java practice book

After the use of Zabbix for monitoring, often because of the requirements of the project, the need for Zabbix data, two times to share and develop. How to obtain data from Zabbix is a problem to be solved in this practice. There are two ways to Zabbix data sharing 1 through the database query, get the data. The premise is to have a deep understanding of the Zabbbix database model, and in a large number of monitoring, can not because the query affect t

design. Back to top of pageConclusionThrough a unified definition equals() and you can promote the usability of a hashCode()， class as a keyword in a hash-based collection. There are two ways to define equality and hash values for an object: based on identity, which is the Object default method provided, and based on state, which requires Override equals() and hashCode() . When the state of an object changes, if the hash value of the object changes, you are sure that you are not allowed to cha

[Java project practice] Proxy Pattern, static Proxy VS dynamic Proxy, proxypattern In this blog post, we will compare and learn static proxy and dynamic proxy in the form of class diagrams and code, focusing on analyzing their respective advantages and disadvantages. Definition Proxy Pattern is the structure mode of an object. Proxy Pattern provides a Proxy object for an object and controls the reference

Never thought, "Java Array conversion to list" unexpectedly have so many knowledge, shock and entrainment a little unbearable. About "Java Array conversion to list" is actually very basic knowledge, and there are a lot of people in the blog has been discussed, it is inevitable that I feel that writing such a discussion article how much is not necessary! On second thought, "Do not accumulate silicon step, no

13.3% Design 2h 26.6% Code implementation 4h 53.3% Test 0 0 Analysis Summary 30min 6.7% Experimental Summary (no pairing game programming)The most practical knowledge learned through this experiment is the use of refactoring Raname: How to modify a name. It is an improvement in eclipse, and is now quick and easy to modify, when the name is accidentally misspelled at the time of th

is used when checking user permissions. In short, this part of the content is a bit difficult, you need to be able to write a comprehensive vim command, while the relevant process of Hadoop know.SummarizeNow the Python command, I think, theory and practice is really very different, continuous learning process, not only to overcome the inherent flaws in the code, but also to the kernel principle has a deeper understanding. Fortunately, the good habits

on the Java Practice report, overall is not difficult, for me the biggest difficulty lies in the use of the collection, which also shows my seventh chapter and even the overall use of Java is not good, the seventh chapter because of the lack of proficiency because the code volume does not knock much, many things do not understand, The use of double-row sets and s

MyBusinessException("A message that describes the error.", e); }} Therefore, only when you want to handle the exception to capture, otherwise only need to declare in the method signature let the caller to handle.9. Do not discard the original exception when packing the exceptionCapturing standard exceptions and wrapping them as custom exceptions is a common practice. This allows you to add more specific exception information and be able to

Each Java object has a hashcode () and Equals () method. Many classes ignore (Override) default implementations of these methods to provide deeper semantic comparability between object instances. In the Java Philosophy and Practice section, Java Developer Brian Goetz introduces you to the rules and guidelines you shoul

Java Drp project practice-Environment Building Summary To start a Java project development, we need to build a Java Development Environment. What do we need to build a Java Development Environment, what are the precautions. Process First, let me list the software I us

constructor is set to private, default, or protected level.　　Four Serialization compatibility for different versions of serializable classesAny class that implements the Serializable interface has a static variable that represents the serialized version identifier:Private static final long serialversionuid;The value of the above serialversionuid is generated automatically by the Java Runtime Environment based on the internal details of the class. If

Scala, inheriting a base class is similar to Java, with a two-point limit, and (1) Overriding the method requires the Override keyword, (2) only the primary constructor can pass parameters to the base class constructor. Markerfactory is a single case, once the definition is complete, its name represents the only instance of the singleton object, and the singleton can be passed to the function as if it were a typical passing instance.

Telescopic Content: Synchronized Quick Review The improvement of the synchronized Compare the scalability of Reentrantlock and synchronized Condition variable It's not fair Conclusion Resources About the author The evaluation of the paper Related content: Java Theory and Practice series Synchronization is not the enemy Reducing contention IBM developer Kits for the

,jni_version_1_4)!=JNI_OK){return-1;}Jclass jthiz = Env->findclass (ClassPath);if (Env->registernatives (Jthiz,methods,sizeof (methods)/sizeof (Methods[0])) {return-1;}return jni_version_1_4;}As can be seen from the above code, the JNI layer through the Pthread library to complete the creation of threads, it is important to note that the JNI layer of the thread, must be through the global JAVAVM to get to the environment variables, but also through the global jobject to get the

Java5 adds a new class library concurrency set Java.util.concurrent, which provides rich APIs for concurrent programs that are easier and more flexible in Java 5. This article through a network server model, to practice JAVA5 multithreaded programming, the model used in the JAVA5 thread pool, blocking queues, can be reset locks, but also practice callable, future

In the previous article on the LIBSVM process and the simple Java code test to explain, this article is simple to libsvm how to practice in the project short description, inappropriate places welcome you to correct.The first step is to adjust the predictive function of LIBSVM, and I'm taking some of the code from the Svm_predict class to make predictive defenses, the code is as follows:/*** Classify incomin

Last month, Java technology instructor Sam Pullara showed me his latest Java-enabled phone, Nokia 6630. The phone uses a full range of technologies--embedded JVMs, GPRS, and Bluetooth--but it also suffers from the problems of all smartphones--a limited screen that actually uses the area. Some Web sites support mobile-based browsers, and embedded browsers are trying to effectively render pages on a small scr

cases provides better performance and scalability than locks. If you strictly follow the use of volatile conditions-that is, the variable is really independent of the other variables and its own previous values-in some cases you can use the volatile substitution synchronized to simplify the code. However, volatile the code used is often more error-prone than code that uses locks. The pattern described in this article covers some of the most common use cases that can be used volatile instead syn

application of this pattern is exceeded, it will become very difficult to combine these two competing synchronization mechanisms. Conclusion Compared with the lock, the volatile variable is a very simple but fragile synchronization mechanism that will provide better performance and scalability than the lock in some cases. If you strictly follow the volatile usage conditions-that is, variables are truly independent from other variables and their previous values-in some cases, you can usevolatile

Address: http://blog.csdn.net/kongxx/article/details/7259837 One of Java Socket practices: Single-thread Communication Java Socket practice 2 multi-thread Communication Java Socket 3 transmission object Java Socket practice