玩转Android Provider

参考：http://blog.youkuaiyun.com/yan8024/article/details/6444368



package com.HelloWorld;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;

import android.content.ContentProvider;
import android.content.ContentValues;
import android.content.Context;
import android.content.UriMatcher;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;
import android.os.Environment;

public class MyProvider extends ContentProvider {

	
	private final static String DB_DIR = "lp";
	private final static String DB_NAME = "contacts.db";
	private final static String TABLE_NAME = "PRMContacts";
	private Context mContext;
	private SQLiteDatabase db ;
	private  static  final  String AUTHORITY = "com.helloword.myprovider" ;
	private  static  UriMatcher uriMatcher;  
	private  static  final  int  ONE = 1 ;  
	private  static  final  int  MORE = 2 ;  
	static   
    {  
        //  添加访问ContentProvider的Uri   
        uriMatcher = new  UriMatcher(UriMatcher.NO_MATCH);  
        uriMatcher.addURI(AUTHORITY, "one" , ONE);  
        uriMatcher.addURI(AUTHORITY, "more/*" , MORE);  
    }  
	
	@Override
	public int delete(Uri uri, String selection, String[] selectionArgs) {
		// TODO Auto-generated method stub
		return 0;
	}

	@Override
	public String getType(Uri uri) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public Uri insert(Uri uri, ContentValues values) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public boolean onCreate() {
		mContext = getContext();
		db = openDatabase();
		return true;
	}

	@Override
	public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
		Cursor cursor = null;
		System.out.println("query");
		switch(uriMatcher.match(uri)){
			case ONE:
				cursor = db.query(TABLE_NAME, projection, selection, selectionArgs, null, null, sortOrder);
				break;
			case MORE:
				String word = uri.getPathSegments().get(1);
				cursor = db.rawQuery("select * from "+TABLE_NAME+" where displayname like ?", new String[]{word+"%"});
				break;
			default:
				throw new IllegalArgumentException("无效参数");
		}
		return cursor;
	}

	@Override
	public int update(Uri uri, ContentValues values, String selection, String[] selectionArgs) {
		// TODO Auto-generated method stub
		return 0;
	}
	
	 private SQLiteDatabase openDatabase()
	    {
        	if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
        		FileOutputStream fos = null;
        		InputStream is = null;
        		try
    	        {
	        		String path = Environment.getExternalStorageDirectory().getAbsolutePath() + "/"+DB_DIR;
	        		
	        		// 获得dictionary.db文件的绝对路径
		            String databaseFilename = path + "/" + DB_NAME;
		            File dir = new File(path);
		            
		            if(!dir.exists()){
		            	dir.mkdir();
		            }
		            
		            File db = new File(databaseFilename);
		            if(!db.exists()){
		            	fos = new FileOutputStream(db);
		            	is = mContext.getResources().openRawResource(R.raw.contacts);
		            	
		            	byte[] buffer = new byte[1024];
		            	int length = 0;
		            	while((length = is.read(buffer))!=-1){
		            		fos.write(buffer, 0, length);
		            	}
		            }
		            
		            SQLiteDatabase database = SQLiteDatabase.openOrCreateDatabase(databaseFilename, null);
		            return database;
		        }
		        catch (Exception e){
		        	
		        }finally{
		        	if(fos!=null){
		        		try {
							fos.close();
						} catch (IOException e) {
							// TODO Auto-generated catch block
							e.printStackTrace();
						}
		        	}
		        	if(is!=null){
		        		try {
							is.close();
						} catch (IOException e) {
							// TODO Auto-generated catch block
							e.printStackTrace();
						}
		        	}
		        }
        	}
	            
	        return null;
	    }

}