本地机器上使用Android和MySQL的通信链路故障，API 19，Android 4.4.2

我的应用程序运行正常，直到我将eclipse从开普勒升级到6月份，ADT插件从API 17升级到API 19，MySQL JDCB Java Conctor从5.1.26升级到5.1.29

现在我在尝试创建到DB的连接时遇到通信链路故障错误。不同版本之间有什么变化吗

我已经检查了很多次我的代码，但都是好的。但我也在这里复制

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import com.example.pruebaconn.R;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;


public class MainConn extends Activity {

private String mEmail = "";
private String mPassword = "";
private String mReserveCode = "";

// UI references.

private EditText mEmailView;
private EditText mPasswordView;
private EditText mReserveCodeView;

static String urlConMySQL = "jdbc:mysql://10.0.2.2:3306/journey_app";
static String userMySQL = "root";
static String passwordMySQL = "XXXXX";  // Password intentionally hidden

static public Connection mainConnectionMySQL;
static public Statement st;

public Context context;

private boolean userOK = false;


@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    // Set up the login form.

    context = getApplicationContext();

    mEmailView = (EditText) findViewById(R.id.login_email);
    mEmailView.setText(mEmail);

    mPasswordView = (EditText) findViewById(R.id.login_password);
    mPasswordView.setText(mPassword);

    findViewById(R.id.login_button_sign_in).setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            attemptLogin();
        }
    });


}

public void attemptLogin() {

    // Reset errors.
    mEmailView.setError(null);
    mPasswordView.setError(null);

    // Store values at the time of the login attempt.
    mEmail = mEmailView.getText().toString();
    mPassword = mPasswordView.getText().toString();

    userOK = validateUserPassword(mEmail, mPassword);
}

public boolean validateUserPassword (String appU, String pass) {

    boolean userOK = false;

    try {

        userOK = userPasswordValidation(appU, pass);

    } catch (Exception e) {


    }

    return userOK;
}

public Boolean userPasswordValidation (String user, String password) throws Exception {

    Boolean userExists = false;
    String sqlValidaUserPassword;

    sqlValidaUserPassword = "" +
            " SELECT CAST(COUNT(*) > 0 AS CHAR) USER_EXIST_FLAG " +
            " FROM APP_USER " +
            " WHERE APP_USER_ID = '" + user + "' " +
            " AND APP_USER_PASSWORD = '" + password + "'";  

    try {

        createConnection();
        PreparedStatement ps = mainConnectionMySQL.prepareStatement(sqlValidaUserPassword);
        ResultSet rs = ps.executeQuery(sqlValidaUserPassword);
        while (rs.next()) {
            userExists = rs.getBoolean(1);
        }
        rs.close();
        ps.close();

    } catch (Exception e) {

        Toast.makeText(context, "Error " + e.getMessage(), Toast.LENGTH_SHORT).show();
        throw e;

    } finally {

        closeConnection();

    }

    return userExists;

}

public void createConnection () // throws InstantiationException, IllegalAccessException, ClassNotFoundException
{
    try {

        Class.forName("com.mysql.jdbc.Driver");
        mainConnectionMySQL = DriverManager.getConnection(urlConMySQL,userMySQL, passwordMySQL);
        st = mainConnectionMySQL.createStatement();

    } catch (ClassNotFoundException e) {

        Toast.makeText(context, e.getMessage(), Toast.LENGTH_SHORT).show();

    } catch (SQLException e) {

        Toast.makeText(context, e.getMessage(), Toast.LENGTH_SHORT).show();
    }
}

public void closeConnection () 
{
    try {

        if (st != null) {
            mainConnectionMySQL.close();
        }
        if (mainConnectionMySQL != null) {
            mainConnectionMySQL.close();
        }

    } catch (SQLException e) {        

        Toast.makeText(context, e.getMessage(), Toast.LENGTH_SHORT).show();

    }
} 

---

}

开普勒至六月-？你是说朱诺对开普勒？或者你降级了？第一：在android上使用jdbc是一个非常糟糕的主意，第二：你在主线程上进行网络操作。它在3、4天前运行正常，但升级到4.4.2后，已经坏了。。。我已重新安装所有，但它不运行