Java Interview 06| Project related introduction

1, clear what your project is to do, what is the function

Ad Delivery Machine: The project is mainly for the mobile end targeted advertising display.

Media Management platform SSP: Implementing multiple monetization approaches for media side

(1) The function of advertisement retrieval and sorting in AD-serving machine

1. Search using Boolean expressions for ad retrieval

Look at the implementation of an inverted index, as follows:

public class Inverseindex<t> extends Hashmap<t, list<integer>> {private static final long Serialversionuid = 1l;public void Add (vector<t> doc, int currdocid) {//Join document is to join the keyword in doc//Traverse all the termfor in document ( int w = 0; W < Doc.size (); w++) {list<integer> result = This.get (Doc.get (w)), if (result = = null) {This.put (Doc.get (w), New arraylist< Integer> ());} This.get (Doc.get (W)). Add (Currdocid); Inserts a new document at the end of the inverted index}}//a query in the index public void retrieve (set<t> query, set<integer> docids) {iterator<t> iterator = Query.iterator (); while (Iterator.hasnext ()) {T t = iterator.next (); if (This.get (T) = null && this.get ( T). Size ()! = 0) {Docids.addall (This.get (t));}}}

When you retrieve an ad, the inverted index faces two problems:

A: The orientation condition combination of advertisement can be regarded as a Boolean expression that is connected with the relationship or relation.

B: When contextual keywords or user tags are rich, the query criteria for ad retrieval may be more.

So use a Boolean expression to do it. It is also divided into two main steps to create an inverted index for ads in the ad library and to find ads in the index that match the user's portrait .

　

2, the sort is mainly according to ECPM (Thousand impressions revenue) Note ECPM is thousands of display revenue, so it is for the media

Home ads first push, API ads mainly look at each API advertising platform in a certain media revenue ecpm.

(2) Anti-cheating in advertising

1. The SDK enables data encryption channels when transmitting data, encrypts each request and return of the advertisement, and adds dynamic parameters for the encryption algorithm.

2, jet lag protection strategy mobile advertising cheating process usually occurs in the click, download, activation three steps, normally each step will have its corresponding time. Generally cheating, fake click and activation is co-exist, he no matter who first who after, met even, so often in time logic is wrong. For example, the activation time is earlier than the click Time or the difference is too short. Create an exception-based jet-lag protection strategy for your ad, set the exception-jet range, and after analyzing the hit-and-activate Slack, Check the time difference setting range, the device that activates the fast conversion is classified as an exception. Note that the download is more than a click escalation, or activation is more than the first to download is wrong. Since the SDK may send two independent escalation requests, Mrs. Boss sets the range of slack. 3, more information verification, such as verifying the existence of the device information (the SDK general initialization will be reported device-related information) 4, to provide a protection strategy based on the exception IP segment, the peak range of the IP number exceeded the set of data, will be anti-cheat function automatically filtered, through a large number of cheat logs found, a period of time, Click or activate the IP too concentrated is the common appearance of data anomalies, advertising technology system will be set in a certain amount of time the number of IP peaks, beyond the set range, will be classified as abnormal data.
(3) SSO Single Sign-on system

With single sign-on consolidation, you can only log in once to enter multiple systems without having to sign in again, which not only leads to a better user experience, but more importantly reduces the risk of security (third-party systems do not need to store passwords) and management consumption.

(4) Advertising API Timing Technology

(5) Design patterns used in the project

A single example of double check and inner class implementation of a single case to master

Prototype mode can be used to describe the deep cloning of objects. The main inheritance cloneable interface, the implementation of cloning methods:

Protected Object Clone () throws Clonenotsupportedexception {...}

Reference blog:

(1) http://blog.csdn.net/lifetragedy/article/details/43817903

(2) Http://blog.csdn.net/jadyer

2, clear the overall structure of your project, in the interview can be clearly drawn to the interviewer to see and clearly point out where to call and how to call

3, clear your module in the entire project location and role and clear what your module used to what technology, better to learn more about the whole project to use what technology

4, how to solve the problems encountered in the project?

5, what research in-depth technology or more satisfactory project?

The principle of struts2, cyclic dependency injection of construction method, etc.

Java Interview 06| Project related introduction