我正在尝试连接android eclipse中的mysql数据库并且也在使用 mysql-connector-java-3.1.12-bin。 但它向我显示了一条消息：由于潜在的异常导致的失败。 并且它还没有连接我使用相同的东西将netbeans连接到我的Java程序。 任何帮助将不胜感激。
package com.bookapp;
import java.sql.SQLException;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.Toast;
import android.app.Activity;
import android.content.Intent;
public class PersonalInfo extends Activity {
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.personalinfo);
try
{
StudentDA stud= new StudentDA();
for (String jshdjsd: stud.GetAllUniversities()) {
Toast tt=Toast.makeText(PersonalInfo.this, jshdjsd,Toast.LENGTH_LONG);
tt.show();
}
//for eastud.GetAllUniversities()));
}
catch(SQLException ss)
{
Toast tt=Toast.makeText(PersonalInfo.this, "You have an Error "+ss.getMessage(),Toast.LENGTH_LONG);
tt.show();
}
//create reference to layout widget/control
Button btnNext=(Button) findViewById(R.id.btnNext);
//create reference to textbox
final EditText txtStudNo,txtName,txtSurname; // text box
final Spinner cmbGender=(Spinner) findViewById(R.id.cmbGender); // combo box
txtStudNo=(EditText) findViewById(R.id.txtStudentNo);
txtName=(EditText) findViewById(R.id.txtName);
txtSurname=(EditText) findViewById(R.id.txtSurname);
//set the button onclick event listener
btnNext.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
if (txtStudNo.getText().toString().equals(""))
{
Toast tt=Toast.makeText(PersonalInfo.this, "Please Enter Student No", Toast.LENGTH_LONG);
tt.show();
}
else if (txtName.getText().toString().equals(""))
{
Toast tt=Toast.makeText(PersonalInfo.this, "Please Enter Name", Toast.LENGTH_LONG);
tt.show();
}
else if (txtSurname.getText().toString().equals(""))
{
Toast tt=Toast.makeText(PersonalInfo.this, "Please Enter Surname", Toast.LENGTH_LONG);
tt.show();
}
else if (cmbGender.getSelectedItemPosition()==0)
{
Toast tt=Toast.makeText(PersonalInfo.this, "Please Select Gender", Toast.LENGTH_LONG);
tt.show();
}
else
{
Student.Gender=cmbGender.getSelectedItem().toString();
Student.studentNo=txtStudNo.getText().toString();
Student.Name=txtName.getText().toString();
Student.Surname=txtSurname.getText().toString();
// Go to the next form
Intent i = new Intent (PersonalInfo.this,ContactInfo.class);
startActivity(i);
//////End of me next
//Toast tt=Toast.makeText(PersonalInfo.this, "Thanks "+ Student.Name, Toast.LENGTH_LONG);
// tt.show();
}
}
});
}
}
答案 0 :(得分：0)
您无法将mysql数据库与android连接。您可以使用webservices来调用数据库。 Web服务的一些示例是SOAP和RESTFUL。您可以使用其中任何一个来调用db。
请参阅以下示例以调用webservice： http://programmerguru.com/android-tutorial/android-restful-webservice-tutorial-how-to-call-restful-webservice-in-android-part-3/
您可以使用SQL Lite在andorid中创建mini db。谷歌在SQL Lite上获取更多细节。
答案 1 :(得分：0)
在Eclipse中创建一个java项目
创建包名称com.example.sql
在项目中加入mysqlconnector.jar
本地系统的代码
package com.example.employeeinduction;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.ArrayList;
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.apache.http.params.BasicHttpParams;
import org.apache.http.params.HttpConnectionParams;
import org.apache.http.params.HttpParams;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.SharedPreferences;
import android.nfc.Tag;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
public class MainActivity extends Activity
{
public EditText uname,pwd;
Button btnlog1;
TextView invalid;
public Button btncancel1;
public String db_select;
String mUname;
String mPwd;
String temp;
Intent intObj;
Intent intent = null;
SessionManager session;
Boolean isInternetPresent = false;
ConnectionDetector cd;
private String SERVICE_URL = "http://10.54.3.208:8080/";
private final String SERVICE_URL = Urlmanager.Address;
