利用Volley框架实现简单的Android与servlet信息交互

莫道桑榆晚，为霞尚满天。这篇文章主要讲述利用Volley框架实现简单的Android与servlet信息交互相关的知识，希望能为你提供帮助。
写这篇文章之前，我参考了这篇帖子内容https://blog.csdn.net/Mr_Megamind/article/details/74048891
先来进行servlet服务器的搭建
这里我就实现简单的获取来自客户端的信息，并返回一些信息
直接上代码：

package serverlet; import java.io.IOException; import java.io.PrintWriter; import java.util.HashMap; import java.util.Map; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import net.sf.json.JSONObject; /** * Servlet implementation class net */ @WebServlet("/net") public class net extends HttpServlet { private static final long serialVersionUID = 1L; /** * @see HttpServlet#HttpServlet() */ public net() { super(); // TODO Auto-generated constructor stub } /** * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) */ protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub response.setCharacterEncoding("utf-8"); //设置 HttpServletResponse使用utf-8编码 response.setHeader("Content-Type", "text/html; charset=utf-8"); //通知浏览器使用utf-8解码response.getWriter().append("Served at: ").append(request.getContextPath()); request.setCharacterEncoding("utf-8"); try (PrintWriter out = response.getWriter()) {//获得请求中传来的用户名和密码 String accountNumber = request.getParameter("AccountNumber"); String password = request.getParameter("Password"); String s=accountNumber+password; System.out.println(s); Map< String, String> params = new HashMap< > (); JSONObject jsonObject = new JSONObject(); params.put("Result",s); jsonObject.put("params",params); System.out.println(jsonObject.toString()); response.resetBuffer(); //清空原有的输出流，方便客户端获取到json字符串out.write(jsonObject.toString()); //将json字符串写入输出流 } } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */ protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub doGet(request, response); }}

接下来是客户端的代码
使用Volley首先要在项目中添加Volley.jar包
接下来是使用步骤
1.创建RequestQuene对象,定义网络请求队列;
2.创建**Request对象，**代表String、JSON、Image用于定义网络请求的接收，这里我使用的是StringRequest；
3.把**Request请求对象添加到RequestQuene对象中，开始执行网络请求；
【利用Volley框架实现简单的Android与servlet信息交互】4.在androidManifest中注册,添加网络权限；
这里先附上添加网络权限的语句：

< uses-permission android:name="android.permission.INTERNET" />

然后是app内进行网络请求的函数体的代码

publicvoid LoginRequest(final String accountNumber, final String password) { //请求地址 String url = "http://域名:端口号/MyFirstWebApp/LoginServlet"; String tag = "Login"; //取得请求队列 RequestQueue requestQueue = Volley.newRequestQueue(getApplicationContext()); //防止重复请求，先取消tag标识的请求队列 requestQueue.cancelAll(tag); //创建StringRequest，定义字符串请求的请求方式为POST(省略第一个参数会默认为GET方式) final StringRequest request = new StringRequest(Request.Method.POST, url, new Response.Listener< String> () { @Overridepublic void onResponse(String response) {try {//将传回的字符串转化为JSONObject JSONObject jsonObject = (JSONObject) newJSONObject(response).get("params"); String result = jsonObject.getString("Result"); //result的值就是servlet传回的result的值，对应的就是servlet中s的值 text.setText(result); //这部分内容是对返回信息的使用，text是一个Textview} catch (JSONException e) { //请求异常操作 Toast.makeText(MainActivity.this.getApplicationContext(),"无网络",Toast.LENGTH_SHORT).show(); }} }, new Response.ErrorListener() { @Override public void onErrorResponse(VolleyError error) { //响应错误操作Toast.makeText(MainActivity.this.getApplicationContext(),"响应错误",Toast.LENGTH_SHORT).show(); } }) { @Override protected Map< String, String> getParams() throws AuthFailureError { Map< String, String> params = new HashMap< > (); params.put("AccountNumber", accountNumber); //注⑥ params.put("Password", password); return params; } }; //设置Tag标签 request.setTag(tag); //将请求添加到队列中 requestQueue.add(request); }@Override protected Response< String> parseNetworkResponse(NetworkResponse response) { String str = null; try { str = new String(response.data, "utf-8"); } catch (UnsupportedEncodingException e) { e.printStackTrace(); }return Response.success(str, HttpHeaderParser.parseCacheHeaders(response)); } }