avaje-record-builder

Uses Annotation processing to generate builders for records.

Distinguishing features

• By default, Collection/Optional Types will not be null (an empty collection/optional will be provided)
• We can choose the default value of a record component in the generated builder
• Support for generating Checker/NullAway compliant builders for static null analysis.

Usage

1. Add dependency:

<dependency>
  <groupId>io.avaje</groupId>
  <artifactId>avaje-record-builder</artifactId>
  <version>${record.version}</version>
  <optional>true</optional>
  <scope>provided</scope>
</dependency>

Add the annotation module as a static dependency when working with Java modules.

module my.module {
  requires static io.avaje.recordbuilder;
}

2. Add @RecordBuilder

@RecordBuilder
public record ArmoredCore(
    @DefaultValue("\"Steel Haze\"") String coreName,
    String model,
    int energyReserve, 
    int ap) {}

The following builder class will be generated for the above:

Generated Class, (click to expand)

/**  Builder class for {@link ArmoredCore} */
public class ArmoredCoreBuilder {
  private String coreName = "Steel Haze";
  private String model;
  private int energyReserve;
  private int ap;
private ArmoredCoreBuilder() {
}
private ArmoredCoreBuilder(String coreName, String model, int energyReserve, int ap) {
this.coreName = coreName;
this.model = model;
this.energyReserve = energyReserve;
this.ap = ap;
}
/**

Return a new builder with all fields set to default Java values
*/
public static ArmoredCoreBuilder builder() {
return new ArmoredCoreBuilder();
}

/**

Return a new builder with all fields set to the values taken from the given record instance
*/
public static ArmoredCoreBuilder builder(ArmoredCore from) {
return new ArmoredCoreBuilder(from.coreName(), from.model(), from.energyReserve(), from.ap());
}

/**

Return a new ArmoredCore instance with all fields set to the current values in this builder
/
public ArmoredCore build() {
return new ArmoredCore(coreName, model, energyReserve, ap);
}
/*
Set a new value for the {@code coreName} record component in the builder
/
public ArmoredCoreBuilder coreName(String coreName) {
this.coreName = coreName;
return this;
}
/*
Set a new value for the {@code model} record component in the builder
/
public ArmoredCoreBuilder model(String model) {
this.model = model;
return this;
}
/*
Set a new value for the {@code energyReserve} record component in the builder
/
public ArmoredCoreBuilder energyReserve(int energyReserve) {
this.energyReserve = energyReserve;
return this;
}
/*
Set a new value for the {@code ap} record component in the builder
*/
public ArmoredCoreBuilder ap(int ap) {
this.ap = ap;
return this;
}
}

  

Default Values

Using @DefaultValue we can directly write the code to set the default value in the generated builder. This allows us to directly write a value or use static methods to set the default builder state.

@RecordBuilder
public record Defaults(
    @DefaultValue("List.of(1,2,3)") List<Integer> list,
    @DefaultValue("24") int num,
    @DefaultValue("\"string val\"") String str,
    @DefaultValue("CustomClass.createDefault()") CustomClass custom) {}

This will generate:

public class DefaultsBuilder {
  private List<Integer> list = List.of(1,2,3);
  private int num = 24;
  private String str = "string val";
  private CustomClass custom = CustomClass.createDefault();

...the rest of the builder
}