private final String TAG = "MainActivity";
public static final String PREFS_NAME = "MyPrefsFile";
public static final String Is_Login = "Is_Login";
public static final String MyPREFERENCES = "MyPREFERENCES";
private static final String IS_USER_LOGIN = "IsUserLoggedIn";
@Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
MainActivity.this.setContentView(R.layout.activity_main);
uname=(EditText)findViewById(R.id.editText1);
pwd=(EditText)findViewById(R.id.editText2);
invalid=(TextView)findViewById(R.id.textView3);
btnlog1=(Button)findViewById(R.id.button1);
session = new SessionManager(getApplicationContext());
btnlog1.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
mUname=uname.getText().toString();
mPwd=pwd.getText().toString();
String d="true";
SharedPreferences prefs = getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor editor = prefs.edit();
editor.putString("Is_Login",d);
editor.putString("EMP_ID",mUname);
editor.putString("EMP_PWD",mPwd);
editor.commit();
if(!mUname.equalsIgnoreCase("") && !mPwd.equalsIgnoreCase(""))
{
cd = new ConnectionDetector(getApplicationContext());
isInternetPresent = cd.isConnectingToInternet();
//Toast.makeText(MainActivity.this, isInternetPresent, Toast.LENGTH_LONG).show();
if(isInternetPresent)
{
try
{
validat_user(mUname,mPwd);
session.createLoginSession(mUname,mPwd);
}
catch(Exception e)
{
display("Network error.\nPlease check with your network settings.");
uname.setText("");
pwd.setText("");
}
}
else
{
display("No Internet Connection...");
}
}
else
{
invalid.setText("Please enter the data");
}
}
});
}
/*@Override
protected void onResume()
{
SharedPreferences sharedpreferences=getSharedPreferences(MyPREFERENCES,
Context.MODE_PRIVATE);
if (sharedpreferences.contains(mUname))
{
if(sharedpreferences.contains(mPwd)){
Intent i = new Intent(this,Design_Activity.class);
startActivity(i);
}
}
super.onResume();
}*/
public void display(String msg)
{
Toast.makeText(MainActivity.this, msg, Toast.LENGTH_LONG).show();
}
private void validat_user(String stg1, String stg2)
{
db_select=stg1;
WebServiceTask wst = new WebServiceTask(WebServiceTask.POST_TASK, this, "Login in progress...");
wst.addNameValuePair("EMP_ID", stg1);
wst.addNameValuePair("EMP_PWD", stg2);
wst.execute(new String[] { SERVICE_URL });
}
@SuppressWarnings("deprecation")
public void no_net()
{
display( "No Network Connection");
final AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this).create();
alertDialog.setTitle("No Internet Connection");
alertDialog.setMessage("You don't have internet connection.\nElse please check the Internet Connection Settings.");
//alertDialog.setIcon(R.drawable.error_info);
alertDialog.setCancelable(false);
alertDialog.setButton("Close", new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int which)
{
alertDialog.cancel();
MainActivity.this.finish();
System.exit(0);
}
});
alertDialog.setButton2("Use Local DataBase", new DialogInterface.OnClickListener()
{
public void onClick(DialogInterface dialog, int which)
{
display( "Accessing local DataBase.....");
alertDialog.cancel();
}
});
alertDialog.show();
}
private class WebServiceTask extends AsyncTask<String, Integer, String> {
public static final int POST_TASK = 1;
private static final String TAG = "WebServiceTask";
// connection timeout, in milliseconds (waiting to connect)
private static final int CONN_TIMEOUT =12000;
// socket timeout, in milliseconds (waiting for data)
private static final int SOCKET_TIMEOUT =12000;
private int taskType = POST_TASK;
private Context mContext = null;
private String processMessage = "Processing...";
private ArrayList<NameValuePair> params = new ArrayList<NameValuePair>();
