Recently developed a demand to obtain the name of the class attribute, but just wants to call it simply and conveniently.

For example, a physical category user contains two properties: ID and username. Now you want to obtain a string of the two attribute names of “ID” and “username”.

Thinking of LOMBOK’s good effect in simplifying the physical class through annotations, so I want to find whether LOMBOK has any annotations to achieve this needs.

After the retrieval of Baidu+Google@FieldNameConstantsMeet demand.

@fieldnameconstants official website introduction

LOMBOK different versions for annotations@FieldNameConstantsThe effect will be different.

The chapterSmall printchapter gives the iteration of the historical version. The LOMBOK version used in this article is 1.18.16

Plagiarism official code DEMO1

import lombok.experimental.FieldNameConstants;
import lombok.AccessLevel;

@FieldNameConstants
public class FieldNameConstantsExample {
    
  private final String iAmAField;
  private final int andSoAmI;
  // Add @FieldnameConstants.exClude This comment indicates that the attribute name does not need to provide attribute name
  @FieldNameConstants.Exclude 
  private final int asAmI;
  
}

Plagiarism of the official DEMO2, the following code is the final Java code effect after LOMBOK uses the annotation. In essence, a internal class is generatedFields。

public class FieldNameConstantsExample {
    
  private final String iAmAField;
  private final int andSoAmI;
  private final int asAmI;
  
  public static final class Fields {
    
    public static final String iAmAField = "iAmAField";
    public static final String andSoAmI = "andSoAmI";
  }
}

Call with junit

package lombok.fieldNameConstatns;


import org.junit.Test;

public class LombokConstantsTest {
    
    @Test
    public void constatnsTest(){
    

        System.out.println(FieldNameConstantsExample.Fields.iAmAField);
        // Output content: IAMAFIELD
        // Since the previous code clip AsaMi field was modified by @fieldnameconstants.exclude, it cannot be called
        // system.out.println (FieldnameConstantSexample.fields.asami); // Can't get the asami attribute! Intersection
    }
}

can see the output stringiAmAFieldis completely consistent with the case of the statement.

1. If you want to use enumeration type: @Fieldnameconstants (asnum = true)
2. If you want to use the output result of the full -write, modify the LOMBOK configuration, the annotation method cannot be configured!

lombok.fieldNameConstants.uppercase = true

3. The default internal class name isFields, and it is

   twenty four# . If you want to modify temporarily, you can use the annotation configuration:public@FieldNameConstants(innerTypeName = "FieldNames", access = AccessLevel.PACKAGE); If you want to modify the internal class name uniformly, you can modify the LOMBOK configuration file

lombok.fieldNameConstants.innerTypeName