Java

1. What is JDBCJDBC is a public interface that is independent of the specific database management system, universal SQL database access and operation, interface-oriented programming, provides a unified way to access different databases, shielding

1. Can be re-entered lockSynchronized and lock are reentrant locksIndicates that the lock allocation mechanism is thread-based, not method-basedFor example, when another synchronization method is called in one of the synchronization methods, and

1. Inputstream/outputstreamProcessing byte streamsAbstract class: All input, output (memory) class superclass, general use Fileinputstream/fileoutputstreamOutput character UTF8 encoding: if 44312. Inputstreamreader/outputstreamwriterWorking with

The code is as follows:Package Test;import Java.io.*;import Java.nio.charset.charset;import java.util.properties;import Com.jcraft.jsch.channelexec;import Com.jcraft.jsch.jsch;import Com.jcraft.jsch.jschexception;import

I. Classes and Object objectsObject-An entity used to describe an objective thing, consisting of a set of attributes and methods;Attribute--The object has a variety of your characteristics, such as the cashier's age, height, weight;Method-The

Java.lang.Thread.Statemember Inner classNEW: Not yet startedThread state for a thread which have not yet started.RUNNABLE: Running in the JVM, but may be waiting for additional resources from the operating systemThread state for a runnable thread.A

Process: TaskTask concurrency execution is a macro concept, which is a micro-serial.Process scheduling is OS-owned (some systems are exclusive, some systems are shared, and processes are prioritized according to importance).The time is divided by

The Bimap of GuavaThe role of Bimap is clear: it is a one by one mapping, which can be used to get the value of a key, or by value. I. Overview1, Bimap and ordinary HashMap difference(1) In the Java Collection Class library map, it is characterized

I. Introduction of LinkedListSince LinkedList is a dual-ended queue that implements Deque, LinkedList can be used as a queue and as a stack, using pop (), push (), Peek () when LinkedList as a stack. The way to note is that the LinkedList is the

　　Here is a summary of the three auxiliary classes mentioned above:1) Countdownlatch and Cyclicbarrier are capable of waiting between threads, except that they focus differently:Countdownlatch is typically used when a thread a waits for several

This article is to undertake the previous article: Java Multithreading Knowledge Summary (a)Four. Java multi-threading blocking state and line programmingThe specific type of thread blocking is already mentioned above. Here are the main ways to

List InterfaceWe have mastered the use of the collection interface, and then look at the sub-class in the collection interface, they all have those features?Next, we'll learn about several commonly used subclasses in collection (list collection ,set

The thread pool in JavaThe benefits of a thread pool1. Reduce resource consumption. Reduce the consumption caused by thread creation and destruction by reusing the threads that have been created.2. Improve response speed. When a task arrives, the

This happens if you use the Submit (Runnable Task), and any error messages will not appear!This is because when using the Submit (Runnable Task), the wrong stack information will be captured internally when it runs out, so we can not print out the

1. The difference between a streaming socket and a datagram socket and an original socketStreaming sockets: Connection-oriented, reliable data connection, data error-free, no duplication, exactly in the order of delivery. (TCP protocol)Datagram

The Java NiO bufferJava's traditional I/O model is oriented towards a single byte, which abstracts the input output into a stream of bytes or characters. This single-byte read or write model is less efficient and does not conform to the I/O

http://blog.csdn.net/sunxianghuang/article/details/51982979 generic design is designed to reduce manual type conversion Work = = Why is a generic type required? How is the generic program designed without generics? The purpose of generics is to

Ensure thread-safe evolution:SynchronizedVolatileAtomicintegerThe lock interface provides the method:void Lock (): Plus lockvoid unlock (): Unlockingvoid lockinterruptibly (): When a number of threads concurrently acquire the lock, then, when some

Java does not support multiple inheritance, that is, a subclass can have only one parent class, single inheritance makes Java simple, easy to manage, but if you want to overcome the disadvantage of single inheritance to use interface technology, is

multiple inheritance refers to a subclass that can inherit from more than one parent class at the same time, and thus have characteristics of more than one parent class, but the disadvantage is significant .1. If the subclass inherits the same