private ProgressDialog pDlg = null;
public WebServiceTask(int taskType, Context mContext, String processMessage) {
this.taskType = taskType;
this.mContext = mContext;
this.processMessage = processMessage;
}
public void addNameValuePair(String name, String value) {
params.add(new BasicNameValuePair(name, value));
}
@SuppressWarnings("deprecation")
private void showProgressDialog() {
pDlg = new ProgressDialog(mContext);
pDlg.setMessage(processMessage);
pDlg.setProgressDrawable(mContext.getWallpaper());
pDlg.setProgressStyle(ProgressDialog.STYLE_SPINNER);
pDlg.setCancelable(false);
pDlg.show();
}
@Override
protected void onPreExecute() {
showProgressDialog();
}
protected String doInBackground(String... urls) {
String url = urls[0].toString();
String result = "";
HttpResponse response = doResponse(url);
if (response == null) {
return result;
} else {
try {
result = inputStreamToString(response.getEntity().getContent());
} catch (IllegalStateException e) {
Log.e(TAG, e.getLocalizedMessage(), e);
} catch (IOException e) {
Log.e(TAG, e.getLocalizedMessage(), e);
}
catch(Exception e)
{
Log.e(TAG, e.getLocalizedMessage(), e);
}
}
return result;
}
@Override
protected void onPostExecute(String response) {
handleResponse(response);
pDlg.dismiss();
}
// Establish connection and socket (data retrieval) timeouts
private HttpParams getHttpParams() {
HttpParams htpp = new BasicHttpParams();
HttpConnectionParams.setConnectionTimeout(htpp, CONN_TIMEOUT);
HttpConnectionParams.setSoTimeout(htpp, SOCKET_TIMEOUT);
return htpp;
}
private HttpResponse doResponse(String url) {
// Use our connection and data timeouts as parameters for our
// DefaultHttpClient
HttpClient httpclient = new DefaultHttpClient(getHttpParams());
HttpResponse response = null;
try {
switch (taskType) {
case POST_TASK:
HttpPost httppost= new HttpPost(url);
httppost.setEntity(new UrlEncodedFormEntity(params));
response = httpclient.execute(httppost);
break;
}
}
catch (Exception e) {
// display("Remote DataBase can not be connected.\nPlease check network connection.");
Log.e(TAG, e.getLocalizedMessage(), e);
return null;
}
return response;
}
private String inputStreamToString(InputStream is) {
String line = "";
StringBuilder total = new StringBuilder();
// Wrap a BufferedReader around the InputStream
BufferedReader rd = new BufferedReader(new InputStreamReader(is));
try {
// Read response until the end
while ((line = rd.readLine()) != null) {
total.append(line);
}
} catch (IOException e) {
Log.e(TAG, e.getLocalizedMessage(), e);
}
catch(Exception e)
{
Log.e(TAG, e.getLocalizedMessage(), e);
}
// Return full string
return total.toString();
}
}
public void handleResponse(String response)
{
//display("Response:"+response);
if(!response.equalsIgnoreCase(""))
{
JSONObject jso;
try {
jso = new JSONObject(response);
String status = jso.getString("status");
int valid=jso.getInt("valid");
// display("Welcome : "+UName);
if(valid>0)
{
if( status.equalsIgnoreCase("") || status==null || status.equalsIgnoreCase("Failed"))
{
invalid.setText("Invalid password");
//reset();
pwd.setText("");
}
else
{
//session.createLoginSession(mUname,mPwd);
//display(status);
intObj=new Intent(MainActivity.this,Design_Activity.class);
startActivity(intObj);
MainActivity.this.finish();
}
}
else
{
invalid.setText("Invalid userid");
uname.setText("");
}
}
catch (JSONException e1) {
Log.e(TAG, e1.getLocalizedMessage(), e1);
}
catch(Exception e)
{
Log.e(TAG, e.getLocalizedMessage(), e);
}
}
else
{
display("Could not able to reach Server!");
}
}
public void reset()
{
pwd.setText("");
uname.setText("");
}
}