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As a Java developer, career planning is a very important factor. One year, three years, five years, and ten years are a hurdle. If you keep boiling frogs in warm water , you don’t have to think about it, there will be no good development and Wherever you go, of course, Dachang will also miss you. The reserve of the programmer's technology stack is very important. It cannot only have theoretical knowledge. To combine theory and practice, each section needs a corresponding systematic knowledge system, which cannot be put down.
And in recent years, the competition for positions in Java development has also been fierce . After all, this position does not care about birth. It is the gospel of many people. With their own efforts, they can get a high salary and move on to the road of winning and marrying white and rich. Yes, haha O(∩_∩)O! (Take a skin) But the recent Java interviews for the Golden Nine and Silver Ten and the 2021 Golden Three and Silver Four are very difficult, and they are getting more and more difficult. Many people will have this kind of question. I will not study unless I ask for the interview. I am working. If you don’t need me, you don’t need to know the mentality. The reserve of every knowledge point is reasonable. If you don’t ask, it doesn’t mean you can’t. If you don’t need it, it doesn’t mean you don’t need to learn. If you want to be better than others, you must know what others don’t know. , Be proficient in what others know, and know what others will use. Only in this way, no matter if you raise your salary or change jobs, you will have your place. There may be many people who think that this is big talk, standing and talking does not hurt back. Similarly, if you are an interviewer, would you have to learn SpringBoot to cope with it, or should you be proficient in Spring Family Bucket? The answer is unknown! ! !
Here are some questions that will be encountered in Java interviews: through 200 targeted interview questions, a systematic summary of IT from career planning, Java basic knowledge, advanced Java development technology, interview skills, emotional quotient and IQ Common test sites for companies recruiting Java programmers. Most of the content of this book is based on the real interview questions of major IT companies, which can help readers accurately grasp the characteristics and context of IT company interviews and find their favorite job in the fierce competition.
Java programmer interview book content and knowledge system
Part 1 Preparation for Job Search (Chapter 1)
The main content of this article includes personal mentality positioning, preparation of interview materials, delivery of resumes, interview process, practical interview skills and common questions. This article strives to be simple and easy to understand, so that readers can prepare for the job search from the beginning, understand the entire process of the interview, and build confidence.
Chapter 1 Things You Must Know Before Applying for a Software Development Position
People often say: Opportunities are always reserved for those who are prepared. Before applying for a job, you must be clear about your job-hunting attitude, be familiar with the job-hunting process, be fully prepared, and do some foreseeable things well. In this way, you can be confident and not surprised when you are recruiting. During the job search process, some things are unpredictable. These things may disrupt the mindset of job seekers and affect the results of the job search. If the candidate can do the preparation work as soon as possible, even if something unexpected happens, it will not have much impact, and keep the situation within his control.
- 1.1 Understanding career planning
- 1.2 Application process
- 1.3 Method of interview
- 1.4 Summary
Chapter 2 Java Basic Knowledge (Chapters 2~6)
This article contains 70 interview questions, the main content includes Java program foundation, grammar foundation, object-oriented programming, data type, data collection, graphical user interface development, etc. The content of this article is the foundation of Java language and Java system structure. A large number of example codes and diagrams are used in the explanation to facilitate readers' understanding.
Chapter 2 Java Program Fundamentals
Java is a language as well as a technical specification, which covers various aspects such as desktop applications, enterprise-level programs, and mobile device applications. A deep understanding of the basic concepts of Java is very important for mastering the higher-level technologies of Java.
- 2.1 Development and operating environment
- 2.2 JAVA language overview
- 2.3 Production, deployment and configuration
- 2.4 Summary
Chapter 3 Basics of Java Syntax
The grammar of the Java language is quite similar to C/C++, with a legacy of C/C++. Therefore, it is relatively easy for programmers with CIC++ programming foundation to learn Java. However, there are essential differences behind some grammatical similarities. While understanding Java grammar, readers need to distinguish their principles and implementations from C/C++, so as to have a deeper grasp of Java grammar.
- 3.1 Basic types and syntax
- 3.2 Objects and types
- 3.3 Package and access control
- 3.4 Summary
Chapter 4 Data Types and Type Conversion
Data is the object of program operation and the core of the program. A program that loses data has no meaning. Java data types can be divided into two categories: basic data types and reference data types. Basic data types include: byte. short, int, long, float, double. boolean and char 8 kinds. The reference type is a kind of handle type data of the operation object. However, the objects manipulated by reference types are also based on basic data types. Therefore, the understanding of basic data types is the basis of Java learning.
