Android連接服務器Servlet

登陸頁面輸入用戶名和密碼，登陸成功後跳轉到主頁面，失敗時顯示錯誤信息。傳遞參數時用BasicNameValuePair的List以httpPost.setEntity的方式來做，不能用HttpParams。

userName = (EditText) this.findViewById(R.id.editTextUserName);
password = (EditText) this.findViewById(R.id.editTextPassword);
errorMsg = (TextView) this.findViewById(R.id.textViewLoginMsg);
Button loginBtn = (Button) this.findViewById(R.id.btnLogin);
loginBtn.setOnClickListener(new OnClickListener() {


	@Override
	public void onClick(View arg0) {
		String result;
		/* 發送部分 */
		try {
			HttpClient httpClient = new DefaultHttpClient();
			String address = strUrl;
			HttpPost httpPost = new HttpPost(address);
			List<BasicNameValuePair> params = new LinkedList<BasicNameValuePair>();
			params.add(new BasicNameValuePair("username", userName.getText().toString()));
			params.add(new BasicNameValuePair("password", password.getText().toString()));
			httpPost.setEntity(new UrlEncodedFormEntity(params, "utf-8")); //將參數填入POST Entity中
			
			HttpResponse httpResponse = httpClient.execute(httpPost);
			/* 接收 */
			if (httpResponse.getStatusLine().getStatusCode() == 200) {
				result = EntityUtils.toString(httpResponse.getEntity());
				/* json文本解析 */
				JSONTokener jsonParser = new JSONTokener(result);
				
				JSONObject jsonResult = (JSONObject) jsonParser.nextValue();
				String status = jsonResult.getString("loginStatus");
				String outMessage = jsonResult.getString("outMessage");
				if(status.equals("true")){


					Intent i = new Intent(LoginActivity.this, MainActivity.class);
					i.putExtra("username", outMessage);
					startActivityForResult(i, FIRST_REQUEST_CODE);
				} else {
					errorMsg.setVisibility(View.VISIBLE);
					errorMsg.setText(outMessage);
				}
			} else {
				errorMsg.setVisibility(View.VISIBLE);
				errorMsg.setText("網絡連接問題。CODE:" + httpResponse.getStatusLine().getStatusCode());
			}
		} catch (JSONException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		} catch (ClientProtocolException e) {
			e.printStackTrace();
		} catch (IOException e) {
			e.printStackTrace();
		}


	}
});