Shulou(Shulou.com)06/02 Report--

In this issue, the editor will bring you about how to use the plugin plug-in in mybatis. The article is rich in content and analyzes and narrates it from a professional point of view. I hope you can get something after reading this article.

Mybatis plug-in

Mybatis source code is very well written. Mybatis is a relatively lightweight orm framework, which does not contain too many functions, so it is easy to feel the beauty of its design, so record it by way of blog.

The mybatis plug-in is used everywhere:

Plug-in processing of sql input parameter prameterHandler

Plug-in processing for sql output parameter result

Plug-in stamentHandler

Plug-in executor

Mybatis plug-ins are similar to commonly known interceptors and filters, but the design is not the same, such as:

Springmvc's HandlerInterceptor interface: the interceptor implements a class with a single function and does not participate in the scheduling of the call chain. It is a relatively simple implementation class for a group of interfaces.

Filter:-responsibility chain mode. There is a chain object in the input parameter when each filter is processed. After executing the before in filter, the control is returned to chain, and the next before; is scheduled by chain, and then the chain is called as shown in the figure:

Plug-ins in mybatis implement the Interceptor interface, which is implemented in decorator mode

Give the target that executes the plug-in to the plug-in, and the plug-in returns a proxy object; pass the proxy object to the next plug-in for decoration

Introduce the Plugin object to pass target and plug-in this to Plugin

Wrap the target and wrap the plug-in functionality in the proxy object

Wraps target and proxies target through cglib

The InvocationHandler passed in is the Plugin itself

When the target method is called, enter the invoke method in Plugin

It is only then that the interceptor is called selectively on the target method.

The implementation in the interceptor only needs to pay attention to the processing of the interception logic, because the method call in the target is given to the call in the Invocation object.

Plug-ins designed by mybatis can specify a method of a class to intercept through annotations; this way of design can proxy the target class non-intrusively and proxy multiple times for the same class at the same time; very flexible

The reason for singling out plug-ins in mybatis is that the design is interesting, scalable and different from other interceptors and filters.

This is how to use the plugin plug-in in mybatis shared by the editor. If you happen to have similar doubts, you might as well refer to the above analysis to understand. If you want to know more about it, you are welcome to follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.