java 8 certification questions

. } } 56. Problem: Give an integer variable A, write two pieces of code, the first set of a bit3 is 1, the other bit does not change, how to implement it? /** * @author sanchan * @since 1.0 */ publicclassTest{ publicstaticvoidmain(String[]args){ //给一整型变量a，写两段代码，第一个设置a的bit3 为1，其他bit不变，怎么实现呢？ inta=8; //打印二进制 System.out.println(Integer.toBinaryString(a));//输出 1000 System.out.println(In

statement in try {}, so will the code in finally {} following this try be executed? When will it be executed, before or after return? Will be executed and executed before return. 28. Programming question: How can I calculate 2 by 8 in the most efficient way? Programmers with a C background are particularly fond of asking such questions. 2 29. The two objects have the same value (X. Equals (y) = true), but

the difference between 7.Enumeration and iterator interfaces?The enumeration is twice times faster than iterator, and uses less memory. Enumeration is very basic and meets the needs of the foundation. However, iterator is more secure than enumeration because when a collection is being traversed, it blocks other threads from modifying the collection.Iterators Replace enumeration In the Java collection framework. Iterators allow callers to remove eleme

the difference between 7.Enumeration and iterator interfaces?The enumeration is twice times faster than iterator, and uses less memory. Enumeration is very basic and meets the needs of the foundation. However, iterator is more secure than enumeration because when a collection is being traversed, it blocks other threads from modifying the collection.Iterators Replace enumeration In the Java collection framework. Iterators allow callers to remove eleme

-0=256Byte ..... (byte) 300; 44 300-44=256Equivalent to the data with strong turn-256;Range of Byte: 128 ~ 127128:10 million-128:10000000 (1 Here is the sign bit, also the value bit)3: Default conversion of data type conversionsByte,short,char--INT--long--float--doubleLong:8 bytesFloat:4 bytesA: Their underlying storage structure is different.The range of data represented by B:float is larger than the range of longLong:2^63-1float:3.4*10^38 > 2*10^38

of reflection, how to optimize?Definition of reflection mechanism:is in the running state, for any one class, can know all the properties and methods of this class, any object can be invoked through the reflection mechanism of a class of any method, the dynamic acquisition of class information and the function of dynamic call class object method is called Java reflection mechanism.The effect of reflection:1. Dynamically create an instance of the clas

article to learn more about the callable,future example.6. What is Futuretask?Futuretask is a fundamental implementation of the future, and we can use it with executors to handle asynchronous tasks. Usually we do not need to use the Futuretask class, it becomes very useful when we intend to rewrite some methods of the future interface and keep the original base implementation. We can just inherit from it and rewrite the methods we need. Read the Java

results of multi-threaded running, can cancel the task of the thread if the waiting time is too long without getting the data needed 8. What causes thread blocking blocking refers to pausing the execution of a thread to wait for a condition to occur (such as a resource is ready), and the students who have learned the operating system must already be familiar with it. Java pr

entire system?2. High concurrency, how our system supports a large number of requests3. How the cluster synchronizes session state4. Principle of Load Balancing5. If there is a particularly large amount of traffic to the database, how to do optimization (db design, dbio,sql optimization, Java optimization)6. If there is a large area of concurrency, on the basis of not increasing the server, how to resolve the server response is not timely problems. "

Recently, the developer headlines shared a "Xiaomi Java second Round", a lot of Java programmers expressed great interest.I will share with you the second round of Millet Java (Huawei Java Engineer Written test paper can see the end of the article):0, talk about the understanding of spring1. Inheritance relationships f

BULK INSERT? What data formats are used for both front and back interaction? How does the JSON data format verify the format correctly? Try ... catch ... With return, finally executed before return or after? How garbage processor GC works, when the GC executes Order of execution of SQL keywords Springmvc How to build the environment? Spring Hibernate? What are the notes for spring? SPRINGMVC's annotations,hibernate annotations? Several states of a thread? What is the difference b

take out 1 position: Product: 4 The consumer takes out from 0 position: Product: 2 producer put in 0 position: Product: 5 consumer removed from 0 Position: Product: 5 producer put in 0 position: Product: 6 consumer is removed from 0 position: Product: 6 producer put in 0 Location: Product: 7 producer puts 1 position: products £ º The producers are placed in the location of the product: 8 Position: Product Consumer removed from 1 position: Product: 9

same after adding one, then the tail pointer runner continue to scan backwards. The algorithm ends when the tail pointer runner reaches the end of the string. The complexity of O (n) + O (n) = O (n). instring s = "adbcabed"For example, in meeting the first repetition of aaits maximum non-repeating substring length is4.at thisWalkerin theS[0],runnerin theS[4], the length of this non-repeating substring is4.will thenWalkermove toD, i.e.S[1]. Will beRunnercontinue backwards later. WhenRunnermove

character set toThree. Query statements1. Please use an SQL statement to query the total number of people in each departmentSelect department_name,COUNT(DISTINCT from wcemployGROUP by Department_name2. Use an SQL statement to find out the average salary of the staff in different departments as "fitter"Select department_name,AVG from wcemploywhere type= ' Fitter ' GROUP by department_name//If there is no grouping, an error occurs3. Please use an SQL statement to find out the department of the

). 7. Java communication programming, programming questions (or Q A), using Java socket programming, read the server several characters, and then write the local display? 8. What is the difference between forward () and redirect () in Java Servlet APIs? The forward (

or processed by the program. 7. In Java, a class is declared as the final type. What does it mean? Indicates that the class cannot be inherited. It is a top-level class. 8. Describe your most common programming style. 9. What is the difference between heap and stack. Stack is a linear set. The operations for adding and deleting elements should be completed in the same segment. The stack is processed as fol

overrides and method overloads. Method overrides (overriding) and method overloads (overloading) are different manifestations of Java polymorphism. Overriding overriding is a representation of polymorphism between a parent class and a subclass, and overloading overloading is a representation of polymorphism in a class.If you define a method in a subclass that has the same name and arguments as its parent class, we say that the method is overridden (o

Test your Java basic test questions: This is a few interview questions I designed. The requirement is that there should be as few questions as possible and they can be completed within five minutes, but it can basically reflect the level of knowledge of the interviewer. So I designed six questions.If you are able to fi

iteration.What is the difference between 7.Enumeration and iterator interfaces? The enumeration is twice times faster than iterator, and uses less memory. Enumeration is very basic and meets the needs of the foundation. However, iterator is more secure than enumeration because when a collection is being traversed, it blocks other threads from modifying the collection.Iterators Replace enumeration In the Java collection framework. Iterators allow call

iteration.What is the difference between 7.Enumeration and iterator interfaces? The enumeration is twice times faster than iterator, and uses less memory. Enumeration is very basic and meets the needs of the foundation. However, iterator is more secure than enumeration because when a collection is being traversed, it blocks other threads from modifying the collection.Iterators Replace enumeration In the Java collection framework. Iterators allow call