Java

1. What are the common commands of Linux?1. Find the file Find/-name filename.txt based on the name lookup/directory filename.txt file. 2. See if a program is running Ps–ef|grep Tomcat view all processes related to Tomcat3. Terminating thread kill-9

First, enter rootAs you can see, I'm using the CentOS 6.5 system.Second, test network and Yum is available1. Test the network ping www.baidu.com, if it isReference:One, JDK installation1, Linux under the Yum Direct installation: 511831152,

First, take a picture:For a class, the access control has only one public and no default modifier. Several other access modifiers are available for both variables and methods.The following describes the specific use.1. Public access Control

1. ArchitectureHiro is a powerful, easy-to-use Java security framework that is used primarily for more convenient authentication, authorization, encryption, and session management. Shiro's primary and most important goals are easy to use and easy to

Protected modified static properties and methods call Way 1: Direct class name invocation2: Instantiation of the parent class object for invocation3: Instantiating a subclass object for invocationProtected modified non-static properties and Methods

1. Constructors Because an object constructor that creates a class is automatically executed, it is very good to initialize something 2. Method overloading Method names are the same, parameter lists are different. 2.1

JSON serialization Common tool Class (Java)> to support the normal use of this tool class, first import the following jar packagesThe 1.lombok package is a jar package that simplifies Java redundancy code and is very handy in real-world

Jodd is aJava Toolkit and micro-framework,the Jodd tool contains some useful tool classes and small frameworks that enhance the JDK to provide a lot of powerful features that can help implement daily development tasks and make the code more reliable,

title : Jumping GamesDifficulty : Mediumtopic content :Given an array of non-negative integers, you is initially positioned at the first index of the array.Each element of the array represents your maximum jump length is at that position.Determine

Anomaly detection anomaly and non-detection anomaly , the application scenario can be summarized as follows: The calling code cannot continue execution and needs to be terminated immediately. There are too many possibilities for this, such

NetWeaver using transaction code SM59 to create destination:JavaCreate a new destination:Test code:try {Context ctx = new InitialContext (); Connectivityconfiguration configuration = (connectivityconfiguration) ctx.lookup ("java:comp/env/

OverviewI/O streams are divided into two major categories: character stream and byte stream.Byte stream (Basic stream)1, byte input stream class name: FileInputStream feature: Read (read to file) Parent class:InputStream2, byte output stream class

[Java Exceptions]The base class for all exceptions and errors in 1.java is throwable** throwable** error exception* (check-in exception) (Runtime exception) * * Exceptions in 2.java are divided into runtime exceptions and check-in exceptions. *

I. Designing Thread-safe classes Find all variables that construct the state of the object (if the variable is a reference type, also includes a field in the Reference object) Invariant conditions of constrained state variables

Demand ScenariosDeveloping a Web Office system if you need to work with a large number of Word documents (such as thousands of documents), users must ask for a document that contains some keywords, which requires the ability to read text in Word,

We used classes to create new types (type) and use inheritance to facilitate the process of creating classes. I will delve into the type in this talk and introduce the concept of polymorphism (polymorphism).Any of the variables and references in

There are two ways to implement multithreading in Java, one is to inherit the thread class, one to implement the Runnable interface, and the thread class to be defined in the Java.lang package. A class that inherits the thread class to overwrite the

Setscale (int newscale,roundingmode Roundingmode)BigDecimal The non-scaling value of the BigDecimal is determined by multiplying or dividing the appropriate power of 10 to maintain its value.If the operation reduces the scale, the non-scale value

1. Inherit thread, rewrite run ()public class MyThread extends thread{ @Override public void Run () { System.out.println ("Run Procedure" ); }}2. Implement Runnable, re-run ()public class Myrunnable implements Runnable {

First: Comparable sort interface If a class implements the comparable interface, it means "this class supports sorting." Assuming "There is a list (or array) of elements that are classes that implement the comparable interface, the list (or array)