java - 什么情况下需要使用多线程编程？

Question

最近在研究多线程，对JMM,Executor框架,ThreadPoolExecutor都有一定的了解了，但是不清楚在什么业务场景下使用多线程编程会有优势？比如就一般的使用SpringMVC+Spring+Mybatis的从Controller到Service再到Dao的流程，哪里能用多线程处理？多线程处理以后就能提高系统的QPS吗？

Answer 1

Java's servlet framework itself is multi-threaded, but this thread is started by the webserver for you, not by the user.

Generally speaking, if you handle network communication yourself, you need to do multi-threading processing yourself, or do background task processing, and you also need to do multi-threading processing yourself.

Main purpose of multithreading:

1. Do not block main thread tasks (background tasks)

2. Concurrency, improve throughput (network multi-threading)