如何将数据从 servlet 传递到 android 应用程序
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【中文标题】如何将数据从 servlet 传递到 android 应用程序【英文标题】：how to pass data from servlet to android application 【发布时间】：2011-06-11 14:46:51 【问题描述】：I have a form in android upon submit im inserting it into database using servlet i have to show to user that form was inserted successfully. this is my application
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.Statement;
import java.util.ArrayList;
/**
*
* @author trainee
*/
public class form extends HttpServlet
String name;
String password;
Connection con = null;
Statement stmt = null;
/**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
/* TODO output your page here
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet form</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>Servlet form at " + request.getContextPath () + "</h1>");
out.println("</body>");
out.println("</html>");
*/
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
try
catch(Exception ex)
/**
* Handles the HTTP <code>POST</code> method.
* @param request servlet request
* @param response servlet response
* @throws ServletException if a servlet-specific error occurs
* @throws IOException if an I/O error occurs
*/
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException
try
Class.forName("com.mysql.jdbc.Driver");
con =DriverManager.getConnection ("jdbc:mysql://localhost:3306/Login","root", "");
String nn=request.getParameter("name");
String pass=request.getParameter("pass");
String email=request.getParameter("email");
stmt=con.createStatement();
String query="insert into users values('"+nn+"','"+pass+"','"+email+"');";
int v=stmt.executeUpdate(query);
ArrayList<String> arr=new ArrayList<String>();
arr.add("inserted");
System.out.println("sent response back...");
catch(Exception ex)
/**
* Returns a short description of the servlet.
* @return a String containing servlet description
*/
@Override
public String getServletInfo()
return "Short description";
// </editor-fold>
这是我的安卓应用程序
package org.me.loginandroid;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.io.*;
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.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONObject;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import org.apache.http.client.methods.HttpGet;
public class MainActivity extends Activity
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button btn1 = (Button) findViewById(R.id.submit);
btn1.setOnClickListener(listener_login);
private OnClickListener listener_login = new OnClickListener()
boolean check = false;
public void onClick(View v)
EditText emailText = (EditText) findViewById(R.id.email);
EditText passText = (EditText) findViewById(R.id.password);
EditText nameText = (EditText) findViewById(R.id.uname);
String name = nameText.getText().toString();
String email = (emailText.getText().toString());
String pass = (passText.getText().toString());
String result = "";
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>();
nameValuePairs.add(new BasicNameValuePair("name", name));
nameValuePairs.add(new BasicNameValuePair("pass", pass));
nameValuePairs.add(new BasicNameValuePair("email", email));
try
HttpClient httpclient = new DefaultHttpClient();
HttpPost httppost = new HttpPost("http://10.0.2.2:8084/Login/form");
httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
HttpResponse response = httpclient.execute(httppost);
HttpEntity entity = response.getEntity();
InputStream is = entity.getContent();
BufferedReader reader = new BufferedReader(new InputStreamReader(is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null)
sb.append(line + "\n");
is.close();
result = sb.toString();
TextView lbl = (TextView) findViewById(R.id.lbl);
lbl.setText(result);
catch (Exception e)
TextView tv = (TextView) findViewById(R.id.err);
tv.setText("Error parsing data " + e.toString());
System.out.println("Error parsing data " + e.toString());
//parse json data
try
boolean check=false;
ArrayList<String> arrays=new ArrayList<String>();
for(int i=0;i<arrays.size();i++)
if(arrays.get(i).equals("Inserted"))
check=true;
else
if(check)
Intent myintent = new Intent(MainActivity.this, welcome.class);
startActivity(myintent);
else
TextView tv = (TextView) findViewById(R.id.err);
tv.setText("Data was not inserted properly");
catch (Exception e)
//setContentView(R.layout.notify);
TextView tv = (TextView) findViewById(R.id.err);
tv.setText(e.toString());
System.out.println("log_tag" + "Error parsing data ");
;
【问题讨论】：
您需要添加更多信息。你是如何提出要求的。 如何在request中添加以及如何在android应用中处理 你能补充一些信息吗？您在寻求什么样的帮助？ 【参考方案1】：您需要为您的 servlet 页面创建一个 URLConnection 并执行此操作。例如：How to download file/image from url to your device
【讨论】：
【参考方案2】：您可以通过json format 将数据从servlet 获取到andriod 应用程序。
请通过此http://wiebe-elsinga.com/blog/?p=405 链接了解如何从 Android 应用程序调用 Servlet 并获得响应
返回 json 格式。
从 Andriod 调用 Servlet
private InputStream callService(String text)
InputStream in = null;
SERVLET_URL = http://wizkid.com/web/updateServlet";
try
URL url = new URL(SERVLET_URL);
URLConnection conn = url.openConnection();
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setRequestMethod("POST");
httpConn.setDoInput(true);
httpConn.setDoOutput(true);
httpConn.connect();
DataOutputStream dataStream = new DataOutputStream(conn
.getOutputStream());
dataStream.writeBytes(text);
dataStream.flush();
dataStream.close();
int responseCode = httpConn.getResponseCode();
if (responseCode == HttpURLConnection.HTTP_OK)
in = httpConn.getInputStream();
catch (Exception ex)
display("Error: Not not connect");
return in;
// 从服务器获取数据到安卓
private String getResultFromServlet(String text)
String result = "";
InputStream in = callService(text);
if (in != null)
JSONObject jsonResponse;
try
jsonResponse = new JSONObject(convertStreamToString(in));
result = jsonResponse.getString("output");
catch (JSONException e)
result = "Error: JSON Object couldn't be made";
else
result = "Error: Service not returning result";
return result;
【讨论】：
【参考方案3】：首先，
如果你的doGet() 和doPost() 做同样的事情，你可以打电话给另一个，发送request 和response
其次，您可以将ArrayList<E> 传递给android 应用程序。
Servlet 和 Android API 都有它
编辑： 您需要从 HttpURLConnection 对象生成的 InputStream 中读取。 http://developer.android.com/reference/java/io/InputStream.html
看看这本书： 旧书http://www.amazon.com/Professional-Android-Application-Development-Programmer/dp/0470565527)
String input = getString(R.string.input);try URL url = new URL(input);URLConnection connection = url.openConnection();HttpURLConnection http = (HttpURLConnection)connection;int response = http.getResponseCode();if (response == HttpURLConnection.HTTP_OK) InputStream is = http.getInputStream();//do whatever you want with the streamcatch (MalformedURLException exception) catch (IOException exception)
【讨论】：
但是如何给android url？？我怎样才能找到它【参考方案4】：您可以在这里查看。有一个完整的示例代码描述
Send arraylist from servlet to Android application
【讨论】：
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