According to their own collection as well as part of his interview he sorted out, I hope to help interview the brothers (2019).
UFIDA network
1, you use micro-services what good is it?
2, the transaction between the micro-services is how to deal with? How to roll back?
3. What MQ use? MQ transaction is how to do?
4, Object there any way? These methods When do you need? equals and hashCode need to be rewritten with me?
5, which is odd how to delete a list. list there are ten integers.
6, Java's IO has no understanding? What are some of the bag?
7, Java's class loading process is what?
8, how to add a method in the Object class? You can do it?
9, how to achieve the Spring framework has no understanding? Loading process the bean, IOC and AOP bottom?
10, Spring inside how to use a transaction? What propagation characteristics of the transaction? For example, a transaction method which reminds one how to write a new transaction?
11, which encodes design patterns used in the process? How to use? Adapter and decorators have to distinguish what is the nature of it?
ZTE financial (outsourcing)
Outsourcing to China CITIC Bank
1, Redis you have a few? How much memory? The maximum capacity of the Redis cluster is the number?
2, ES + Redis integration of operations is how to do? Redis to do so will not have the problem of insufficient memory?
3, product data is resident Redis it? Or are there any strategy?
4, a product search tab is how to do?
5, distributed lock you how to achieve?
6, The data how many? Nikkatsu about how much?
Beijing Bo Rui Tigers
written examination:
1, queue, stack what each feature is?
2, final, final, finalize the difference?
3, HashMap, HashTable, ConcurrentHashMap difference?
4, but the difference between ArrayList and the Vector?
5, to achieve a decimal number string into a string of hexadecimal digits, such as "155" outputs "0x9B." Requirements shall not use any string and numeric conversion method provided by third parties, such as atoi C language, Java's String.parseInt and so on.
6, a simple design objectlist, the SimpleList, given requirements such as: configuration (the SimpleList), read (GET), insertion (INSERT), delete (earse) define basic methods, encourage the use of the template (C ++), or pan type (Java), only asked to write a statement, implementation is not required, please write the necessary comments.
7, given two large random integer to realize calculate the product of two numbers, such as "111111111111111" and "222222222222222", outputs the product "24691358024691308641975308642", the request does not use BigInteger like Java classes.
one side:
1, when it will produce cross-domain? The same port number different domain name involves cross-domain it?
2, several ways to solve cross-domain? spring cross-domain annotations are how to achieve cross-domain?
3, DNS what role?
4, == and equals What is the difference? two new Integer object, the two values are the same, they are == do?
5, the comparison is less than the number can be used between objects larger than it?
6, Java in the long int type type conversion will be a problem?
7, talk about the collection of inheritance?
8, fast ArrayList and HashSet which traverse speed? Find "abc" in this string if the collection, which is faster?
9, HashSet null can put it? .size method and .isEmpty method used? Then put null, size and isEmpty what return?
10,100 new good object, respectively, to put an ArrayList and HashMap, this time the JVM memory size will be doubled occupied it?
11, there are several ways to create a thread? A thread B thread communication and how, if the process is A and B process? Without introducing additional configuration (redis Mq and the like) how communication? Interface can do it? Rpc call wrote it? Http call can do it? Socket Communications wrote it?
12, socket do anything?
13, do a chat software, you will choose what protocol do? Http can be used to do it? What's the problem?
14, Http can do long connections? Long and short connection concept connection is valid? The client sent a request to the server, the server can give you information at any time to return it? Http survival period is how long?
15, Session What is the life cycle?
16, to give you a static HashMap of objects, and open 100 threads entered, put the thread ID, eventually you will get the expected 100 thread ID it?
17, Java, there are a few key lock, what is a deadlock?
18, and when to use recursion? Recursive wording What are the risks?
19, encountered a memory leak it? What happens memory overflow? General Memory Overflow how to solve? Online server memory overflow how to deal with? What tools can monitor? How to analyze?
20. What is your server configuration? Online service configuration know?
21, MySQL there are several join? full join MySql support?
22, MySQL has several data types? What is? What type of increment sequence for? Int length is how much?
23, would fail under what circumstances the index MySQL? What are the common situation?
24, a table has two fields, an id and a phone, the phone field nt type I use, there is an index, if the time to write SQL string types written in quotes will not take the index,
Such write select * from table where phone = '12345678';
25, MysQL have time to update this record, this record did when inserted, this SQL how to write? Oracle can be achieved?
26, MysQL functions and stored procedures written it?
Two faces:
1, the database how you slice selection? Why choose the shardingjdbc?
2, ActiveMQ how did you use? What do you think the scene can get?
3, distributed transactions and data consistency to find out about it? How to implement a distributed transaction?
4, JVM tuning done it? For example, there is a regular service Full GC, how to tune? Often report memory overflow, then how to deal with? How to monitor virtual machine is running it?
5, Redis avalanche how to solve? Cache penetrate it?
6, Redis cluster have done it? Master-slave synchronization is how synchronized? The main library there how to synchronize changes from the library?
