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This article mainly explains "what are the advantages and disadvantages of Spring annotation configuration and xml configuration". The content in the article is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought to study and learn what are the advantages and disadvantages of Spring annotation configuration and xml configuration.

Advantages of Xml

1:xml is centralized metadata and does not need to be bound to code

In our development, the xml configuration file is distinguished from the code class. There is no need to bind to the code

2: using xml configuration can make the software more scalable.

For example, in spring, we don't want to use the interface but the implementation class of the interface, so we only need to change the class value of bean in the xml configuration.

3: the relationship between objects is clear at a glance

For example, we are reading configuration information based on xml configuration, as shown in the following figure:

Editing

From the xml structure, we can see that there is a property of locations in the popertyPlaceholderConfigure class, and it is a list collection.

For example, using xml to configure a data source is:

Editing

The properties of the DataSource object are clear at a glance.

4:xml definition: extensible markup language, a subset of the standard generic markup language, referred to as XML. From this definition, we can find that the greatest advantage of xml is that developers (programmers) can tailor the tags for the software, making xml easier to understand.

5: mature verification mechanism to ensure correctness. You can use Schema or DTD to verify the correctness of xml.

6: based on xml configuration, only need to modify the xml, do not need to modify the existing program.

7: it is easy to interact with other systems. Data sharing is convenient

Shortcomings of Xml

Although there are many advantages listed above, xml also has its disadvantages

1: if xml configuration is used in an application, tools for parsing xml or support for third-party class libraries are required

2: parsing xml is bound to take up resources, which is bound to affect the performance of the application

Take java as an example, whether it is an one-time xml device into memory, or a line-by-line read and parse, it will take up resources.

Too many 3:xml configuration files can make maintenance difficult

4: the correctness of its configuration items cannot be verified during compilation and can only be found at run time.

5: after making a mistake, troubleshooting becomes difficult. Often in the configuration, a hand mistake will make an inexplicable mistake (although there is always a demon, but it is difficult to troubleshoot)

For example, when xml configures bean information, it is troublesome to check if the value of class has a space. It's a lot of work to investigate.

6: during development, it is necessary to maintain both code and configuration files, which reduces the efficiency of development.

7: there are sometimes many hidden rules between code and configuration items. If it changes either side, it may affect the use of the other party. This is a big pit.

For example: custom tags, if other developers are not clear about these, modify either the code or the configuration of xml, will cause the program not to run properly.

8: development tools do not support xml validation very well.

For example, idea, for xml correctness, if it is custom, the verification is not very good.

After talking about the pros and cons of xml, let's look at the pros and cons of annotations.

Annotation advantages

1: the parsing of annotations can be independent of third-party libraries and can use the reflection that comes with Java.

2: annotations and code together, between classes, reducing the cost of maintaining two places

3: if there is a problem with the annotation, the correctness can be verified during compilation, and it is easier to find if there is an error.

4: the use of annotation development can improve development efficiency. There is no need for maintenance in multiple places, and there is no need to consider whether there are "hidden rules"

Comments shortcomings:

1: it is more troublesome to modify it. If you need to modify the annotations, you need to recompile the entire project

2: handle the complex relationships between business classes, otherwise xml is as easy to modify and not as clear as xml

3: if there are too many annotations in the program, the code quality will be affected, and the simplicity of the code will be affected.

4: if later people do not understand the notes, it will bring cost to maintenance

5: the annotation function is not as fully configured as xml.

A brief summary of the advantages and disadvantages of the two.

Notes:

Advantages:

Simplify configuration

Intuitive and easy to use to improve the efficiency of development

Type safe, easy to detect problems

Disadvantages:

It is more troublesome to modify than xml.

If you don't understand the project, it may bring trouble to the development and maintenance.

Xml:

Advantages:

Uncoupling between classes; easy to modify; easy to expand

Easy to exchange data with other systems

The relationship between objects is clear at a glance

Disadvantages:

Lengthy configuration, requiring additional maintenance; affecting development efficiency

The type is not safe, it cannot be checked, and the error is not easy to troubleshoot.

Simple summary of the note: it is simple and convenient to write, and it looks simple, but it is troublesome to modify.

Summary of Xml configuration: flexible to write and easy to modify, but troublesome to write and maintain

Do you have a better understanding? Welcome to share.

Thank you for your reading, the above is the content of "what are the advantages and disadvantages of Spring annotation configuration and xml configuration". After the study of this article, I believe you have a deeper understanding of the advantages and disadvantages of Spring annotation configuration and xml configuration. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

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