Java

First, the system infrastructure:Server: weblogic11g ClusterDatabase: Oracle Database RACError message: 1.java.sql.sqlrecoverableexception:closed Connection2.Test ' Select 1 from DUAL ' Set up for pool ' Mds-soa ' failed with exception: '

Interfaces and internal classes provide us with a more structured approach to separating interfaces from implementations.Abstract classes and interfaces are two mechanisms for defining abstract concepts in the Java language, and it is their presence

String is an immutable class in Java that cannot be modified once instantiated. Once an instance of an immutable class is created, the value of its member variable cannot be modified, and the immutable class has many advantages. Everyone knows why

centos_ Configuration _dockercentos_6.51, centos_6.5 before installing Docker-io need to uninstall the Docker package (not downloaded can be omitted)$ sudo yum-y remove Docker2. centos_6.5 need to first install and enable Epel source before

Object-oriented programming has three main features: encapsulation, inheritance, polymorphism.Encapsulation hides the internal implementation mechanism of the class, which can change the internal structure of the class without affecting the usage,

Import Java.io.bufferedreader;import Java.io.ioexception;import Java.io.inputstreamreader;import Java.io.outputstreamwriter;import Java.io.unsupportedencodingexception;import Java.net.HttpURLConnection;import Java.net.url;import

Java annotations are some of the meta-information that is attached to the code, used by some tools to parse and use at compile and run time, to illustrate and configure functionality.Annotations do not and do not affect the actual logic of the code,

1         Static MethodsBefore we learned some of the ways that static member variables are used, let's look at the content of static methods and see how static methods are used.1.1      methods for defining static methods and general methodsin a

Because the JDK version on the computer and the version of the project group used inconsistent, so need to uninstall, but as a newcomer small white plus no Mac too much experience, or a little bit of some effort, from the Internet to check the

20145311 Wang Yixu "Java Programming" course Summary weekly reading notes link summaryFirst week of Reading notesSecond week reading notesThird week reading notesWeek four reading notesWeek five Reading notesSix weeks of Reading notesSeventh Week

1. JVM Runtime Memory structure1. As constituted. The Runtime Data area has the following areas, where the PC program counter, the virtual machine stack, and the local method stack are thread-exclusive, and the heap and method areas are

First, the article for the reasonStarted the internship, the internship to the Java Development Engineer ...Second, the JVM memory model general diagramIn Java, multiple tasks are processed at the same time through multithreading, and all threads

Pay tribute to the author!Transferred from: http://www.cnblogs.com/peida/archive/2013/04/24/3036689.htmlTo learn more about annotations, we must be able to define our own annotations and use annotations to define our own annotations before we have

Goal:learn about setting and getting the name of the thread. understand the forced operation of threads. understand the sleep of a thread. understand the comity of threads. understand the interrupt operation of the thread. What it does: all of the

The role of threadlocalFrom the previous analysis of threadlocal, it can be concluded thatthreadlocal is not used to solve multi-threaded access problems for shared objects by threadlocal set () The Threadlocal.threadlocalmap method is set to the

Generate verification code, verification code generation String mobile = phone; // mobile number, multiple numbers using "," Split // generate random 6-bit code String s = ""; while (S.length () ) + = (int)

Java concurrent programming Summary 5 -- ThreadPoolExecutor, java concurrent programming practices I. Introduction to ThreadPoolExecutor In jdk1.8, there are four constructors. To ThreadPoolExecutor (int corePoolSize, int maximumPoolSize, long

Maven learning-get started with maven During Java Development, I came into contact with the Maven build tool. So I spent some time learning about this build tool and the Maven knowledge I learned during the learning process. I will share it with you

Final keyword, javafinal keyword The final keyword is a reserved keyword in Java. Once the reference is declared as the final type, the reference cannot be changed. I. Modify Variables The member variables or local variables modified by the final

Java knowledge point summary (irregular updates) and java regular updates1. Generation-based garbage collection Algorithm Design Concept: groups objects based on the length of life into young and old generations. Newly created objects are divided