2020-10-22 Android 简单后端服务器的搭建方法

it2026-03-11 0

Android 简单后端服务器的搭建方法

一、后端服务器搭建，需要用到 jsp+java+tomcat。

1、安装myeclipse，不细说，自己下载安装，里面包含服务器apache-tomcat。

2、testServlet.java代码

package com.liuxiang; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; public class testServlet extends HttpServlet { private static final long serialVersionUID = 1L; public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { System.out.println("server " + "doget\n"); process(request, response); //doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //process(request, response); response.setContentType("text/html;charset=utf-8"); response.setCharacterEncoding("UTF-8"); String name=request.getParameter("user"); String pwd=request.getParameter("password"); String message = ":Welcome to android!"; System.out.println("server " + "dopost\n"); if (name.equals("admin")&&pwd.equals("android")) response.getWriter().write(name+message); else response.getWriter().write("Input Error!"); } private void process(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { String username = request.getParameter("user"); String password = request.getParameter("password"); response.setContentType("text/html"); PrintWriter out = response.getWriter(); out.println("<html><head><title>Welcome!</title></head>"); out.println("<body> Welcome my dear friend!<br>"); out.println("Your name is: " + username + "<br>"); out.println("And your age is: " + password + "</body></html>"); out.flush(); out.close(); } }

