An opinionated Java Inner Builder Generator

This is an opinionated but simple Java Inner Builder Generator IntelliJ plugin that generates an inner builder for a given class.

Based from InnerBuilder with stripped down features.

1. Generates builder method for final fields that are not initialized, static fields are excluded
2. Generates static builder() method inside the parent class
3. Uses field names as setters in the builder
4. Detects collection types and generates addTo... method for them if they are initialized

Optional features:

1. Generates toBuilder() method to convert the object to a builder
2. Generates validate() method to validate the fields before building the object

Example

Initial

public class Person {
    static String m = "ME";
    private static final Logger logger = Logger.getLogger("test");
    private final String name;
    private final int age;
    private String lastName;

    private List<String> list;

    private Set<String> set;

    private final List<Address> addresses = new ArrayList<>();

}

Generates

public class Person {
    static String m = "ME";
    private static final Logger logger = Logger.getLogger("test");
    private final String name;
    private final int age;
    private String lastName;

    private List<String> list;

    private Set<String> set;

    private final List<Address> addresses;

    private Person(Builder builder) {
        name = builder.name;
        age = builder.age;
        lastName = builder.lastName;
        list = builder.list;
        set = builder.set;
        addresses = builder.addresses;
    }

    public static Builder builder() {
        return new Builder();
    }

    public Builder toBuilder() {
        Builder builder = new Builder();
        builder.name = this.name;
        builder.age = this.age;
        builder.lastName = this.lastName;
        builder.list = this.list;
        builder.set = this.set;
        builder.addresses = this.addresses;
        return builder;
    }

    public static final class Builder {
        private String name;
        private int age;
        private String lastName;
        private List<String> list;
        private Set<String> set;
        private List<Address> addresses = new ArrayList<>();

        private Builder() {
        }

        public Builder name(String name) {
            this.name = name;
            return this;
        }

        public Builder age(int age) {
            this.age = age;
            return this;
        }

        public Builder lastName(String lastName) {
            this.lastName = lastName;
            return this;
        }

        public Builder list(List<String> list) {
            this.list = list;
            return this;
        }

        public Builder set(Set<String> set) {
            this.set = set;
            return this;
        }

        public Builder addToAddresses(Address e) {
            this.addresses.add(e);
            return this;
        }

        private void validate() {
        }

        public Person build() {
            validate();
            return new Person(this);
        }
    }
}

Supports Java record classes

record Address(Person person, List<String> streets, String city) {
    static String m = "ME";

}

Generates

record Address(Person person, List<String> streets, String city) {
    static String m = "ME";

    public static Builder builder() {
        return new Builder();
    }

    public Builder toBuilder() {
        Builder builder = new Builder();
        builder.person = this.person;
        builder.streets = this.streets;
        builder.city = this.city;
        return builder;
    }

    public static final class Builder {
        private Person person;
        private List<String> streets;
        private String city;

        private Builder() {
        }

        public Builder person(Person person) {
            this.person = person;
            return this;
        }

        public Builder streets(List<String> streets) {
            this.streets = streets;
            return this;
        }

        public Builder city(String city) {
            this.city = city;
            return this;
        }

        private void validate() {
        }

        Address build() {
            validate();
            return new Address(person, streets, city);
        }
    }
}

Installation

1. Download plugin zip file from Releases
2. Open IntelliJ IDEA, go to File -> Settings -> Plugins
3. Click on the gear icon and select Install Plugin from Disk...
4. Select the downloaded zip file and click OK