谁能告诉我在哪里可以找到一个简单的教程，该教程展示了如何制作一个连接到外部 MySQL 数据库的 Android 应用程序，并报告一些数据？
我在 Internet 上找到的教程并不准确 - 它们不起作用或代码不完整。
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;
import android.widget.Toast;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.HttpClient;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.methods.HttpRequestBase;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.message.BasicNameValuePair;
import android.preference.PreferenceActivity;
import android.preference.PreferenceManager;
import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.EditText;
import android.widget.TextView;
public class main extends Activity {
/** Called when the activity is first created. */
Button login;
String name = "", pass = "";
EditText username, password;
TextView tv;
byte[] data;
HttpPost httppost;
StringBuffer buffer;
HttpResponse response;
HttpClient httpclient;
InputStream inputStream;
SharedPreferences app_preferences;
List<NameValuePair> nameValuePairs;
CheckBox check;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
app_preferences = PreferenceManager.getDefaultSharedPreferences(this);
username = (EditText) findViewById(R.id.username);
password = (EditText) findViewById(R.id.password);
login = (Button) findViewById(R.id.login);
check = (CheckBox) findViewById(R.id.check);
String Str_user = app_preferences.getString("username", "0");
String Str_pass = app_preferences.getString("password", "0");
String Str_check = app_preferences.getString("checked", "no");
if (Str_check.equals("yes")) {
username.setText(Str_user);
password.setText(Str_pass);
check.setChecked(true);
}
login.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
name = username.getText().toString();
pass = password.getText().toString();
String Str_check2 = app_preferences.getString("checked", "no");
if (Str_check2.equals("yes")) {
SharedPreferences.Editor editor = app_preferences.edit();
editor.putString("username", name);
editor.putString("password", pass);
editor.commit();
}
if (name.equals("") || pass.equals("")) {
Toast.makeText(main.this, "Blank Field..Please Enter",
Toast.LENGTH_LONG).show();
} else {
try {
httpclient = new DefaultHttpClient();
httppost = new HttpPost(
"http://www.****.com/android/check.php");
// Add your data
nameValuePairs = new ArrayList<NameValuePair>(2);
nameValuePairs.add(new BasicNameValuePair("UserEmail",
name.trim()));
nameValuePairs.add(new BasicNameValuePair("Password",
pass.trim()));
httppost.setEntity(new UrlEncodedFormEntity(
nameValuePairs));
// Execute HTTP Post Request
response = httpclient.execute(httppost);
inputStream = response.getEntity().getContent();
data = new byte[256];
buffer = new StringBuffer();
int len = 0;
while (-1 != (len = inputStream.read(data))) {
buffer.append(new String(data, 0, len));
}
inputStream.close();
} catch (Exception e) {
Toast.makeText(main.this, "error" + e.toString(),
Toast.LENGTH_LONG).show();
}
if (buffer.charAt(0) == 'Y') {
Toast.makeText(main.this, "login successfull",
Toast.LENGTH_LONG).show();
} else {
Toast.makeText(main.this,
"Invalid Username or password",
Toast.LENGTH_LONG).show();
}
}
}
});
check.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
// Perform action on clicks, depending on whether it's now
// checked
SharedPreferences.Editor editor = app_preferences.edit();
if (((CheckBox) v).isChecked()) {
editor.putString("checked", "yes");
editor.commit();
} else {
editor.putString("checked", "no");
editor.commit();
}
}
});
}
public void Move_to_next() {
// startActivity(new Intent(this, zzz.class));
}
}