HTTP伺服器與android客戶端的json互動
阿新 • • 發佈：2019-01-01
廢話就不多說了，直接上程式碼：
伺服器端：
①MySQL中建立一個數據庫hello，建一張表tab_user，新增欄位id，username,password。然後隨便新增幾條記錄。
②新建Java Web工程HelloServer。
③在WEB-INF目錄下的lib中引入mysql-connector-java-5.0.8-bin.jar與org.json.jar。
④新建Servlet類LoginServlet。
LoginServlet.java:
package cn.domain.hello.servlet; import java.io.BufferedReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.json.JSONArray; import org.json.JSONObject; import cn.domain.hello.bean.UserBean; import cn.domain.hello.dao.UserDao; public class LoginServlet extends HttpServlet { /** * */ private static final long serialVersionUID = 1L; /** * The doGet method of the servlet. <br> * * This method is called when a form has its tag value method equals to get. * * @param request * the request send by the client to the server * @param response * the response send by the server to the client * @throws ServletException * if an error occurred * @throws IOException * if an error occurred */ public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } /** * The doPost method of the servlet. <br> * * This method is called when a form has its tag value method equals to * post. * * @param request * the request send by the client to the server * @param response * the response send by the server to the client * @throws ServletException * if an error occurred * @throws IOException * if an error occurred */ public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("text/json;charset=UTF-8"); String reqMessage, respMessage; JSONArray reqObject = null; JSONArray respObject = null; try { BufferedReader br = new BufferedReader(new InputStreamReader( request.getInputStream(), "UTF-8")); StringBuffer sb = new StringBuffer(""); String temp; while ((temp = br.readLine()) != null) { sb.append(temp); } br.close(); reqMessage = sb.toString(); System.out.println("請求報文:" + reqMessage); reqObject = new JSONArray(reqMessage); UserDao userDao = new UserDao(); UserBean ub = userDao.getUserByName(reqObject.getJSONObject(0) .getString("username")); if (ub.getPassword() != null && ub.getPassword().equals( reqObject.getJSONObject(0).getString("password"))) { respObject = new JSONArray().put(new JSONObject().put("userId", ub.getId())); } } catch (Exception e) { e.printStackTrace(); } finally { respMessage = respObject == null ? "" : respObject.toString(); System.out.println("返回報文:" + respMessage); PrintWriter pw = response.getWriter(); pw.write(respMessage); pw.flush(); pw.close(); } } }
簡單抽象出了資料訪問層，並實現資料庫的操作，目錄結構如下，由於檔案多，詳細請下載下面的原始碼檢視：
好了，到這裡伺服器端就已經建立完成了。客戶端訪問這個servlet的URL為：http://10.0.2.2:8080/HelloServer/servlet/LoginServlet。
記住，在android中localhost指的是模擬器本身，而這裡的10.0.2.2指你的計算機伺服器本地測試IP，可改成內網或外網IP。
Android客戶端端：
①新建一個android application：Hello。
②引入org.json.jar。
③在activity_main.xml佈局檔案中加入兩個EditText，來輸入使用者名稱和密碼，新增按鈕來提交json資料。
④先封裝一下訪問網路的HTTP操作：
WebUtil.java:
⑤在MainActivity中實現登入操作：package cn.domain.hello.util; import org.apache.http.HttpResponse; import org.apache.http.client.HttpClient; import org.apache.http.client.methods.HttpPost; import org.apache.http.entity.StringEntity; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.params.BasicHttpParams; import org.apache.http.params.HttpParams; import org.apache.http.util.EntityUtils; import org.json.JSONArray; import cn.domain.hello.config.Config; public class WebUtil { public static JSONArray getJSONArrayByWeb(String methodName, JSONArray params) { String returnValue = ""; JSONArray result = null; HttpParams httpParams = new