core java questions

Java Collection related interview questions and answers Interview questions1.JavaWhat is a collection frame? What are some of the advantages of a collection framework? There are collections in each programming language, and the original Java version contains several collection classes: Vector, Stack, Hashtable, and array. With the extensive use of the collection

; k ) TestFunction (k, J, i);On the basis of scenario one, this scheme puts the instantiation of the cyclic variables out of the loop, which can further reduce the number of instances of the related cyclic variables, and the scheme time-consuming situation is as follows: Variable Instantiation (number of times) Initialization (number of times) Comparison (number of times) Self-increment (number of times) I 1 1 10 1

Huawei Computer Testing Questions (convert digital string to binary-java), Huawei-java /** Title: convert a numeric string to a binary string Description: enter an integer to convert each integer to a binary number. If the last and third bits are "0", the output value is "0". If it is "1 ", output "1 ". Question category: bitwise operation Difficulty: elementary

Java custom generic interview questions: receive any array to reverse, java custom You can only operate on a certain type for reversal without using the generic type. The Code is as follows: package com.swift.fanxing;import org.junit.Test;public class RenyiReverse { @Test public void test() { int arr[]=new int[] {1,10,6,9,2}; reverse(arr);

1 /*2 3 the value of the base data type is passed without changing the original value, because the stack is played after the call and the local variable disappears4 the value of the reference data type is passed, changing the original value, because even if the method is on the stack, but the heap memory array object is still in, you can continue to access through the address5 6 the value that the base data type passes to the parameter7 the address to which the reference data type is passed to t

MODULE 1Compilation and operation of Java----------------------------Compilation: Javac-d bin Src\helloworld.java-D: Specify the storage path for the compiled class fileIf you call the class of another file in the class of this. java file, you need to compile the called class first, and then enterjavac-d Bin-cp bin Src\helloworld.javaor compile all. java files ja

Java NiO Tutorial (i) Core Overview Java NIO consists of the following core components: Channels buffers Selectors Although there are many other classes and components in Java NIO, it seems to me that Channel,buffer and Selector constitute the

Classes are loaded:　　Refers to reading the binary data of a class file into the runtime data area (the JVM is partitioned in memory)and creates a class object within the method area.Class Loader:Responsible for loading the compiled class file (bytecode file) into the JVM (Java Virtual machine).The class loader is mainly divided into the following types:1.Bootstrap class loader (boot class loader)Responsible for loading the

0000,Which means 128 is 1000 0000 in the computer,The integer.tohexstring parameter is int, and if you do not 0xff, then when a byte is converted to int,Since int is 32 bits, and byte has only 8 bits, this will be the complement.For example, the decimal number of the complement 11111111 is 1 to int when converted to 11111111111111111111111111111111 many 1 ah, hehe!That is 0xFFFFFFFF but this number is wrong, and this complement will cause errors. and 0xFF and after the high 24 bits will be clea

variable that is incremented to uniquely identify a rilrequest. This variable is used as token when it is sent, and tokens seen at the rild layer are the mserail.Event_end:[email protected]@[email protected]2) Send the steps: The first step: Generates a rilrequest that will generate m_serial (the requested token) and fill the request number, data, and result Message object into Rilrequest Step Two: Use Send to package rilrequest to the event_send message to Ril sender Handl

advantage. 1.2.8Explanatory typeThe Java interpreter can execute Java bytecode on any machine that has ported the interpreter . There are still some things that I don't understand for the time being (read the book later)1.3 Java applets and the InternetThe idea is simple: users download java bytecode from the Intern

); - returnJint (HWND); in } - return 0; to } + return 0; -}Johness_jcef3_util_awtutilCompile Build　　　　 Use or test Copy the generated DLL into the Java project, configure LibraryPath in the project configuration, and write the test code.　　　　　　　　The test code is also simple: PackageJohness.jcef3.util;ImportJavax.swing.JFrame; Public classMain { Public Static voidMain (string[] args) {system.loadlibrary

Java Multithreading Core technology comb (with source code) Java Multithreading Core Technology comb the source code written in front Java multithreaded objects and variables concurrent access between threads communication lock usage Timer single case mode and multithreadi

"Java Core technology"Spent half a day and read carefully the Java core technology in the class part, feel the recent programming time a lot of vaguely, "This is not right, try." What's wrong? "The confusion of this sort has been defined earlier. Main function must be in the main class A class is a machine

Java is designed for consumer smart electronics, but smart home appliances are not as big as they were originally imagined. However, in the 90 's, the Internet has entered an explosive stage of development, and overnight, everyone is busy connecting their computers to the network. This time, met a big problem. People find that the Internet is connected to a variety of computers, such as IBM PCs, Macs, various servers and so on, not only the hardware C

type variables? Volatile has two main functions: 1. Avoid command rearrangement 2. Visibility guarantees. For example, the JVM or JIT will reorder the statements for better performance, but the volatile type variable will not be reordered with other statements even if there are no synchronized blocks. Volatile provides happens-before guarantees that a thread's modifications can be visible to other threads. In some cases, volatile can also provide atomicity, such as reading 64-bit data type

Java was originally staged in browsers and client machines. At the time, many people questioned whether it was suitable for server-side development. Now, with the increase in Third-party support for the JAVA2 platform Enterprise version, Java is widely accepted as one of the preferred platforms for developing enterprise server-side solutions. In this article I will explain 13

logic.(2) Pessimistic lock: Still like its name, for the thread security problem caused by concurrency, pessimistic locks believe that competition always occurs, so each time the operation of a resource,Will hold an exclusive lock, just like synchronized, regardless of 3,721, directly on the lock on the operation of resources.25. Collection Class: Hashmap,hashtableHashMap: Thread is not secureHashtable: Thread safety is similar to ConcurrenthashmapVector, Hashtable, Properties and Stack are all

Download address: Network disk download Introduction to the content One of the most influential and valuable works in the Java field, with more than 20 years of experience in teaching and research of senior Java technology experts to write (won the Jolt Award), and "Java Programming ideas," the same as the more than 10-year global best-selling not decline, popul

1365.2 Split iterators with fork/join1455.3 Exception 1495.4 Example Description: Recursive grep1555.5 Summary 166Chapter 6th performance of Flow 1676.1 Micro-Benchmark Metric 1706.1.1 Measuring Dynamic Runtime 1716.1.2 Java microbenchmarking Harness1736.1.3 Test Method 1746.2 Select execution Mode 1786.3 Stream Characteristics 1816.4 Sort 1846.5 stateful operation and stateless operation 1876.6 Packing and Unpacking 1886.7 Split iterator Performance