Java

First, why to use DbutilsUse Dbutils to greatly simplify code writing, making development progress faster and more efficientSecond, dbutilshttp://commons.apache.org/proper/commons-dbutils/download_dbutils.cgi The DS that appears is a data

collection typeSet collection: The collection element cannot be duplicated . Elements are not in order . So it cannot access elements based on location. TreeSet and HashSet are its implementation classes.List collection: The collection elements can

Java Learning Note (2015.7.27~7.31) Java Learning Note (2015.7.27~7.31)Java课堂 Java Learning Note (2015.7.27~7.31) Little Tricks Common methods 1, list another sub-class--linkedlist 2. Common methods of

Introduction to the Singleton patternThe singleton mode (Singleton), as its name implies, is an object-creation pattern that guarantees that a class has only one instance and provides a global access point to access it . To do this, we need to make

Transferred from: http://blog.csdn.net/yaerfeng/article/details/7103397Today the project encountered a problem, to invoke a class, and get the properties of the class to be assigned and then pass the class to the method as a parameter.The actual

In C + +, allocating objects on the heap is more expensive than allocating objects on the stack. The program needs to find the appropriate memory block and return the memory address. In Java, however, the garbage collector significantly increases

Memory management has always been a need to be considered carefully in the past when I was engaged in C + + development. In C, we use the library function malloc () and free () Two library functions to allocate memory and release from the heap,

Java log output control at the method level (i) This article mainly discusses the log output through the properties configuration file and the AOP Technology batch control method level.The advantage of using the properties profile is that you can

In the previous blog, we described how to create the first EJB project using Eclipse+jboss, and encountered an error during this period:Exception in thread "main" java.lang.ClassCastException:com.sun.proxy. $Proxy 2 cannot is cast to

Public static string decodeunicode (string thestring)  {    char  achar;    int len = thestring.length ();     Stringbuffer outbuffer = new stringbuffer (len);    for  (int  x = 0; x Convert Java Unicode to Chinese

1.JAR Package IntroductionTo enable the program to run, the Json-lib package must be introduced, and the Json-lib package relies on the following jar packages: Commons-lang.jar Commons-beanutils.jar Commons-collections.jar

054-spiral matrix (spiral matrix)"leetcode-Interview algorithm classic-java Implementation" "All topics Directory Index"Original QuestionGiven a matrix of M x n elements (m rows, n columns), return all elements of the matrix in spiral order.For

Use of generics in Java collectionsGenerics provide a lightweight and flexible data operation, and the security of the data is relatively improved.Generics provide constraints on list elements, such as ArrayList ordered linked lists, which can store

1:final Keywords (master)(1) is the final meaning, can be modified class, method, variable. (2) Features:A: It modifies the class and cannot be inherited. B: It modifies the method and cannot be rewritten. C: The variable it modifies is a constant. (

If tomcat is deployed in docker and java applications are deployed 1. Deploy tomcat in docker Step 1: log on to the root directory of the system and create the tomcat7 folder. Run the command mkdir tomcat7 and switch to the directory cd

Java reflection mechanism principle and java reflection mechanism Principle Concepts of a reflection mechanism: All attributes and methods of a class can be known for any class in the running state, and any method of the class can be called for any

The old ape will also make mistakes and make mistakes. Recently, many low-level errors have been found in the Process of continuously testing and completing functions under a project. These problems are basically discovered through breakpoint

A jvm parameter with better performance Jvm parameter configuration for a good web server: -Server // server mode-Xmx2g // The maximum heap memory that can be allocated by JVM, which can be allocated on demand.-Xms2g // The initial heap memory

CAS implementation in spring MVCConcept:   SSO: Single Sign On Single Sign-On. SSO is one of multiple application systems. Users only need to log on once to access all mutually trusted application systems.  Principle:     This is the system

Add a GetInputStream Extension Method to string. Sometimes, we need to read some data, regardless of whether the data is from the data file on the disk or from the network. Therefore, the following StringExtensions. cs is available:  1 using