Android网络请求通经常使用的是HttpURLConnection类和HttpClient类。HttpURLConnection类是由java提供的网络訪问请求类。而HttpClient类是由apache提供的。它相当于是一个增强版本号的HttpURLConnection类，换句话来说，HttpURLConnection能够做的事情HttpClient所有能够做。
因为网络请求在Android中是比較耗时的，所以不能放在主线程中，要不然会出现ANR的问题，因此网络请求通常放在线程中进行，这样就不会堵塞UI线程。能够更有利于用户的交互。下面实例涉及到对JSON数据的解析，假设不清楚的能够到点击打开链接
以下是HttpClient get请求的方式
获取网络数据的线程类
public class GetData extends Thread {
Handler handler;
String url;
public GetData(Handler handler, String url) {
this.handler = handler;
this.url = url;
}
@Override
public void run() {
// TODO Auto-generated method stub
super.run();
HttpGet httpRequest = new HttpGet(url);// 建立http get联机
HttpResponse httpResponse;
String result = null;
try {
httpResponse = new DefaultHttpClient().execute(httpRequest);
if (httpResponse.getStatusLine().getStatusCode() == 200)
result = EntityUtils.toString(httpResponse.getEntity(), "GBK"); //获取对应的字符串
try {
JSONTokener jsonParser = new JSONTokener(result);
JSONObject data = (JSONObject) jsonParser.nextValue();
JSONArray dataArray = data.getJSONArray("data");
/*for(int t=0; t<dataArray.length(); ++t){
JSONObject obj = (JSONObject) dataArray.get(t);
String s1 = (String) obj.get("data");
String s2 = (String) obj.get("content");
String s3 = obj.getString("img");
Log.e("huang", s1+" "+s2+" "+s3);
}*/
JSONObject obj = (JSONObject) dataArray.get(0);
String s1 = (String) obj.get("data");
String s2 = (String) obj.get("content");
String s3 = obj.getString("img");
//获取图片
HttpGet get = new HttpGet(s3);
HttpResponse res = new DefaultHttpClient().execute(get);
InputStream in = res.getEntity().getContent();
Bitmap img = BitmapFactory.decodeStream(in);
Message msg = new Message();
Bundle bundle = new Bundle();
bundle.putString("s1", s1);
bundle.putString("s2", s2);
msg.obj = img;
msg.setData(bundle);
handler.sendMessage(msg);
} catch (JSONException ex) {
// 异常处理代码
}
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}// 发出http请求
}
}
UI线程
public class Main extends Activity {
Handler handler;
TextView text, text1;
ImageView img;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
text = (TextView) findViewById(R.id.text);
text1 = (TextView) findViewById(R.id.text1);
img = (ImageView) findViewById(R.id.img);
handler = new Handler(){
@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
super.handleMessage(msg);
Bundle b = msg.getData();
Log.e("huang", b.getString("s1")+" "+b.getString("s2"));
text.setText(b.getString("s1"));
text1.setText(b.getString("s2"));
img.setImageBitmap((Bitmap) msg.obj);
}
};
new GetData(handler, "http://7xiwtn.com1.z0.glb.clouddn.com/data.jason.txt").start();
}
}
执行结果：
以下是HttpClient post请求的方式
事实上post请求跟get请求几乎相同，仅仅只是在一些地方不同，一般像上传数据、提交数据一般都是用post请求，由于get请求是将參数明文加入在訪问的url上，发送的数据大小有限。不安全，而post请求发送的数据量一般能够非常大，安全。
public class PostData extends Thread {
String url;
public PostData(String url) {
this.url = url;
}
@Override
public void run() {
// TODO Auto-generated method stub
super.run();
HttpPost post = new HttpPost(url);
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("mobileNo", "13826040804"));
//post.addHeader("platform", "android");
try {
post.setEntity(new UrlEncodedFormEntity(params, HTTP.UTF_8));
HttpResponse response = new DefaultHttpClient().execute(post);
if(response.getStatusLine().getStatusCode() == 200){
String result = EntityUtils.toString(response.getEntity());
Log.e("huang", result);
/*JSONTokener token = new JSONTokener(result);
JSONObject obj = (JSONObject) token.nextValue();
JSONObject obj1 = obj.getJSONObject("result");
boolean check = obj1.getBoolean("IsSuccess");
Log.e("huang", "isSuccess:"+check);*/
}
} catch (Exception e) {
// TODO Auto-generated catch block
Log.e("huang", "error");
e.printStackTrace();
}
}
}