Java

1. String to ASCII code public static string Stringtoascii (string value) { StringBuffer SBU = new StringBuffer (); char[] chars = Value.tochararray (); for (int i = 0; i 2. ASCII transcoding string public static string

One, the first way to create a thread: Inherit the Thread classclassDemoextendsthread{@Override Public voidrun () {Super. Run (); for(inti=0;i) System.out.println (Thread.CurrentThread ()+"...."+i); }} Public classThreadDemo1 { Public Static

There is a simple Java code as follows Packagecom.dongjak.test;Importjava.io.IOException; Public classTest { Public Static voidMain (string[] args) {//Processutils.shutdown (1);Runtime runtime =Runtime.getruntime (); Try{runtime.exec

analyze the following GC logs:[GC [psyounggen:9216k->1024k (9216K)] 1246196k->1246220k (1287040K), 0.2398360 secs] [times:user=0.29 sys=0.01, real=0.24 secs][Full GC [psyounggen:1024k->0k (9216K)] [paroldgen:1245196k->1245509k (1492992K)] 1246220k->1

There are three concepts that need to be understood first:A Static initialization: Refers to the execution of content inside a static initialization block.Two Instance initialization: Refers to the execution of the contents of an instance

1. Add log4j and slf4j jar packages2. Web. xml:log4jconfiglocation/web-inf/classes/log4j.properties-->classpath: log4j.propertieslog4jrefreshinterval10000 Org.springframework.web.util.log4jconfiglistener3. Src/log4j.properties:# # # set log Levels #

Java's inner class, anonymous class would have thought that their use has been very slip, the result, just yesterday at 12 o'clock, a major accident happened. To say the seriousness of the accident, that is to cause me to sleep all night.Let's use a

Use the session to prevent the form from repeating the submissionIdea: Generate a unique random token on the server side and save the token in the current user's session field. The token is then sent to the client's form form, using a hidden field

Preface: Java's class library is becoming larger, and contains countless classes and interfaces. But there are some very important classes and interfaces that are the core of the Java class Library. Common string, Object, class, Collection,

public static void Main (string[] args) throws ParseException {String strTime1 = "2015-03-01 15:12:25";SimpleDateFormat formatter = new SimpleDateFormat ("Yyyy-mm-dd hh:MM:ss");Date date1 = Formatter.parse (strTime1);String strTime2 = "2015-03-04 15:

Java's performance has some sort of black magic. This is due in part to the complexity of the Java platform and the difficulty of locating problems in many cases. Yet there is a tendency in history for people to study Java performance by

In Java, multiple methods in the same class can have the same name, as long as their argument lists are different, which is called method overloading.Parameter lists are also called parameter signatures, including the type of the parameter, the

Inheritance is the relationship between classes and classes, and is a very simple and intuitive concept, similar to inheritance in the real world (such as a son inheriting a father's property).Inheritance can be understood as a procedure for a class

HBase entry, hbaseI. Basic concepts of HBase 1. Row key The Row primary key can only rely on the Row key when querying HBase. HBase does not support conditional queries and other query methods similar to some mainstream databases. Reading records

10 Best Practices for exception handling in Java Best practices for exception handling in Java programming Here are 10 Best Practices for exception handling in 10 Java programming I have collected. In Java programming, exceptions can be checked,

CountDownLatch thread blocking usage instance, countdownlatch thread There is a common problem in writing multithreading: the main thread (main) starts several subthreads (tasks) to complete concurrent tasks, the main thread will continue to execute

2. Functions of classpath, path, and JAVA_HOME, classpathjava_home Configure JDK environment variables in windows xp: 1. Install JDK. You can customize the installation directory and other information during the installation process. For example,

Java learning-differences between public, private, protected, and other modifiers, privateprotected Public, private, protecte, and default are used to define the access permissions of members in Java, that is, no permission modifier is added before

Java concurrent packet source code learning-AQS framework (2) CLH lock queue and spin lock, aqsclh As mentioned in the previous article, AQS is based onCLH lock queueSo what is CLH lock queue? complexity is complicated, simple, and simple. The

Event transfer 2 (simple press translucent effect) We know that you can add Selector implementation styles to Button or ImageView. For example:     It is red when pressed, and white when not pressed.   Suppose that the picture displayed