android - 使用 XML 填充 SQLite 并集成到 Activity 中

Question

在我找到的所有教程(包括 Stackoverflow 中的答案)中，我找不到一个完整 教程来展示如何实现 XML 到 SQLite 的填充。我创建了一个数据库助手，但我不知道如何将它集成到我的 Activity 中。我想做的是；一旦应用程序启动，它就应该用 XML 填充数据库。

XML

我在“res\xml”文件夹中有一个 XML 文件“amawal_posts.xml”，其中包含一些我想填充到数据库中的条目。

<?xml version="1.0" encoding="utf-8"?>
<database name="npma_amawal" >
    <!-- Table wp_posts -->
    <table name="wp_posts" >
        <column name="ID" >948</column>
        <column name="post_content" >اورغ</column>
        <column name="post_title" >ure</column>
    </table>
    <table name="wp_posts" >
        <column name="ID" >46</column>
        <column name="post_content" >adlis g llan iwaliwn FR: dictionnaire.</column>
        <column name="post_title" >amawal</column>
    </table>
</database>

此 XML 包含超过 4000 条记录。

SQLiteOpenHelper

这是“XMLtoSQLite.java”的内容

package com.np.amawalandroiddb;

import java.io.IOException;

import org.xmlpull.v1.XmlPullParserException;

import com.np.amawalandroiddb.R;

import android.content.ContentValues;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.XmlResourceParser;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;

public class XMLtoSQLite extends SQLiteOpenHelper {

    private final Context fContext;

    // Set TAG for error catching
    public static String TAG = "XMLtoSQLite";

    // Set database columns
    public static String column_ID = null;
    public static String column_post_content = null;
    public static String column_post_title = null;

    public XMLtoSQLite(Context context) {
        super(context, "amawal", null, 1);
        fContext = context;
    }


    public void createDataBase (SQLiteDatabase db) throws IOException {
        db.execSQL("CREATE TABLE amawal_posts (" + "ID INTEGER PRIMARY KEY,"
                + "post_content TEXT," + "post_content TEXT" + ");");

        // Add default records amawal_posts
        ContentValues Columns = new ContentValues();

        // Get XML resource file
        Resources res = fContext.getResources();

        // Open XML file
        int eventType = -1;
        while (eventType != XmlResourceParser.END_DOCUMENT) {
            XmlResourceParser database = res.getXml(R.xml.amawal_posts);
            String name = database.getText();
            Log.d(TAG, name);

            try {
                if (database.getEventType() == XmlResourceParser.START_TAG) 
                {
                    String s = database.getName();

                    if (s.equals("table")) 
                    {
                        database.next(); // moving to the next node
                        if (database.getName() != null  && database.getName().equalsIgnoreCase ( "column")) 
                        {
                            column_ID = database.getText(); // to get  value getText() method should be used
                            database.next();

                            column_post_content = database.getText();
                            database.next();

                            column_post_title = database.getText(); 

                            // Insert the values inside the DB
                            Columns.put("ID", column_ID);
                            Columns.put("post_content", column_post_content);
                            Columns.put("post_title", column_post_title);

                            db.insert("amawal", null, Columns);

                        }

                        Log.d(TAG, column_ID);
                        Log.d(TAG, column_post_content);
                        Log.d(TAG, column_post_title);
                    }
                }
            } 
            //Catch errors
            catch (XmlPullParserException e)
            {       
                Log.e(TAG, e.getMessage(), e);
            }
            catch (IOException e)
            {
                Log.e(TAG, e.getMessage(), e);

            }           
            finally
            {           
                //Close the XML file
                database.close();
            }
        }
    }

    /* Update database to latest version */
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // Crude update, make sure to implement a correct one when needed.

        Log.w(TAG, "Upgrading database from version " + oldVersion + " to "
                + newVersion + ", which will destroy all old data");
        db.execSQL("DROP TABLE IF EXISTS animals");
        onCreate(db);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // TODO Auto-generated method stub

    }

}

我的主要 Activity

“MainActivity.java”的内容

package com.np.amawalandroiddb;


import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class MainActivity extends Activity {

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

        // Begin DB work
        XMLtoSQLite db = new XMLtoSQLite(this);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}

作为 Java 编程的初学者， Activity/布局/服务之间的关系..有点难以理解:(

问题:如何在我的 Activity 中调用/执行它？

Answer 1

createDataBase() 方法应该在 XMLtoSQLite 类的 onCreate() 方法中调用