如何在android sqlite数据库中存储MySQL查询（JSON）？

我想编写代码，以便我的android应用程序可以查询MySQL数据库，然后检索JSON中的数据然后解析。然后我想获取数据并将其插入到SQLite的应用程序本地数据库中。我希望这些数据也可以以设定的频率更新。如何在android sqlite数据库中存储MySQL查询（JSON）？

这是JSON数组和HTTP获取协议活动。

package com.connector; 

import java.io.BufferedReader; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.util.ArrayList; 

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.JSONException; 
import org.json.JSONObject; 

import android.app.Activity; 
import android.os.Bundle; 
import android.util.Log; 
import android.widget.LinearLayout; 
import android.widget.TextView; 


public class whitehat extends Activity { 
/** Called when the activity is first created. */ 

TextView txt; 
@Override 
public void onCreate(Bundle savedInstanceState) { 
super.onCreate(savedInstanceState); 
setContentView(R.layout.main); 
// Create a crude view - this should really be set via the layout resources 
// but since its an example saves declaring them in the XML. 
LinearLayout rootLayout = new LinearLayout(getApplicationContext()); 
txt = new TextView(getApplicationContext()); 
rootLayout.addView(txt); 
setContentView(rootLayout); 

// Set the text and call the connect function. 
txt.setText("Connecting..."); 
//call the method to run the data retreival 
txt.setText(getServerData(KEY_121)); 



} 
public static final String KEY_121 = "http://xx.xx.xxx.xxx/hellomysql/mysqlcon.php"; //i use my real ip here 



private String getServerData(String returnString) { 

InputStream is = null; 

String result = ""; 
//the year data to send 
ArrayList<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(); 
nameValuePairs.add(new BasicNameValuePair("publisher","Penguin Books UK")); 

//http post 
try{ 
     HttpClient httpclient = new DefaultHttpClient(); 
     HttpPost httppost = new HttpPost(KEY_121); 
     httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs)); 
     HttpResponse response = httpclient.execute(httppost); 
     HttpEntity entity = response.getEntity(); 
     is = entity.getContent(); 

}catch(Exception e){ 
     Log.e("log_tag", "Error in http connection "+e.toString()); 
} 

//convert response to string 
try{ 
     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(); 
}catch(Exception e){ 
     Log.e("log_tag", "Error converting result "+e.toString()); 
} 
//parse json data 
try{ 
     JSONArray jArray = new JSONArray(result); 
     for(int i=0;i<jArray.length();i++){ 
       JSONObject json_data = jArray.getJSONObject(i); 
       Log.i("log_tag","id: "+json_data.getInt("id")+ 
         ", isbn: "+json_data.getString("isbn")+ 
         ", title: "+json_data.getString("title")+ 
         ", publisher: "+json_data.getString("publisher") 
       ); 
       //Get an output to the screen 
       returnString += "\n\t" + jArray.getJSONObject(i); 
     } 
}catch(JSONException e){ 
     Log.e("log_tag", "Error parsing data "+e.toString()); 
} 
return returnString; 
}  

}

以下两个是与数据库相关的活动。

package com.example.database; 
import android.content.ContentValues; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.SQLException; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 
import android.util.Log; 
public class DBAdapter { 
public static final String KEY_ROWID = "_id"; 
public static final String KEY_ISBN = "isbn"; 
public static final String KEY_TITLE = "title"; 
public static final String KEY_PUBLISHER = "publisher";  
private static final String TAG = "DBAdapter"; 

private static final String DATABASE_NAME = "books"; 
private static final String DATABASE_TABLE = "titles"; 
private static final int DATABASE_VERSION = 1; 
private static final String DATABASE_CREATE = 
    "create table titles (_id integer primary key autoincrement, " 
    + "isbn text not null, title text not null, " 
    + "publisher text not null);"; 

private final Context context; 

private DatabaseHelper DBHelper; 
private SQLiteDatabase db; 
public DBAdapter(Context ctx) 
{ 
    this.context = ctx; 
    DBHelper = new DatabaseHelper(context); 
} 

