联系人ProfileProvider - JAVA

ProfileProvider继承自AbstractContyactsProvider。

[java] package com.android.providers.contacts;

import android.content.ContentValues;
import android.content.Context;
import android.content.res.AssetFileDescriptor;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.net.Uri;

import java.io.FileNotFoundException;
import java.util.Locale;

/**
* Simple content provider to handle directing profile-specific calls against a separate
* database from the rest of contacts.
*/
public class ProfileProvider extends AbstractContactsProvider {

private static final String READ_PERMISSION = "android.permission.READ_PROFILE";
private static final String WRITE_PERMISSION = "android.permission.WRITE_PROFILE";

// The Contacts provider handles most of the logic - this provider is only invoked when the
// URI belongs to a profile action, setting up the proper database.
private final ContactsProvider2 mDelegate;

public ProfileProvider(ContactsProvider2 delegate) {
mDelegate = delegate;
}

/**
* Performs a permission check on the read profile permission. Checks the delegate contacts
* provider to see whether this is an authorized one-time-use URI.
* @param uri The URI being accessed.
*/
public void enforceReadPermission(Uri uri) {//检查是否有读权限
if (!mDelegate.isValidPreAuthorizedUri(uri)) {
mDelegate.getContext().enforceCallingOrSelfPermission(READ_PERMISSION, null);
}
}

/**
* Performs a permission check on the write profile permission.

*/
public void enforceWritePermission() {//检查是否有写权限
mDelegate.getContext().enforceCallingOrSelfPermission(WRITE_PERMISSION, null);
}
/**
* 重写getDatabaseHelper，父类的方法
*/
@Override
protected ProfileDatabaseHelper getDatabaseHelper(Context context) {
return ProfileDatabaseHelper.getInstance(context);
}

@Override
protected ThreadLocal getTransactionHolder() {//得到线程本地存储的对象
return mDelegate.getTransactionHolder();
}

@Override
public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs,
String sortOrder) {
enforceReadPermission(uri);//检查权限，如果没有权限抛出异常
mDelegate.substituteDb(getDatabaseHelper().getReadableDatabase());//替换数据库 profile.db
return mDelegate.queryLocal(uri, projection, selection, selectionArgs, sortOrder, -1);
}

@Override
protected Uri insertInTransaction(Uri uri, ContentValues values) {
enforceWritePermission();//检查写权限，如果不存在权限，抛出异常
useProfileDbForTransaction();//启动触发器，并切换数据库到profile.db
return mDelegate.insertInTransaction(uri, values);
}

@Override
protected int updateInTransaction(Uri uri, ContentValues values, String selection,
String[] selectionArgs) {
enforceWritePermission();//检查写权限，如果不存在权限，抛出异常
useProfileDbForTransaction();//启动触发器，并切换数据库到profile.db
return mDelegate.updateInTransaction(uri, values, selection, selectionArgs);
}

@Override
protected int deleteInTransaction(Uri uri, String selection, String[] selectionArgs) {
enforceWritePermission();//检查写权限，如果不存在权限，抛出

联系人ProfileProvider (一)