Opinionated, modern code style for Java

Goals

Quick Guidelines

Example

@Multiple(annotations = "")
@With(
 several = "property",
 values = {
 "one",
 "two",
 "three"
 })
public class MyClass extends MyBase implements Implementable {
 public static final String CONSTANT_VALUE = "compile-time-constant";
 private static final long CLASS_ID = 1337L;
 private final MyDependency dependency;
 public MyClass(final MyDependency dependency) {
 this.dependency = Objects.requireNonNull(dependency);
 final MyCache myCache = new MyExpiringCache(10, MINUTES);
 final MyOverlyLongName overlyLongInstance
 = new MyOverlyLongName(myCache, "arguments");
 final MyThingWithTooManyArgs = new MyThingWithTooManyArgs(
 myCache,
 overlyLongInstance,
 dependency,
 "and",
 "some",
 "more",
 "arguments");
 }
 public static void doSomethingWithManyParameters(
 final String action,
 final int iterations,
 @Annotated
 final Object payload) {
 if (payload == null) {
 return;
 }
 if (iterations < 0) {
 return;
 }
 for (int i = 0; i < iterations; ++i) {
 call(action, payload);
 }
 callAnotherMethodWithManyParameters(
 action,
 iterations,
 "foo",
 "bar",
 13,
 37);
 }
 public <T> void streams(final Collection<? extends T> elements) {
 final List<T> list = elements.stream()
 .filter(Objects::nonNull)
 .map(x -> transform("mapping", x))
 .collect(Collectors.toList());
 dependency.send(list);
 }
 @Override
 public boolean equals(final Object other) {
 return this == other
 || other instanceof final MyClass that
 && Objects.equals(that.dependency, dependency);
 }
 @Override
 public int hashCode() {
 int hash = Objects.hashCode(dependency);
 hash = 31 * hash + Objects.hashCode(/*another dependency*/);
 return result;
 }
 private static final class NestedClass
 extends AnotherBase
 implements Implementable,
 Nestable {
 private NestedClass() {
 }
 public String getName() {
 return "name";
 }
 public int age() {
 return 42;
 }
 }
}

Best Practices

// avoid:
List<String> names = List.of();
if (config) {
 names = List.of(config.split(","));
}
// prefer:
final List<String> names;
if (config) {
 names = List.of(config.split(","));
} else {
 names = List.of();
}
// or:
final List<String> names = config
 ? List.of(config.split(","));
 : List.of();

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