第十五天 乐在其中-Android与远端之POST方式

         4月26日，晴天。“已是早春二月天,今夜忽遇倒春寒”。

   1、服务器端

          （1）工程视图

         （2）ServletForPost.java

package com.servlet.post;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;@WebServlet("/ServletForPost")public class ServletForPost extends HttpServlet {private static final long serialVersionUID = 1L;           public ServletForPost() {        super();            }protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {}protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {request.setCharacterEncoding("UTF-8");String name= request.getParameter("name");String age= request.getParameter("age");System.out.println("name from POST method: " + name );System.out.println("age from POST method: " + age );}}

               （4）运行http://192.168.23.1:8080/ServerForPOST/ServletForPost
          注意：IP:192.168.23.1:8080，是WIFI共享精灵设置的虚拟的无线网卡的IP，IP自然由虚拟的无线路由分配，使用手机连接，会自动给手机分配同一网段的IP：如：192.168.23.2。
         因为在android模拟器中访问本机中的tomcat服务器时，注意：不能写localhost，因为模拟器是一个单独的手机系统，所以要写真是的IP地址。否则无法访问到服务器。
        2、手机端代码
          （1）工程视图

                （2）MainActivity.java

package com.androidpostmethod;import android.app.Activity;import android.os.Bundle;import android.view.Menu;import android.view.View;import android.widget.EditText;import android.widget.Toast;public class MainActivity extends Activity {private EditText titleText;private EditText lengthText;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);titleText = (EditText) this.findViewById(R.id.title);lengthText = (EditText) this.findViewById(R.id.length);}public void save(View v) {String title = titleText.getText().toString();String length = lengthText.getText().toString();try {boolean result = false;result = UploadUserInformationByPostService.save(title, length);if (result) {Toast.makeText(this, R.string.success, Toast.LENGTH_SHORT).show();} else {Toast.makeText(this, R.string.fail, Toast.LENGTH_SHORT).show();}} catch (Exception e) {e.printStackTrace();Toast.makeText(this, "Exception error", Toast.LENGTH_SHORT).show();}}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}}

             （3）UploadUserInformationByPostService.java

package com.androidpostmethod;import java.io.OutputStream;import java.net.HttpURLConnection;import java.net.URL;import java.net.URLEncoder;import java.util.HashMap;import java.util.Map;public class UploadUserInformationByPostService {public static boolean save(String title, String length) throws Exception {String path = "http://192.168.23.1:8080/ServerForPOST/ServletForPost";Map<String, String> params = new HashMap<String, String>();params.put("name", title);params.put("age", length);return sendPOSTRequest(path, params, "UTF-8");}private static boolean sendPOSTRequest(String path,Map<String, String> params, String encoding) throws Exception {StringBuilder sb = new StringBuilder();if (params != null && !params.isEmpty()) {for (Map.Entry<String, String> entry : params.entrySet()) {sb.append(entry.getKey()).append("=");sb.append(URLEncoder.encode(entry.getValue(), encoding));sb.append("&");}sb.deleteCharAt(sb.length() - 1);}byte[] data = sb.toString().getBytes();HttpURLConnection conn = (HttpURLConnection) new URL(path).openConnection();conn.setConnectTimeout(5000);conn.setRequestMethod("POST");conn.setDoOutput(true);conn.setRequestProperty("Content-Type","application/x-www-form-urlencoded");conn.setRequestProperty("Content-Length", data.length + "");OutputStream outStream = conn.getOutputStream();outStream.write(data);outStream.flush();if (conn.getResponseCode() == 200)return true;return false;}}

            （4）activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:tools="http://schemas.android.com/tools"    android:layout_width="match_parent"    android:layout_height="match_parent"    android:orientation="vertical"    android:paddingBottom="@dimen/activity_vertical_margin"    android:paddingLeft="@dimen/activity_horizontal_margin"    android:paddingRight="@dimen/activity_horizontal_margin"    android:paddingTop="@dimen/activity_vertical_margin"    tools:context=".MainActivity" >    <TextView      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="@string/title"    />        <EditText     android:layout_width="fill_parent"      android:layout_height="wrap_content"      android:id="@+id/title"    />        <TextView      android:layout_width="fill_parent"     android:layout_height="wrap_content"     android:text="@string/length"    />        <EditText     android:layout_width="fill_parent"      android:layout_height="wrap_content"      android:numeric="integer"     android:id="@+id/length"    />        <Button    android:layout_width="wrap_content"     android:layout_height="wrap_content"     android:text="@string/button"    android:onClick="save"    /></LinearLayout>

         （5）strings.xml

<?xml version="1.0" encoding="utf-8"?><resources>    <string name="app_name">AndroidPostMethod</string>    <string name="hello_world">Hello world!</string>    <string name="action_settings">Settings</string>        <string name="title">name</string>    <string name="length">age</string>    <string name="button">保存</string>    <string name="success">Succeeded to save</string>    <string name="fail">Failed to save</string></resources>

          （6）AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android"    package="com.androidpostmethod"    android:versionCode="1"    android:versionName="1.0" >    <uses-sdk        android:minSdkVersion="8"        android:targetSdkVersion="8" />    <application        android:allowBackup="true"        android:icon="@drawable/ic_launcher"        android:label="@string/app_name"        android:theme="@style/AppTheme" >        <activity            android:name="com.androidpostmethod.MainActivity"            android:label="@string/app_name" >            <intent-filter>                <action android:name="android.intent.action.MAIN" />                <category android:name="android.intent.category.LAUNCHER" />            </intent-filter>        </activity>    </application> <uses-permission android:name="android.permission.INTERNET"/></manifest>

        3、安卓模拟器运行结果

                eclipse的console会打印以下结果：

       

              4、手机运行结果-手机截屏

                        

              eclipse的console会打印以下结果：