通过HashMap访问Android SQLiteDatabase

时间:2012-05-05 07:54:02

标签: android database sqlite hashmap

我尝试在我的应用中实施SQLiteDatabase来存储数据。但是,我编写了一个测试项目来熟悉SQliteDatabase。它相当简单,但仍然无法正常工作。问题出现在代码(为GoogleAPI 7构建)之后。

SQLiteTestActicity:

package test.sqlite.db;

import test.sqlite.db.lib.DatabaseHandler;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class SQLiteTestActivity extends Activity {

private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_SURENAME = "surename";
private static final String KEY_ADDRESS = "address";
private static final String KEY_PHONE = "phone";
private static final String KEY_UID = "uid";
private static final String KEY_TIME = "time";
private static final String KEY_COUNT = "count";
private static final String KEY_DATE = "date";
private static final String ORDERS_TABLE = "orders";

EditText inputName;
EditText inputSurename;
EditText inputAddress;
EditText inputUID;

Button addUserBTN;
Button getUserDetailsBTN;

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

    final DatabaseHandler db = new DatabaseHandler(getBaseContext());

    inputName = (EditText) findViewById(R.id.inputName);
    inputSurename = (EditText) findViewById(R.id.inputSurename);
    inputAddress = (EditText) findViewById(R.id.inputAddress);
    inputUID = (EditText) findViewById(R.id.inputUID);

    addUserBTN = (Button) findViewById(R.id.addUserBTN);
    addUserBTN.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {

            try {

                String name = inputName.getText().toString();
                String surename = inputSurename.getText().toString();
                String address = inputAddress.getText().toString();
                String uid = inputUID.getText().toString();

                db.addUser(name, surename, address, uid);

                try {

                    Toast.makeText(getApplicationContext(), "Succes!",
                            Toast.LENGTH_LONG).show();
                    System.out.printf(name + "\n" + surename + "\n"
                            + address + "\n" + uid + "\n");

                } catch (NullPointerException e) {
                    e.printStackTrace();
                }
            } catch (NullPointerException e) {
                e.printStackTrace();
            }
        }

    });

    getUserDetailsBTN = (Button) findViewById(R.id.getUserDetailsBTN);
    getUserDetailsBTN.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            try {

                System.out.println(db.getUserDetails().toString());

            } catch (NullPointerException e) {
                e.printStackTrace();
            }

        }

    });

}
}

DatabaseHandler:

package test.sqlite.db.lib;

import java.util.HashMap;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

public class DatabaseHandler extends SQLiteOpenHelper {

private static final int DATABASE_VERSION = 1;
private static final String USER_TABLE = "userT";
static String DATABASE_NAME = "TAXIDB";

private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
private static final String KEY_SURENAME = "surename";
private static final String KEY_ADDRESS = "address";
private static final String KEY_PHONE = "phone";
private static final String KEY_UID = "uid";
private static final String KEY_TIME = "time";
private static final String KEY_COUNT = "count";
private static final String KEY_DATE = "date";
private static final String ORDERS_TABLE = "orders";

public DatabaseHandler(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
    String CREATE_USER_TABLE = "CREATE TABLE IF NOT EXISTS " + USER_TABLE
            + "(" + KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT,"
            + KEY_SURENAME + " TEXT," + KEY_ADDRESS + " TEXT," + KEY_UID
            + " TEXT" + ")";
    db.execSQL(CREATE_USER_TABLE);

//      String CREATE_ORDERS_TABLE = "CREATE TABLE IF NOT EXISTS "
//              + ORDERS_TABLE + "(" + KEY_ID
//              + " INTEGER PRIMARY KEY AUTOINCREMENT," + ")";
//      db.execSQL(CREATE_ORDERS_TABLE);

}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    // TODO Auto-generated method stub

}

public void addUser(String name, String surename, String address, String uid) {
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_NAME, name); // Name
    values.put(KEY_SURENAME, surename); // Surename
    values.put(KEY_ADDRESS, address);
    values.put(KEY_UID, uid);

    // Inserting Row
    db.insert(USER_TABLE, null, values);
    db.close(); // Closing database connection
}

public HashMap<String, String> getUserDetails(){
    HashMap<String,String> user = new HashMap<String,String>();
    String selectQuery = "SELECT  * FROM " + USER_TABLE;

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery(selectQuery, null);
    // Move to first row
    cursor.moveToFirst();
    if(cursor.getCount() > 0){
        user.put("name", cursor.getString(1));
        user.put("surename", cursor.getString(2));
        user.put("address", cursor.getString(3));
        user.put("uid", cursor.getString(4));
    }
    cursor.close();
    db.close();
    // return user
    return user;
}
}

问题:

每当我按下getUserDetailsBTN时,我都会收到以下内容:

logcat的:

 {uid=android.widget.EditText@40523fa8, address=android.widget.EditText@40523418, surename=android.widget.EditText@40522888, name=android.widget.EditText@40520548}

1 个答案:

答案 0 :(得分:1)

替换此部分中的代码

 @Override
    public void onClick(View v) {
        try {

            System.out.println(db.getUserDetails().toString());

        } catch (NullPointerException e) {
            e.printStackTrace();
        }

    }

});`

BY此代码

  @Override
    public void onClick(View v) {
        try {
             HashMap<String,String>user = db.getUserDetails();
             //then loop on the inputs of the cursor inside the hashmap and print them successfully
            System.out.println(db.getUserDetails().toString());

        } catch (NullPointerException e) {
            e.printStackTrace();
        }

    }

});