Java

An exception occurred in the crawler's operation,Java.net.SocketException:No buffer space available (maximum connections reached?): Jvm_bin The httpclient is used in reptiles, and the thread pool is used. Search the next found that other people have

After the system service is turned on, you cannot view the connection success via Web page or eclipse, and connect to the Times error: Java.net.NoRouteToHostException:No Route to host The findings of the Internet search are as follows: There are

Problem The split method of String class in Java, when using "|" When the segmentation is done, the results are not achieved. For example: Split string "abc| DEF ", get the string{} result is“ABC|DEF" Solve Split has two parameters, one is "limit",

The superclass "Javax.servlet.http.HttpServlet" is not found on the Java build Path A "Red" error message appears at the top of the JSP page: the superclass "Javax.servlet.http.HttpServlet" is not found on the Java build Path. The original Javaweb

MD5 algorithm is widely used in digital signature technology Digital signature technology: can detect the integrity of files or other applications, judge whether there is modification; The simple application is as follows:Assume that the end of the

Reproduced from: http://blog.csdn.net/lovelion/article/details/17970147 In 2009, Sean Chambers published an article in his blog about the refactoring:useful Refactoring techniques have to know series, which is published every day to introduce a A

This article address: http://blog.csdn.net/kongxx/article/details/7288896 Java socket Combat one single-threaded communication Java Socket combat two multi-thread communication Java socket Three-combat Transfer object Java socket in combat four

Pre-order Today to face a few companies, mainly Java backend, there is a company to ask the thing is really quite a lot of, here to record a deep impression of the problem it. Java Basics int, Byte, and char each occupy several bits.Note that this

The basic flow of the domestic e-commerce system is as follows: Customer orders-> system within the system according to the order generated Alipay interface URL-> customer through the URL to use Alipay (Online banking) payment-> Alipay will customer

the strategy model of Java and Schema (reprinted from http://www.cnblogs.com/java-my-life/archive/2012/05/10/2491891.html) In Dr Shanhong's "Java and Schema" book, this describes the policy (strategy) pattern: 　　the policy pattern belongs to the

Note: Because I am not accustomed to annotation way, so after the annotation here to achieve the basic configuration, after the annotation will not be taken out alone to explain. V: Spring Annotation 1. Preparatory work(1) Import Common-annotations.

Axis2 is a third-party Web services engine provided by Apache, Axis2 more efficient, modular, and more XML-oriented than its predecessor, Apache axis.  After careful design, AXIS2 provides more convenient module add function. The new architecture is

The input and output capabilities of the Java language are very powerful and flexible, and the drawback is that the code that looks like input and output is not very concise, because you often need to wrap many different objects. In the Java class

Velocity is a java-based template engine (the role of the template engine is to get the data and process it, and finally display the data).It allows anyone to simply use the template language to refer to objects defined by Java code.Mainly used

HashMap, Hashtable difference.1, HashMap thread is unsafe, hashtable thread safety;2, HashMap the keys and values are allowed to exist null values, and Hashtable not allowed;3, HashMap efficiency is higher than Hashtable* Hash table based

Today learned a bit of spring boot in the MyBatis, with MyBatis to add and remove users, access to users, adding users, modify users, delete users, modify the user, are all right, but get a list of users with pagination, Always throw this

1. Crawler classification: Distributed and standaloneDistributed is mainly Apache Nutch framework, Java implementation, rely on the operation of Hadoop, learning difficult, generally used only to do search engine development.Java stand-alone

4.1 Basic Concepts 4.1.1  Java language a bit 4.1.2      Java interpreted language      C + + compiled language 4.1.3 The main method can be the same name but the type cannot be repeated 4.1.5 static initialization order: The parent class static

Java Multithreading-----------------volatile memory semantics　　The volatile keyword is the most lightweight synchronization mechanism provided by a Java virtual machine. Because the volatile keyword is related to the Java memory model, we have added

The purpose of defining the specification is to unify the code style of the project so that the program is readable.Name of package (all lowercase, defined by domain name)The Java package name is made up of lowercase words. However, due to the Java