private static class DatabaseHelper extends SQLiteOpenHelper 
{ 
    DatabaseHelper(Context context) 
    { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    } 
    @Override 
    public void onCreate(SQLiteDatabase db) 
    { 
     db.execSQL(DATABASE_CREATE);  } 
    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, 
    int newVersion) 
    { 
     Log.w(TAG, "Upgrading database from version " + oldVersion 
       + " to " 
       + newVersion + ", which will destroy all old data"); 
     db.execSQL("DROP TABLE IF EXISTS titles"); 
     onCreate(db); 
    } 
}  

//---opens the database--- 
public DBAdapter open() throws SQLException 
{ 
    db = DBHelper.getWritableDatabase(); 
    return this; 
} 
//---closes the database---  
public void close() 
{ 
    DBHelper.close(); 
} 

//---insert a title into the database--- 
public long insertTitle(String isbn, String title, String publisher) 
{ 
    ContentValues initialValues = new ContentValues(); 
    initialValues.put(KEY_ISBN, isbn); 
    initialValues.put(KEY_TITLE, title); 
    initialValues.put(KEY_PUBLISHER, publisher); 
    return db.insert(DATABASE_TABLE, null, initialValues); 
} 
//---deletes a particular title--- 
public boolean deleteTitle(long rowId) 
{ 
    return db.delete(DATABASE_TABLE, KEY_ROWID + 
    "=" + rowId, null) > 0; 
} 
//---retrieves all the titles--- 
public Cursor getAllTitles() 
{ 
    return db.query(DATABASE_TABLE, new String[] { 
      KEY_ROWID, 
      KEY_ISBN, 
      KEY_TITLE, 
      KEY_PUBLISHER}, 
      null, 
      null, 
      null, 
      null, 
      null); 
} 
//---retrieves a particular title--- 
public Cursor getTitle(long rowId) throws SQLException 
{ 
    Cursor mCursor = 
      db.query(true, DATABASE_TABLE, new String[] { 
      KEY_ROWID, 
      KEY_ISBN, 
      KEY_TITLE, 
      KEY_PUBLISHER 
      }, 
     KEY_ROWID + "=" + rowId, 
     null, 
     null, 
     null, 
     null, 
     null); 
    if (mCursor != null) { 
     mCursor.moveToFirst(); 
    } 
    return mCursor; 
} 
//---updates a title--- 
public boolean updateTitle(long rowId, String isbn, 
String title, String publisher) 
{ 
    ContentValues args = new ContentValues(); 
    args.put(KEY_ISBN, isbn); 
    args.put(KEY_TITLE, title); 
    args.put(KEY_PUBLISHER, publisher); 
    return db.update(DATABASE_TABLE, args, 
        KEY_ROWID + "=" + rowId, null) > 0; 
} 
}

第二个是：

public class DatabaseActivity extends Activity { 
DBAdapter db; 
/** Called when the activity is first created. */ 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
    db = new DBAdapter(this); 
    System.out.println("bool1"); 
    insert(); 
disAll(); 
    //update(); 
    //dis(3); 
    //del(5); 
} 
private void update(){ 

    db.open(); 
if (db.updateTitle(1, 
    "0470285818", 
"C# 2008 Programmer's Reference", 
"Wrox Press")) 
     Toast.makeText(this, "Update successful.", 
      Toast.LENGTH_LONG).show(); 
    else 
     Toast.makeText(this, "Update failed.", 
      Toast.LENGTH_LONG).show(); 
    //------------------- 
    //---retrieve the same title to verify--- 
    Cursor c = db.getTitle(1); 
    if (c.moveToFirst())   
     DisplayTitle(c); 
    else 
     Toast.makeText(this, "No title found", 
     Toast.LENGTH_LONG).show();   
    //-------------------   
db.close(); 

