Java - POJO Builder
- A Java code generator for the builder pattern using annotation processing
Usage
Just annotate your POJOs with the @Builder annotation, like so:
@Builder public class User {
String name;
int age;
Address address;
}
@Builder public class Address {
String street;
String postcode;
String city;
}
When you compile your project, a new Builder class will be generated for each annotated POJO, like so:
public final class UserBuilder {
private String name;
private int age;
private Address address;
public static UserBuilder user() {
return new UserBuilder();
}
public static UserBuilder user(User from) {
UserBuilder builder = new UserBuilder();
builder.name = from.name;
builder.age = from.age;
builder.address = from.address;
return builder;
}
public UserBuilder name(String name) {
this.name = name;
return this;
}
public UserBuilder age(int age) {
this.age = age;
return this;
}
public UserBuilder address(Address address) {
this.address = address;
return this;
}
public UserBuilder address(AddressBuilder addressBuilder) {
this.address = addressBuilder.build();
return this;
}
public User build() {
User user = new User();
user.name = name;
user.age = age;
user.address = address;
return user;
}
}
Using static imports, you can then create those objects as simple as:
User user = user()
.name("Bob The Builder")
.age(25)
.address(
address()
.street("10 Hight Street")
.postcode("WC2")
.city("London"))
.build();
Fields annotated with @Ignore will be ignored.
Example
Check out the sample project for an example implementation.
The sample project is currently an Android module, but it should work with a pure Java project just as well. If somebody knows how to setup an annotation processor for a Java module using Gradle, please let me know. The apt plugin currently supports only Android modules.
Download
Grab it via Gradle:
compile 'com.jenzz.pojobuilder:api:1.0' apt 'com.jenzz.pojobuilder:processor:1.0'You only need to include the api module (contains just the annotations) as a real dependency.
The annotation processor module can be a compile time only dependency. To do that I highly recommend using Hugo Visser's great apt plugin.
License
This project is licensed under the MIT License.