core java interview programs

A transaction (Transaction) is a unit of concurrent control and is a user-defined sequence of operations. These operations are either done or not done, and are an indivisible unit of work. With transactions, SQL Server can bind a logically related set of operations together so that the server maintains the integrity of the data. It is mainly used for some programs which have higher integrity of the operation process. For example, the banking system,

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

-code unit S u+d835 and u+dd6b. (see http://en.wikipedia.org/wiki/UTF-16 for a description of the encoding algorithm.) in Java, the char type describes a code unit in the UTF-16 encoding.Our strong recommendation isn't to use the char type in your programs unless you are actually manipulating UTF-16 cod E units. You is almost always better off treating strings as abstract data types.3.3.4. The Boolean Type

applications can URLs Open and Access objects on the network as if they were accessing local files (here's a myth)1.2.4RobustnessDevote a lot of effort to early problem detection, later dynamic detection, and eliminate the state of error prone, can be detected at compile time some other languages can only be detected at runtime errors.1.2.5 SecurityJava is suitable for network / distributed environments. To achieve this goal, a lot of effort has been devoted to security, and

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

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

. These can be merged and need to be split ." Or something like this. Fortunately, the API documentation is only one page long and can be easily changed. You are more and more confident in the API, and the code will become longer and longer. However, the core principle is to first write the code that uses the API, and then write the code that implements them. Because if the implementation code is discarded, the previous work will be done in vain. In f

the implementation of the interface class to realize the replacement system.Definition of the interface:1. The naming conventions and classes of the interfaces are the same.Example: public interface interface Name {}2. Constants can be defined in the interface, and variables cannot be defined. The properties in the interface are automatically modified with public static final. The constants in the interface must specify the initial values when they are defined.3. The methods involved in the int

Java Basic syntaxSummary of Interview questions (1)1. Can I include more than one class (not an inner class) in a ". Java" source file? What's the limit??? There can be multiple classes, but only one public class, and the class name of public must match the file nameInduced by.2. Is there a goto in Java??? Yes, but it

servletcontext =this.getservletcontext ();(commonly used)The role of ServletContext(1) Get the global initialization parameters of the Web applicationConfiguring initialization parameters in Web. xmlGet parameters from the context object(2) get the absolute path to any resource in the Web AppString path =context.getrealpath (relative to the Web app's relative address);Create a file a.txt under WebContent, create a b.txt under Web-inf, create a c.txt under SRC, and when the relative path is pass

Multicore CPUs are now the mainstream. Using multi-core technology, can effectively play the ability of hardware, improve throughput, for Java programs, can implement concurrent garbage collection. However, the use of multi-core technology in Java also brings some problems,

1 Overview of Object-oriented programmingObject-oriented programs are made up of objects, each containing a specific part of the functionality exposed to the user and a hidden implementation part.Class 1.1A class is a template or blueprint for constructing an object, and the process of constructing an object by a class is called creating an instance of the class.Packaging:Formally, data and behavior are combined in a package, and the user of the objec

This article introduces the objects and classes of Java program Design in depth, mainly involves the following content:-Object-oriented programming-How to create a class object in a standard Java class library-How to write your own class1. OOP overviewObject-oriented programs are made up of objects, each containing a specific part of the functionality exposed to

IntroductionBefore using the online example of some of their own Java technology and the wheel of the fast "rotten" made some small applications, but after all, did not seriously understand and cognitive Java, it is intended to spend about one months time to savor ... Start from the beginning and go deeper!!Definition of JavaJava is not just a language, he is a complete platform , with a huge library of reu

the action within the specified time, the thread stateAutomatically to operational (RUNNABLE).6) TERMINATED (thread end)When the thread executes at the end, it is in state, and this is when the thread's life cycle terminates.There are two cases of thread termination:One is normal end returnThe other is because the exception was previously terminated3. Key code to start a thread in JavaFirst, we have to know that the Runnable interfaceThe Runnable interface has a run () method that is used to st

Concurrent programming is one of the most important skills of Java programmers and one of the most difficult to master. It requires the programmer to the computer at the bottom of the operating principles of a deep understanding, but also requires the programmer logic clear, thoughtful, so as to write efficient, safe, reliable multithreaded concurrent programs. This series begins with the nature of the thre

The core of Java is Object-oriented (fully object-oriented)Object-Oriented ProgrammingYou have to be clear about the three main features of the object1. Behavior of the object2. The state of the object3. Object identificationIn addition, it is necessary to understand the relationship between objects more common relationships haveDependency Inheritance AggregationIn Java