} 
private void insert(){ 

    db.open();   
    long id; 
    id = db.insertTitle(
    "0470285819", 
    "Teach yourself Java", 
    "Wrox");   
    id = db.insertTitle(
    "047017661y", 
    "Professional Windows 07 Gadgets Programming", 
    "Wrox"); 
    System.out.println("bool211"); 
    db.close(); 
} 
private void disAll(){ 

    db.open(); 
/*Cursor c = db.getAllTitles(); 
    if (c.moveToFirst()) 
    { 
     do {   
     System.out.println("bool2"); 
      DisplayTitle(c); 
     } while (c.moveToNext()); 
    } 
    else 
    System.out.println("boo3l");*/ 
    try{ 
Cursor c = db.getAllTitles(); 
     if (c.moveToFirst()) 
     { 
      do {   
System.out.println("bool2"); 
       DisplayTitle(c); 
      } while (c.moveToNext()); 
     } 
    }catch(Exception e){ 
    System.out.println(e); 
    } 
    db.close(); 
} 

private void dis( int j){ 

    db.open(); 
    Cursor c = db.getTitle(j); 
    if (c.moveToFirst())   
     DisplayTitle(c); 
    else 
     Toast.makeText(this, "No title found", 
     Toast.LENGTH_LONG).show(); 
    db.close(); 
}   

private void del( int j){ 

    db.open(); 
    if (db.deleteTitle(j)) 
     Toast.makeText(this, "Delete successful.", 
      Toast.LENGTH_LONG).show(); 
    else 
     Toast.makeText(this, "Delete failed.", 
      Toast.LENGTH_LONG).show();    
    db.close();   
} 
public void DisplayTitle(Cursor c) 
{ 
System.out.println("bool"); 
    Toast.makeText(this, 
      "id: " + c.getString(0) + "\n" + 
      "ISBN: " + c.getString(1) + "\n" + 
      "TITLE: " + c.getString(2) + "\n" + 
      "PUBLISHER: " + c.getString(3), 
      Toast.LENGTH_LONG).show();   
} 
}

如果有人能够帮助这将是大加赞赏。

来源

2011-11-27 Hellboundz

你的getServerData方法将返回一个JSONString。在你的getServerData方法中，你有一个Log Statement，它实际上是解析JSONObject。而不是记录它可以调用dbAdapter类中的insertTitle。

为了使这项工作你必须做一些改变。 Ur DBAdapter构造函数应该看起来像这样

public DBAdapter(Context ctx) 
    { 
     this.context = ctx; 
     DBHelper = new DatabaseHelper(context); 
     this.db=DBHelper.getWritableDatabase(); 
    }

Ur创建语句应该看起来像这样。从服务器获取ID。所以没有必要将自动增量设为id。

private static final String DATABASE_CREATE = 
    "create table titles (_id integer primary key , " 
    + "isbn text not null, title text not null, " 
    + "publisher text not null);";

Ur insertTitle应该是这样的。同样改变你的更新和其他方法。

public long insertTitle(String _id,String isbn, String title, String publisher) 
{ 
    ContentValues initialValues = new ContentValues(); 
    initialValues.put(KEY_ID, _id); 
    initialValues.put(KEY_ISBN, isbn); 
    initialValues.put(KEY_TITLE, title); 
    initialValues.put(KEY_PUBLISHER, publisher); 
    return db.insert(DATABASE_TABLE, null, initialValues); 
}

但请确保您在for循环之外创建了dbAdapter对象。希望这会有所帮助

来源

2011-11-28 09:05:45 SurRam

你将如何去调用insertText到getServerData？ – Hellboundz

在whitehat类中执行下面的公共DBAdapter dbAdapter = new DBAdapter（this）。将getServerData中的log.i语句替换为dbAdapter.insertTitle（json_data.getInt（“id”），json_data.getString（“isbn”），json_data.getString（“title”），json_data.getString（“publisher”））; – SurRam

我已经完成了你的建议，但在调试应用程序时，它会抛出一条错误消息并暂停主要活动。无论如何你知道在哪里解决这个问题吗？ – Hellboundz

如何在android sqlite数据库中存储MySQL查询（JSON）？

回答

相关问题