ClassCraft

Zero-boilerplate Design Patterns for Java.

ClassCraft is a compile-time annotation processor: annotate a class (or one of its constructors/fields), and it generates a companion class next to it — no reflection, no runtime dependency on ClassCraft itself, fully debuggable/steppable generated source under target/generated-sources.

Features

@GenerateBuilder

Staged builder on a constructor. Required parameters must be supplied — in declared order — before build() becomes available; @Nullable parameters are optional and can be set in any order afterwards.

public class User {
    @GenerateBuilder
    public User(String name, String email, @Nullable String phone) { ... }
}

User alice = UserBuilder.builder()
    .name("Alice")
    .email("alice@example.com")
    .phone("555-1234")
    .build();

@GenerateDTO

A plain companion class with the same fields, getters (+ setters unless mutable = false), an all-args constructor, and optionally equals()/hashCode()/toString().

@GenerateDTO
public class User { private final String name; private final String email; ... }

UserDTO dto = new UserDTO("Alice", "alice@example.com");

@GenerateMapper

Bidirectional static mapper between two classes with the same (non-@Ignored) fields, using setters or an all-args constructor depending on which the target class provides.

@GenerateMapper(to = "com.example.UserDTO")
public class User { ... }

UserDTO dto = UserMapper.toUserDTO(user);
User restored = UserMapper.toUser(dto);

@GenerateWither

Copy-with-one-field-changed, without a builder or manual field-by-field copying.

@GenerateWither
public class User { ... }

User updated = UserWither.withEmail(alice, "alice@work.example.com");

@GenerateLogger

A structured, reflection-free renderer/logger — complementary to JWeaver's generic runtime object rendering: this one is compile-time and tailored per class.

@GenerateLogger
public class User { ... }

UserLogger.line(user);   // User{name="Alice", email="alice@example.com"} — single line, log-pipeline-safe
UserLogger.tree(user);   // multi-line ASCII tree — for console/debug output
UserLogger.info("User created", user); // SLF4J convenience wrapper, built on line()

Field markers

• @Ignore — skip a field in @GenerateDTO/@GenerateWither/@GenerateMapper/@GenerateLogger.
• @Sensitive — mask a field's value in @GenerateLogger's output instead of reading it (mask attribute, default "***"). Has no effect on the other generators.
• @Nullable — marks a @GenerateBuilder constructor parameter as optional. Also recognizes JSpecify, JSR-305, JetBrains and Checker Framework @Nullable equivalents.

All generator annotations accept a suffix attribute to customize the generated class name (e.g. @GenerateDTO(suffix = "TO") → UserTO instead of UserDTO).

License

Apache License 2.0