java performance tuning and optimization

usually does not reclaim the memory occupied by static variable objects, so use static area code reasonably.3. Use basic data types instead of objectsIn Java, a string object consists mainly of 3 parts:The length of the char array, offset, and string.String str = "Hello"; A "Hello" string is created, and the character cache pool of the JVM also caches the string; string str = new string ("Hello")//The string object referenced by Str also contains a c

Save it first. Try to use it when necessary. Java performance optimization is a common problem. This problem is not only encountered during interviews, but also in actual work. We will not discuss the specific details here, this section only describes the Java tool used to check the program's

Program | performance | Optimization 1 using non-blocking I/O The less-than-version JDK does not support non-blocking I/O APIs. To avoid I/O blocking, some applications use a method of creating a large number of threads (in better cases, a buffer pool is used). This technique can be seen in a number of applications that must support concurrent I/O flows, such as Web servers, quotes, and auction applicatio

, connection pooling (C3P0, DBCP)11, Database data classification storageStore frequently accessed data and low-frequency data, respectively, into different partitions, or even to different database servers, in order to fit into the allocation of hard disk I/O and system I/O.12. Cache PolicyIf some data is to be read from the database frequently, and the data does not change frequently, the data can be cached in the system and read the cache directly, instead of frequently accessing the database

I have been studying Java for more than five years.CodeThe frameworks used to complete functions as needed are popular and seldom consider their performance. Currently, some large projects have built a framework with many functions, and the access speed is always low, now I am thinking about how to optimize performance.ProgramPerformance Optimization-Make your

static variables, GC usually does not reclaim the heap memory of this object14. Declare a constant as static final and name it in uppercase15, string variable and string constant equals when the string constant is written in front, the variable is written in front, and Null is written in the back.16. To convert a basic data type to a string, the base data type. ToString () is the quickest way, string.valueof (data), Data + "" slowest17. The collection must specify the template type (5.0+). Desc

maintenance because programmers can quickly understand these modules and can debug them without harming other modules. Although the encapsulation itself, both internal and external, will not bring better performance, but it makes effective performance tuning possible. Once a system has been completed and analyzed to see which modules affect the

Proxy mode for Java program performance optimizationThe proxy mode is widely used, for system security and for remote calls. Here we mainly discuss the delay Loading Caused by program performance optimization. First, let's take a look at the proxy pattern design. First, let's briefly describe what proxy pattern is. The

is faster than using global variables. You can see the non-denaturing String class source code will know(8) about Locks Java There are read and write locks and the ability to try to acquire a lock, you can see Readwritelock class(9) A memory leak occurs, and the analysis discovers the global GC (gabage Collection) frequently, you may consider checking your code for large List , Map , arrays, and so on, using the corresponding Clean method to mitigat

In Java programs, apart from the Core algorithms, the major cause of performance problems is the code of the program itself. Therefore, optimization of program details can greatly improve the performance of the program. 1,Make the final modifier of the class as much as possible, because the final modifier class cannot

knowledge, and then Baidu a bit using the Jstack command to print out the stack information analysis is that part of the code problem. However, the stack of information is printed out, but it is completely not understood (hope to have a big God pointing out). There is no way to finally have a piece of code, a piece of code measured (feel there should be a better way). Although the method is a bit stupid, but finally did not expect to find the murderer, the original is the reflection part of the

used to control the process.4. Use local variables as much as possibleLocal variables, the parameters passed when the method is called, and the creation of temporary variables are saved in the stack (stack), faster, other variables into static variables, global variables are created in the heap (heap), slower.Extension: The stack is allocated by the system, faster, the stack uses a first-level cache, they are usually transferred to the storage space, the call is immediately released, the heap i

) output:if (logger.isdebugenabled ()) { logger.debug ("Entry number:" + i + "is" + string.valueof (Entry[i]));} In addition to the log level and log messages, usually in the log also contains some other information, such as date, thread name, class information, MDC variables and so on, according to TAKIPI test, if you add class in the log, performance will drop sharply, compared to the default configuration of Logback, the throughput of the declin

A few days ago, a friend found me and said a SQL performance problem to see if it could be optimized, the following is the process:Snow Leopard 9:35:10Are you thereOrchid Island Main 15:07:39Busy forgetting, what's up?Snow Leopard 15:07:49WellSnow Leopard 15:07:54Database optimization IssuesOrchid Island Main 15:08:04Oh, you said.Snow Leopard 15:09:09Select Distincta.suite_no,b.bd_nm,b.crt_date from (select

preliminary optimization (Part 1)-identifying performance bottlenecks Build a high-performance ASP. Net Site Chapter 6-performance bottleneck diagnosis and preliminary optimization (next article)-simple Optimization Measures

Performance TuningIt is undoubtedly a huge topic and a very important part of many projects. Performance Tuning is well known. After all, performance tuning covers too many aspects.ArticleLet's take a look at the process of performance