二、android app 端

1、MainActivity.java

package com.example.httpandroidappdemo; import androidx.appcompat.app.AppCompatActivity; import androidx.core.app.ActivityCompat; import java.io.ByteArrayOutputStream; import java.io.InputStream; import java.net.HttpURLConnection; import java.net.URI; import java.net.URL; import java.net.URLEncoder; import java.util.ArrayList; import java.util.List; import org.apache.http.HttpEntity; import org.apache.http.HttpResponse; import org.apache.http.NameValuePair; import org.apache.http.client.HttpClient; import org.apache.http.client.ResponseHandler; import org.apache.http.client.entity.UrlEncodedFormEntity; import org.apache.http.client.methods.HttpGet; import org.apache.http.client.methods.HttpPost; import org.apache.http.impl.client.DefaultHttpClient; import org.apache.http.message.BasicNameValuePair; import org.apache.http.util.EntityUtils; import android.Manifest; import android.app.Activity; import android.app.AlertDialog; import android.os.Bundle; import android.os.StrictMode; import android.util.Log; import android.view.View; import android.view.View.OnClickListener; import android.webkit.WebView; import android.widget.Button; import android.widget.EditText; public class MainActivity extends AppCompatActivity { EditText e1, e2; Button b_get, b_post; //申请读写权限 String permissions[] = {Manifest.permission.INTERNET}; private WebView webView; private String TAG="http android app server demo:"; /** * 根据输入流返回一个字符串 * @param is * @throwsException */ //接受数据的函数 private static String getStringFromInputStream(InputStream is) throws Exception{ ByteArrayOutputStream baos=new ByteArrayOutputStream(); byte[] buff=new byte[1024]; int len=-1; while((len=is.read(buff))!=-1){ baos.write(buff, 0, len); } is.close(); String mes=baos.toString(); baos.close(); return mes; } public void LoginByDopost(String username,String password) { String path = "http://192.168.2.84:8080/aboutAndroid/servlet/testServlet"; System.out.println("demon logindogo"+"username="+username+" password="+password); try { URL url = new URL(path); //打开一个url连接 HttpURLConnection conn = (HttpURLConnection) url.openConnection(); //设置conn 的参数 conn.setRequestMethod("POST"); conn.setConnectTimeout(5000); //获取服务器返回的状态码 //post和get方式登录的区别 (2)**************要设置头信息 Content-Type Content-Length String data = "user=" + URLEncoder.encode(username, "utf-8") + "&password=" + URLEncoder.encode(password, "utf-8") + ""; conn.setRequestProperty("Content-Type", "application/x-www-form-urlencoded"); conn.setRequestProperty("Content-Length", data.getBytes().length + ""); //post和get方式登录的区别 (3)************** 以流的形式把数据写给服务器 conn.setDoOutput(true); //设置一个标记允许输出 conn.getOutputStream().write(data.getBytes()); int code = conn.getResponseCode(); System.out.println(TAG+"code="+code); if(code==200){ //接受数据 InputStream is=conn.getInputStream(); String state=getStringFromInputStream(is); System.out.println(TAG+"state="+state); } }catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } public String LoginByGet(String username,String password){ HttpURLConnection conn=null; //一下为自己的服务器ip，10.0.2.2:8081是本机的ip，android中本机ip不是localhost String myurl = "http://192.168.2.84:8080/aboutAndroid/servlet/testServlet?"; Log.v(TAG, "LoginByGet: "); try { //拼接字符串向服务器传值 String data="user="+username+"&password="+password; URL url=new URL(myurl+data); conn=(HttpURLConnection) url.openConnection(); conn.setRequestMethod("GET"); conn.setConnectTimeout(10000); conn.setReadTimeout(5000); conn.connect(); int code=conn.getResponseCode(); System.out.println(TAG+"code="+code); if(code==200){ //接受数据 InputStream is=conn.getInputStream(); String state=getStringFromInputStream(is); System.out.println(TAG+"state="+state); } } catch (Exception e) { e.printStackTrace(); System.out.println(TAG+e); }finally{ if(conn!=null){ conn.disconnect(); } } return null; } public void LoginHttpGet() { String url = "http://192.168.2.84:8080/aboutAndroid/servlet/testServlet"; Log.v(TAG, "LoginHttpGet: "); url = url + "?user=" + e1.getText().toString() + "&password=" + e2.getText().toString(); HttpClient client = new DefaultHttpClient(); try { HttpGet httpGet = new HttpGet(new URI(url)); HttpResponse httpResponse = client.execute(httpGet); HttpEntity httpEntity = httpResponse.getEntity(); String out = EntityUtils.toString(httpEntity); new AlertDialog.Builder(MainActivity.this).setMessage(out).create().show(); Log.v(TAG, "receive data: " + out); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } public void LoginHttpDopost() { String url = "http://192.168.2.84:8080/aboutAndroid/servlet/testServlet"; Log.v(TAG, "LoginHttpDopost: "); String name = e1.getText().toString(); String pwd = e2.getText().toString(); NameValuePair nameValuePair1 = new BasicNameValuePair("user", name); NameValuePair nameValuePair2 = new BasicNameValuePair("password", pwd); List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(); nameValuePairs.add(nameValuePair1); nameValuePairs.add(nameValuePair2); try { HttpEntity requestHttpEntity = new UrlEncodedFormEntity(nameValuePairs); HttpPost httpPost = new HttpPost(url); httpPost.setEntity(requestHttpEntity); HttpClient httpClient = new DefaultHttpClient(); HttpResponse httpResponse = httpClient.execute(httpPost); HttpEntity httpEntity = httpResponse.getEntity(); String out = EntityUtils.toString(httpEntity); new AlertDialog.Builder(MainActivity.this).setMessage(out).create().show(); Log.v(TAG, "LoginHttpDopost: "+ out); } catch (Exception e) { // TODO Auto-generated catch block e.printStackTrace(); } } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); e1 = (EditText) findViewById(R.id.editText1); e2 = (EditText) findViewById(R.id.editText2); b_get = (Button) findViewById(R.id.buttonget); //ActivityCompat.requestPermissions(MainActivity.this,new String[]{Manifest.permission.INTERNET},1); StrictMode.ThreadPolicy policy=new StrictMode.ThreadPolicy.Builder().permitAll().build(); StrictMode.setThreadPolicy(policy); webView = (WebView) findViewById(R.id.wv); //如果只写下面这一句，会提示无法访问 //加载网页需要连接互联网的权限，需要在AndroidManifest中进行声明 //这样的好处：可以让用户很清楚的看到app所需要的权限 //用户并不清楚和重视权限问题，造成了病毒问题的泛滥。其实是可以避免的！ webView.loadUrl("http://192.168.2.84:8080/aboutAndroid/"); b_get.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { LoginByGet("admin","android"); LoginHttpGet(); } }); b_post = (Button) findViewById(R.id.buttonpost); b_post.setOnClickListener(new OnClickListener() { @Override public void onClick(View arg0) { LoginByDopost("admin","android"); LoginHttpDopost(); } }); } }

2、布局文件 activity_main.xml

<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" android:orientation="vertical" > <TextView android:layout_width="fill_parent" android:layout_height="wrap_content" android:text="输入进入服务器的用户名和密码：" /> <EditText android:id="@+id/editText1" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="admin"/> <EditText android:id="@+id/editText2" android:layout_width="match_parent" android:layout_height="wrap_content" android:text="android"/> <Button android:id="@+id/buttonget" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Get进入" /> <Button android:id="@+id/buttonpost" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Post进入" /> <WebView android:layout_width="match_parent" android:layout_height="match_parent" android:id="@+id/wv"></WebView> </LinearLayout>

三、测试，在真机上测试ok，这里为了方便演示，在模拟器上测试。

四、源码下载路径：https://download.csdn.net/download/qq_37858386/13012979

最新回复(0)