7. What is the storage structure of the database indexes? What is the difference between B + and B-Tree Tree is?
8, why B + Tree structure can speed up this query? Full table scan is how to do? Taking the index is how to do?
9, if an index table will be too much a problem?
10, single sign-on is how to do?
11, deep and shallow copy copy What is the difference?
12, packet write a statistical tie score SQL name.
Three sides:
1, C ++ and Java What is the difference?
2, session sharing there are several ways?
3, how to share data between services?
4, Redis data and how the data in the database synchronization?
5. What do you think of projects where technical difficulties?
6, JVM tuning done it?
7, the test environment pressure measuring it? Pressure test results to determine how to meet the requirements? There is no critical pressure, that pressure threshold.
Armored Network
1, to give you a string "abcabccba", write out a way to determine which character first appeared three times?
2, Redis in the RDB and AOF What is the difference? RDB AOF files and how to deal with more and more?
3, AOF rewrite Redis will pause when it?
4, you write what is stored inside the Redis data? What kind of action will lead to cached data updates?
5. You concurrent life? Do you think you need to use the cache?
6, how to maintain data consistency and Redis databases of data? What a scene will cause data inconsistency, how to deal with?
7, MQ how to ensure that no duplication of spending? Is how the message ID generated?
8, the unique ID generated in several ways, zookeep how to achieve self-growth ID?
9, security interfaces is how to ensure the? token validation is how to do?
10, what is the use of code version management? What SVN branch model?
11, Mysql how to solve phantom read?
12, a handwritten SQL: a table has ID 12345, b table has ID 45678, find out how 123?
Mall necessary
Before there is a phone interview, he did not have no written record. The main content is asked Redis and MQ.
one side:
1, talk about your project structure. What do you major in it?
2, make the system work any problems?
3, for high concurrency scenarios and process optimization which are done?
4, what kind of data suitable for caching? What data do you cache? Expires how a given?
5, hash what a key acquisition in which the command is to write about.
6, Redis write a pseudo code is distributed lock.
7, ES combination product search Redis how to achieve? Why not just retrieve information by ES entire goods?
8, under Service A service request initiated by a single B, C deductions service B requests a service inventory, if b c tune timeout (c necessarily failed), how to deal with?
9, SQL optimization are what?
10, write an order query SQL.
11, the number of users? How much UV every day?
12, Integer a = 12; integer b = 12; a == b? == and equals What is the difference?
13, backing HashMap implementation?
Two faces:
1, talk about springAOP, Two Dynamic proxy what's the difference? What is the essence of the difference? Which module uses?
2, distributed lock you specifically talk about is how to use?
3. What design patterns usually used? Lazy and hungry man the difference? Abstract factory and factory method What is the difference?
4, JVM tune of contact before? How tuning?
Chuan Chi podcast
Instructors need to travel frequently. Tutor interview is relatively simple, is to investigate the ability of lectures, will let you go back a recorded video lectures.
Tutor interview:
1, jenkins and k8s
2, the difference shardingjdbc and mycat
3, Redis and penetration avalanche
4, the cache warm-up how to do?
5, springtask and quartz What is the difference?
6, a distributed transaction is how to solve?
7, the monitoring service here is how to do?
8, the difference doubble and springcloud?
9, springboot features, how to achieve?
10, permission authentication framework is how to use?
11, the report did it? poi export file.
Development interview:
1. What common methods are under the Object class?
2, equals and hashcode cover (rewrite) the time to follow the general principles of what?
3, equals overridden method steps? Be sure to override the hashcode it?
4, wait, notify, notifyAll with what scene?
5, collections all know what? Set List and what is the difference?
6, when to use TreeSet? When to Use HashSet? Custom objects into the TreeSet need to override equals you? HashSet into it?
7, TreeSet is how to ensure sortable? How to write two ways comparator?
8, internal HashSet is how to use the equals and hashcode methods.
9, ArrayList and LinkedList What is the difference?
10, Map was put keys on how to ensure the thread safety? HashMap is thread safe?
11, ConcurrentHashMap lower performance than HashMap do?
12, Java IO classes in the inheritance hierarchy? When to use and when inputStream with Reader?
13, write a code that implements the D: \ test.txt Copy the file to the root directory of E.
14, some considerations uploaded files? What types of forms needed to write? What do not deserve, then by default?
15, SpringMVC file upload flow inside how to obtain the file size? Directory is not specified, then the file where the stream will be written?
16, how about when Java exception in the system?
17, checked exception and non-checked exception what's the difference? Abnormal conversion, how to convert a checked exception to a non checked exception? And when thrown by the information search can bring unusual?
18, Http protocol layer belong to what? Http protocol stack sub-layers?
19, Http default port? The default Https port? Difference between the two? SSL in which floor? HTTP and between tcp.
20, Http message request and response structure is kind of how?
21, Http request header common What?
22, Spring AOP and the IOC were to say next?
23, Spring's AOP is how to achieve? Difference JDK dynamic proxies and CGlib of?
24, springboot in Tomcat how to change the port number? In which file, which position?