BasicHttpParams(); httpParams.setParameter("charset", "UTF-8"); HttpClient hc = new DefaultHttpClient(httpParams); HttpPost hp = new HttpPost(Config.SERVER_IP + "/HelloServer/servlet/" + methodName); try { hp.setEntity(new StringEntity(params.toString(), "UTF-8")); HttpResponse hr = hc.execute(hp); if (hr.getStatusLine().getStatusCode() == 200) { returnValue = EntityUtils.toString(hr.getEntity(), "UTF-8"); result = new JSONArray(returnValue); } } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } if (hc != null) { hc.getConnectionManager().shutdown(); } return result; } }
package cn.domain.hello.activity;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import cn.domain.hello.R;
import cn.domain.hello.config.Config;
import cn.domain.hello.util.WebUtil;
import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.ViewStub;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity {
private EditText etUsername;
private EditText etPassword;
private Button btnLogin;
private ViewGroup vsProgress;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
this.etUsername = (EditText) this.findViewById(R.id.etUsername);
this.etPassword = (EditText) this.findViewById(R.id.etPassword);
this.btnLogin = (Button) this.findViewById(R.id.btnLogin);
this.btnLogin.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String username = MainActivity.this.etUsername.getText()
.toString().trim();
String password = MainActivity.this.etPassword.getText()
.toString().trim();
if ("".equals(username)) {
Toast.makeText(MainActivity.this, "請填寫使用者名稱",
Toast.LENGTH_SHORT).show();
return;
}
if ("".equals(password)) {
Toast.makeText(MainActivity.this, "請填寫密碼",
Toast.LENGTH_SHORT).show();
return;
}
//如果已經填寫了使用者名稱和密碼，執行登入操作
executeLogin(username, password);
}
});
}
private void executeLogin(String username, String password) {
new LoginTask().execute(username, password);
}
private void onLoginComplete(Integer userId) {
if (userId == null || userId == 0) {//如果沒有獲取到使用者ID，說明登入失敗
Toast.makeText(MainActivity.this, "使用者名稱或密碼錯誤", Toast.LENGTH_SHORT)
.show();
if (vsProgress != null) {
vsProgress.setVisibility(View.INVISIBLE);
}
return;
}
if (vsProgress != null) {
vsProgress.setVisibility(View.INVISIBLE);
}
//如果成功獲取到返回的使用者ID，說明登入成功，跳轉到HelloActivity
Toast.makeText(MainActivity.this, "登陸成功", Toast.LENGTH_SHORT).show();
HelloActivity.actionStart(MainActivity.this, userId, etUsername
.getText().toString());
}
private class LoginTask extends AsyncTask<String, Void, Integer> {
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
//進行登入驗證時，顯示登入進度條
if (vsProgress == null) {
ViewStub vs = (ViewStub) findViewById(R.id.vsProgress);
vsProgress = (ViewGroup) vs.inflate();
} else {
vsProgress.setVisibility(View.VISIBLE);
}
}
@Override
protected Integer doInBackground(String... params) {
// TODO Auto-generated method stub
Integer result = null;
JSONArray reqValue;
try {
//將使用者名稱和密碼封裝到JSONArray中，進行HTTP通訊
reqValue = new JSONArray().put(new JSONObject().put("username",
params[0]).put("password", params[1]));
JSONArray rec = WebUtil.getJSONArrayByWeb(Config.METHOD_LOGIN,
reqValue);
if (rec != null) {//如果成功獲取使用者ID
result = rec.getJSONObject(0).getInt("userId");
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return result;
}
@Override
protected void onPostExecute(Integer result) {
// TODO Auto-generated method stub
super.onPostExecute(result);
//回撥
onLoginComplete(result);
}
}
}
<uses-permission android:name="android.permission.INTERNET" />好了，自己寫寫體驗一下吧。程式碼不太符合架構規範，旨在展示Android與Web伺服器的Json資料互動過程。寫的不好還望各位大神指教。
原始碼免費下載：
原始碼免費下載