Farewell to Lombok in 996

Realization principle

Examples of common annotations

  rely on

<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>1.16.18</version>
    // Express jar Packages run at compile time 
    <scope>provided</scope>
</dependency>

Explanation of notes

• @Getter: Generated field get Method
  • @Getter(lazy = true) : Lazy loading , Must use final Decorate the field value
  • @Getter(value = AccessLevel.PRIVATE,onmethod _={@Notnull})
    • value = AccessLevel.PRIVATE: Set the generated get Method's access level
    • onmethod _={@Notnull}: For the generated get Method to add additional annotations
• @Setter annotation : Generate set Method
  • @Setter(value = AccessLevel.PRIVATE,onparam _={@Notnull})
    • onparam _={@Notnull}: Add additional annotations to the parameters
• @ToString annotation
  • @ToString(exclude = {“ Property value ”}) : The attribute value does not generate tostring Method
• @EqualsAndHashCode annotation : Generate for this class equals Methods and hashcode Method
  • The annotation also has some parameters that can be set : For example, exclude some fields
• @Data annotation : Large and comprehensive notes
  • contain :@Getter,@Setter,@ToString,@EqualsAndHashCode
• @NonNull annotation

         

          Generated after adding annotations .class file  

• @AllArgsConstructor,@NoArgsConstructor,@RequiredArgsConstructor
  • @AllArgsConstructor: Generate a parametric construct
  • @NoArgsConstructor: Generate a nonparametric construct
  • @RequiredArgsConstructor

        

•  @Cleanup annotation : Marking on the flow to be closed will automatically close the flow , The effect is equivalent to try-with-source

      

Lombok Advantages and disadvantages

• advantage
  • Automatically generate template code through annotations , Improve development efficiency
  • The code is concise , Focus only on related attributes
  • After adding a new attribute , There is no need to modify the relevant methods
• shortcoming
  • Reduces the readability and integrity of the source code
  • Make troubleshooting more difficult
  • need IDE Support for related plug-ins
• @slf4j annotation ,@Builder annotation ,@singular annotation  

  • @Slf4j annotation : Simplify the log import method to work on classes

  • @Builder annotation : Simplify the process of creating objects

  • @singular annotation : coordination @Builder annotation , Simplify set type operations

  • Log system

           

• @slf4j annotation

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.7.30</version>
</dependency>

// Bridge package 
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-jdk14</artifactId>
    <version>1.7.30</version>
    <scope>test</scope>
</dependency>

• @Builder Notes and @singular annotation  

  • @Builder Completely separate the creation of objects from the use of objects

  • @Builder Add to class : Static attributes cannot be assigned , Initialized final Field cannot be assigned

  • The initialized values of common attribute fields cannot be brought in this way

@Builder
public class BuilderTest{
    // Static attribute 
    private static Stirng staticField;
    //final attribute 
    private final Stirng finalField;
    //final attribute 
    private final Stirng finalField = " Already initialized final attribute ";
    // General attribute 
    private Stirng staticField;
    // Collection class properties 
    @Singular
    private List<String> listFields;

}

// Already initialized final Field cannot be assigned , Static fields cannot be assigned 
// The initialized values of common attribute fields cannot be brought in this way 
// add @Singular after :builder Object time , You can add a field string , You can also add a collection