android访问servlet

① android客户端和服务器端怎么交互

android客户端和服务器端是基于IntentService的，具体如下：

1. 后台使用简单的servlet，支持GET或POST。这个servlet最终返回给前台一个字符串flag，值是true或false，表示登录是否成功。

2. 然后在安卓的ADT上创建一个安卓项目，建立两个Activity，分别作为登录界面和登录成功界面。

3. HTTP的访问公共类，用于处理GET和POST请求。

4. IntentService服务，用于在后台以队列方式处理耗时操作。

5. 在AndroidManifest.xml中注册IntentService。注意uses-permission节点，为程序开启访问网络的权限。

6. 登陆界面处理，注意按钮监听事件中，使用Intent将要传递的值传给service。接收广播类中，同样使用Intent将要传递的值传给下一个Activity。在onCreate()中，动态注册接收广播类的实例receiver。在接收广播类中，不要使用完毕后忘记注销接收器，否则会报一个Are you missing a call to unregisterReceiver()? 的异常。

   
   

② java服务端android客户端如何通信

一、HTTP请求(APACHE的HttpClient实现)
服务器端，就是普通的servlet、Strutus2就可以
移动端
protected static String get(String url, List<NameValuePair> params) {
String resultMsg;

// 设置http请求配置
HttpParams parms = new BasicHttpParams();
parms.setParameter("charset", HTTP.UTF_8);
// 配置连接超时
HttpConnectionParams.setConnectionTimeout(parms, 10 * 1000);
// 设置请求超时
HttpConnectionParams.setSoTimeout(parms, 15 * 1000);
// 实例化HttpClient
HttpClient httpclient = new DefaultHttpClient(parms);
// 实例化HttpGet
HttpGet httpget = new HttpGet(url);
// 设置请求头
httpget.addHeader("Content-Type", "application/json");
httpget.addHeader("charset", HTTP.UTF_8);

try {
if (params.size() > 0)
url = url + "?" + URLEncodedUtils.format(params, HTTP.UTF_8);

HttpResponse resp = httpclient.execute(httpget);
int statusCode = resp.getStatusLine().getStatusCode();

if (statusCode == HttpStatus.SC_OK) {
StringBuffer result = getResponse(resp);
resultMsg = result.toString();
} else {
resultMsg = "连接异常";
}
} catch (Exception e) {
resultMsg = "连接异常";
} finally {
// 关闭get
httpget.abort();
// 关闭连接 ,释放资源
httpclient.getConnectionManager().shutdown();
}
return resultMsg;
}

protected static String post(String uri, Object params) {
String resultMsg;
// 设置http请求配置
HttpParams hp = new BasicHttpParams();
hp.setParameter("charset", HTTP.UTF_8);
// 配置连接超时
HttpConnectionParams.setConnectionTimeout(hp, 10 * 1000);
HttpConnectionParams.setSoTimeout(hp, 15 * 1000);
// 实例化HttpClient
HttpClient httpclient = new DefaultHttpClient(hp);
// 实例化HttpPost请求
HttpPost httppost = new HttpPost(uri);
// 设置头信息
httppost.addHeader("Content-Type", "application/json");
httppost.addHeader("charset", HTTP.UTF_8);
try {
// 将参数进行json化
ObjectMapper mapper = new ObjectMapper();
String jsonStr = mapper.writeValueAsString(params);
Log.i(TAG, "URI=" + uri + ",BEAN=" + jsonStr);
// 定义消息实体
StringEntity se = new StringEntity(jsonStr, HTTP.UTF_8);
httppost.setEntity(se);
// 通信
HttpResponse resp = httpclient.execute(httppost);
int statusCode = resp.getStatusLine().getStatusCode();
Log.i(TAG, "StatusCode=" + statusCode);
if (statusCode == HttpStatus.SC_OK) {
StringBuffer result = getResponse(resp);
resultMsg = result.toString();
} else {
resultMsg = "连接异常";
}
} catch (Exception e) {
e.printStackTrace();
resultMsg = "连接异常";
} finally {
// 关闭get
httppost.abort();
// 关闭连接 ,释放资源
httpclient.getConnectionManager().shutdown();
}
Log.i(TAG, resultMsg);
return resultMsg;
}
二、SOCKET连接
服务器端：
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class service_java_test {
public static void main(String[] args) throws IOException {
ServerSocket server = new ServerSocket(10000); //绑定的端口号
Socket socket = server.accept(); //连接不成功以至于下一行的"连接成功"
//在调试区显示不出来
System.out.println("连接成功");
BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
PrintWriter out = new PrintWriter(socket.getOutputStream());
while (true) {
String msg = in.readLine();
System.out.println(msg);
out.println("Server received " + msg); //向接收方发送已接受到了的语句
out.flush();
if (msg.equals("bye")) { //若接收到"bye"则break
break;
}
}
socket.close();
}
}

安卓客户端：
package com.example.t4_android;
import java.net.Socket;
import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;
public class MainActivity extends Activity {
private TextView myTextView;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myTextView = (TextView) findViewById(R.id.textView1);
Thread t = new Thread(new Runnable(){
public void run(){
try {
Socket sk = new Socket("192.168.253.1", 10000);//绑定套接字，这一行一直执行不成功
//以至于下一行在安卓页面的TextView上
//不显示“已连接”的字样
//"192.168.253.1"是我利用DOS命令查找
//的本机IP
myTextView.setText("已连接");
} catch (Exception e) {
e.printStackTrace();
}
}
});
t.start();
}
}

③ android 连接webservice问题.急急急急急急

目测是com.ctc.wstx.exc.WstxIOException这宏尺个异常，有null值。还有客困如户汪绝启端中断