Java performance optimization Reading Notes

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 Java program faster and more stable. This book describes the following parts:

Generally, the performance of a program is shown in the following aspects:

Execution speed: whether the program reflects the speed and response time is short enough.

Memory Allocation: whether the memory allocation is reasonable, whether the memory is excessively consumed or leaked.

Start Time: How long does it take for the program to run and process the business properly.

Load Capacity: when the system pressure increases, the system's execution speed and response time increase curve is gentle.

Quantitative Evaluation performance indicators include:

Execution time: the time used to run a piece of code from start to end.

CPU time: the CPU usage time of a function or thread.

Memory Allocation: the memory space occupied by the program during operation.

Disk Throughput: Describes the I/O usage.

Network throughput: Describes the network usage.

Response time: the time when the system responds to a user's behavior or event. The shorter the response time, the better the performance.