- 4.1 Integer data
- 4.2 Real data
- 4.3 Boolean data
- 4.4 Character data
- 4.5 String data
- 4.6 Summary
Chapter 5 Use of Arrays and Collections
Regardless of basic types of data, or reference types of data, they can be manipulated in the form of collections. In Java, the most common forms of manipulating data are arrays and collections. The array of Java language is more characteristic, as a special class in Java, it manipulates basic data types and reference data types in different ways. In addition, the Javautil package provides some collection classes, including linked lists, collections, Maps, etc. They are more convenient to manipulate data sets than arrays. They have their own characteristics, and the ways of storing and manipulating data are different. They should be used in different situations. The collection class.
- 5.1 Java values
- 5.2 Collection framework
- 5.3 Summary
Chapter 6 Java Graphical User Interface
The graphical user interface (GUD) is an important aspect of Java development, although its current popularity is not high. However, some companies that have a soft spot for Swing still require developers to have the ability to develop graphical user interface programs. In addition, the graphical user of Java belongs to the category of Java SE, which is a stage in the process of learning Java. Its API is designed to be reasonable and easy to use. By examining the knowledge of the graphical user interface, you can see some of the applicant’s Java development and design skills. .
- 6.1 Basics of Graphical User Interface
- 6.2 Layout control
- 6.3 Event Model
- 6.4String programming application
- 6.5 Summary
Chapter 3 Java Advanced Features (Chapters 7~11)
This article contains 46 interview questions, the main content includes Java 10 system, multi-threaded programming, reflection mechanism, network programming, database access, etc. The content in this article are all advanced technologies that are often used in Java programming, and these technologies are often the focus of Java interviews.
Chapter 7 Input and Output Streams
Input and output are issues that any computer program needs to involve, and Java programs are no exception. Java is developed along with the development of the network, and I/O (input and output) is the basis of network communication. Java's 10 design is very reasonable and it is very convenient to use. There are quite a lot of APIs about I0, it is impossible to remember all of them, and it is impossible to use them all. The key is to understand several core concepts of the API under the javaio package. For example, stream, byte stream, character stream, cache, etc., most of the classes or interfaces are carried out around these concepts.
- 7.1File class
- 7.2Stream class
- 7.3 Serialization
- 7.4 Summary
Chapter 8 Multithreaded Programming
For concurrency, there are generally two ways of multi-process and multi-thread. The process is the basic unit of the system such as CPU and memory occupied, and the thread is the execution unit of the process. Multi-process concurrency is very difficult for data sharing, while multi-threading is quite easy, so most of the time, concurrency refers to multi-threading. Java's multithreading is language-level and does not rely on any operating system APIs, and Java's multithreading programming capabilities are very powerful and easy to use.
- 8.1 Basic concepts of multithreaded programming
- 8.2 Multithreaded Programming in Java
- 8.3 Summary
Chapter 9 Java's reflection mechanism
The reflection mechanism (Reflection) is a relatively advanced function provided by Java. Generally, Java developers use it relatively rarely. However, Java reflection is the basis of most frameworks, such as Struts, Hibernate and Spring. The reflection mechanism is like a surgeon’s antidote tool. Suddenly a person comes from outer space. How do you know its specific structure? The best way is to dissect it. The reflection mechanism is used to dissect Java classes, Interfaces, methods, attributes and other elements.
- 9.1 Reflection basics
- 9.2 Examples of reflection applications
- 9.3 Summary
Chapter 10 Java Network Programming
Since the day Java was born, it has been developed along with the development of the network. Therefore, Java will definitely provide sufficient support for network programming. The basic programming mode of network communication in most computer languages adopts the form of Socket (socket), and Java is the same. This mode is based on the TPCCP communication protocol that is currently popular around the world.
- 10.1 Fundamentals of Network Programming
- 10.2 Java network programming examples
- 10.3 Summary
Chapter 11 Java Operations on Databases
The database is one of the most used server software today. Simply put, its function is data storage and retrieval. If you need to access the database in a Java program, is it supported? This is for sure. The preferred technology for Java and database connection is of course JDBC (Java DataBase onnctivity, Java database connection), which is embedded in the JDK, which can shield the differences between various databases and use the unified relational query statement SQL for data Add, delete, check and modify operations.
- 11.1 SQL basics
- 11.2JDBC
- 11.3 JDBC various operation data sources
- 11.4 Summary
Chapter 4 Java EE Related Questions (Chapters 12~14)
This article contains 43 interview questions, the main content includes Web development foundation, SSH framework (Struts, Spring.Hibermate), EJB and JPA, etc. The content in this article is the content that must be mastered in Java Web development, and it is also another focus of the interview for Java programmers.