25, yeml file and propertion difference is what? Note yeml spaces.
26, springboot in propertion custom attributes how to obtain? Several acquisition mode?
27, plus the start of class springboot comment is what?
28, how do you create a new springboot project?
29, springboot and how MyBatis integration? spring it?
30, page MyBatis thinking of?
31, the interface is how to achieve MyBatis interface? Mapper layer of SQL interface call how to achieve? JDK dynamic proxy.
58 city
Department: business intelligence service center
one side:
1, your unique primary key is how to do? uuid how to ensure uniqueness?
2, ES and how product data synchronization? ES has a few servers? How deletions ES server.
3, a single device to log how to achieve?
4, one pair of the subject to write a single embodiment of the lock. Here add volatile so what effect? Here you can lock this?
5, sychronized underlying principle?
6, such as 618 orders suddenly large, what measures are you?
7, how to achieve a long connection?
8, how to filter requests?
Two faces:
1, Synchronized locking process? Underlying how to achieve?
2, load balancing ways?
3, how to achieve a random number algorithm? No Java provides.
4, thread life cycle, starting two threads happen?
5, a SQL reasons for slow implementation, how to solve. SQL condition wording in question, there may be an implicit conversion, did not take the index.
varchar field pass int, int field pass the string will take the index it?
6, linux script wrote it? What does it mean that head? Write a script deposit judgment directory does not exist.
7, the role of the MQ What?
8, ES why should tune Redis, it itself does not store data you can directly check out just fine?
9, to achieve a one-way linked list data structure. Achieve reverse a linked list.
Elephant Vivien
The company basically asked two questions today to say that the interviewer general bar. Feeling is payable. Interviewer waste of time.
1, springboot comments which are not in spring?
2, JVM tuning done it, how to do?
Udesk
one side:
1, how to understand the new JDK1.8 lambda, Stream?
2, there is no lambda way before delivery methods, when accessing external variables with anonymous inner classes, variables must be final, and why?
3. What generics Erase is? JVM be a problem when running behind it? Because they do not know what type of running. List JVM such as how to know what was inside?
4, the thread has what state? When entering the blocking and timeout wait? sleep would be what state?
5, sleep and wait time will throw an exception, what is abnormal? Why throw this exception? Call interrupt () will produce the abnormal it?
6, Which are aware of lock?
7, said that under the structure of the HashMap. What attributes are more important? Load factor affecting the efficiency of how the HashMap? Expansion big factor What happens?
8, ConcurrentHashMap what structure, how to ensure thread-safe? What action will reflect the thread-safe? Why HashMap is thread safe (which reflects the step)?
9, which used design patterns work? Agents and adapters What is the difference?
10, Spring AOP proxy object which is generated when? In the Spring startup process that links the opportunity to bypass the proxy object to access the original object?
11, Spring inside BeanPostProxy know?
12, Spring BeanFactory and the IOC in FactoryBean what's the difference?
13, used ThreadLocal it? If the original thread to start an asynchronous thread, asynchronous thread also need to use the contents of the original thread in ThreadLocal, how do?
14, synchronous blocking and non-blocking synchronization? Asynchronous blocking and asynchronous non-blocking?
15, used what the connection pool? springboot default connection pool?
16, sub-library sub-table how you doing? By month Table how to check historical data?
17, MySQL indexing implementation?
18, how to make SQL queries that do not follow the default indexing? It will be higher than the default MySQL index efficient? (There are null column)
19, the user table id, name, city, found most users of the city?
20, OAuth2.0 the certification process? How to ensure that the process is made token safe? How to ensure that the other party is a legitimate user. How to prevent attacks disguised client?
21, micro-service monitoring how you doing?
Two faces:
1, how to achieve a String own class? String how the stored?
2, ConcurrentHashMap the put operation is what kind of process?
3, CAS ABA problem of how to solve?
4, how to determine whether a string is the format of an IP address? Java provides no method.
5, Redis cluster program to find out about it?
6, data slicing to find out about it? Consistency Hash know? What data structure for consistency Hash? Clockwise find data, how to achieve?
Synway
Police is doing big data, on-site development, small Beijing staff, only five people, and no network development site.
The interviewer is doing the data, do not understand Java, so it made copies pen questions came out, this is purely a waste of time.
Pen questions:
1, the difference between ArrayList and HashSet? HashMap, HashTable, ConcurrentHashMap difference?
2, and the general similarities and differences between abnormal runtime exception?
3, say ArrayList, Vector, LinkedList storage performance and characteristics?
4, the difference between the JSP dynamic and static incloud of incloud?
5, the dependence of the set, scope for the value of any difference in runtime and provided Maven? What is the default value of that?
6, a class need only be designed for the type of access under the same package, which modifier should be used?
7, Tomcat in what is DefaultServlet? What is its function?
8, and a study group by the union all SQL.
9, please say the similarities and differences Template Mode and Strategy Mode.
10, what is the use lock mechanism, briefly pessimistic locking and optimistic locking mechanisms?