一个自己的认识了,达内老师希望同学们在以后遇到问题时都能够积极的思考并寻求解答。

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