Chapter 12 Web Development Related Technologies
Java Web development is currently the most widely used field of Java, and there are often the most interview questions about Web development. Sometimes, the Java development that people often talk about refers specifically to Java Web development. In Web development, there are many and mature technologies, and it is not easy for developers to master comprehensively and thoroughly. For more core knowledge, including Servlet, JSP, MVC, etc., it is the focus of the interview.
- 12.1 Servlet and Web Container
- 12.2JSP dynamic language
- 12.3 Expression language and JSTL
- 12.4 Summary
Chapter 13 Combination of Struts, Spring and Hibernate
In the field of Java Web development, three frameworks are very famous: Struts, Spring and Hibermate, referred to as SSH for short. They perform their respective duties in Web applications, and perfectly structure Web applications, which can not only improve development efficiency, but also facilitate daily maintenance. Struts is a typical MVC model framework, which is mainly responsible for receiving and responding to HTTP requests.
- 13.1MVC and Struts
- 13.2Hibernate
- 13.3Spring
- 13.4 Summary
Chapter 14 EJB and JPA related issues
When J2EE develops to the fifth version, which is Java EE 5.0, the adjustment of EJB is significant, and the new version of EJB is called EJB 3.0. It is no longer difficult to develop EJB programs. It uses Java 5.0 standard annotations (Annotation) to replace EJB's complicated XML annotations, and removes some unnecessary interface intrusions, so that EJB beans can be ordinary Java classes, which are supported by many developers .
- 14.1EJB3.0
- 14.2 JPA specification
- 14.3 Summary
Chapter 5 Algorithms and Design Patterns (Chapter 15)
This article contains 15 interview questions, the main content is the knowledge of algorithms and design patterns that Java programmers often encounter during interviews. Algorithms are the soul of programs; design patterns are a summary of some classic development patterns by predecessors, which can solve some common problems. Algorithms and design patterns are often the focus of technical interviews.
Chapter 15 Java Programming Test Questions
Algorithms are the soul of any program. Some developers think that Java provides a rich API, which can already accomplish most of the functions relatively easily. Therefore, programmers can ignore the algorithm, as long as they are familiar with the usage of the API. This is a wrong idea. In fact, in most cases, the execution efficiency of Java programs still depends on the developer's algorithm. Especially for fresh graduates, the recruiting unit often does not examine the things that fresh graduates practice too much, but requires them to have an agile algorithm mind.
- 15.1 Basic Programming Test Questions
- 15.2 Advanced Programming Test Questions
- 15.3 Summary
Chapter 6 EQ and IQ Classic Interview Questions (Chapters 16, 17)
This article contains 26 interview questions, the main content is EQ and IQ interview questions. EQ and IQ tests can not only examine the comprehensive resilience and logical ability of job applicants, but also examine their breadth of knowledge, learning ability, judgment, and problem-solving ability. In addition, you can also learn about the personality characteristics of job applicants through these questions. Therefore, this type of question is also a hot issue in programmer interviews. The answers to these questions are not necessarily unique. This article focuses on analyzing the reasoning process and answering ideas of these questions, and the actual interview should be answered according to the specific situation.
Chapter 16 EQ Interview Questions
Although software development is a technical job, in the interview process, some emotional intelligence interview questions are indispensable. These interview questions are not intended to examine the technical level of the job seeker, but through these questions to see the job seeker’s mentality and ability to analyze and solve problems. This chapter will cover some common emotional intelligence interview questions in IT interviews, and analyze these questions to help readers answer these questions appropriately according to their own situation.
- 16.1 Graduation Issues for Freshmen
- 16.2 Answers to regular questions
- 16.3 Summary
Chapter 17 IQ Interview Questions
In the interview questions of some large companies, you can often see some IQ interview questions, which can examine various information such as the job seeker’s logical thinking ability and brain reaction speed. In this era, no matter what type of job interview, there are generally more or less such questions. They are also common interview questions in IT interviews in the past two years. Their answers may not be uniform, but there is one A certain idea is mainly determined by factors such as the job seeker’s life experience and wisdom.
- 17.1 Brain teasers
- 17.2 Logical Reasoning
- 17.3 Computational Reasoning
- 17.4 Summary
Of course, only interview questions are not enough. If you want to learn better, you still need to have a systematic learning goal, so that you can learn and improve better. The following summarizes multithreading, JVM, message middleware, RPC, SpringBoot, SpringCloud, Docker, MySQL, Git, Mybatis, source code analysis, Xmind of landing projects to combine learning:
Last wordy
Java interviews are indispensable whether you are looking for a job or changing a job to raise your salary. You must be proficient in what you know, and you must be familiar with the application. In the world of programmers, "knowing" is equivalent to not being able to. There is no answer; every effort will be rewarded, and every effort is worth seeing.
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