answerer: A Java repository from sorra

Answerer's core is migrated to Hasta，a simple library getting rid of code generation

Answerer is the Celtic mythical sword Fragarach that can attack automatically.

Answerer is just a tool without runtime dependencies and won't disturb your project. With Answerer, you can focus on business logics.

You can use it in existing projects. You can also generate a runnable project with a few configurations. The generated codes are straight-forward, readable and debuggable.

Different from the disposable code generated by IDE, Answerer can keep up with your project continuously. When you modify code, Answerer keeps consistent with your modifications. Not afraid of changing requirements or refactoring!

Since it is so, does Answerer devalue developers? No, developers save time in implementing functionality and have more time to make technologies better!

Answerer is under development but its core is ready for use. Currently its core can wire data and its web extension can generate RESTful services.

Features:

Copy or wire bean properties automatically
Compile-time duck type check

Call the autowire method to inject any variable, and it will be wired into returned types automatically (errors will be reported if you injected improper variables). This is more reliable and convenient than Spring.

Your class using autowire needs to add $UserFunction to Javadoc, and you can write code like this:

// User has id, email, password, nickname, avatar, brief
// UserView has id, name, avatar, brief

String email="a@a.com", password="1234", nickname="Fraga", avatar="", brief="";

User user = Wirer.autowire(email, password, nickname, avatar, brief);
UserView uv = Wirer.autowire(user);

// "password=" names the value "abcd"
user = Wirer.autowire(uv, email, "password=", "abcd");

// Collections are also OK
List<User> users = Arrays.asList(user, user);
Collection<UserView> uvs = Wirer.autowire(users);

Note that there is a small difference of property name between two classes. What's more, to generate RESTful services it should know the relationship of entity and DTO. So you need to write a few simple configurations in your source folder like this:

// Written in Java which is refactorable (and YAML is welcome in the future)
import sorra.answerer.api.Config;
class MyConfig extends Config {
  User user; UserView uv;
  {
    map(user.nickname, uv.name); // Marks relationship between property names
    map(user, uv); // Marks relationship between the entitiy User and the DTO UserView
  }
}

If you want to generate RESTful CRUD from a data class, you need to add $EnableRest to Javadoc and run an update command to generate web controllers.

Currently controllers are overwritten at every time you run update, but you can remove $EnableRest to avoid updating controllers (while wiring still works).

Quick start:

Requires JDK 8. There's a demo contain entity and DTO.

1. Build: ./gradlew shadowJar, the jar is created at build/libs/answerer-0.2-all.jar ; the file as-config.properties contains configuration parameters.
1. Generate REST: run java -jar build/libs/answerer-0.2-all.jar update in Answerer folder.
1. Run: run ./gradlew run in example folder. This builds and starts the example web service.
1. Verify: create data by curl -l -H "Content-type: application/json" -X POST -d {} http://localhost:8080/user/new, and open http://localhost:8080/user/all in browser to see the data.

To generate a new project, run java -jar build/libs/answerer-0.2-all.jar create in Answerer folder, then write entity or DTO similar to example, and run update.

Explanation

The built jar accepts command like create or update.

Create a file as-config.properties in your existing project folder, similar to example.

You can add -D parameter like java -jar -Dkey=value answerer.jar update to override the configurations in as-config.properties.

How it works:

Understand user code by syntactical and semantic analysis so that can generate code to cooperate with user code. My Chinese blog explains the technology in detail: https://www.qingjingjie.com/blogs/2

Coming features

support constructors with parameters
TDD friendly design

Features in roadmap

Inject any data or relationship automatically, no matter it is from SQL, NoSQL or even Micro-services.
Lazy loading and Batch loading
Distributed system solution similar to Micro-services

Features to be discussed

A recipes system supporting various third-party frameworks
SQL DSL
Corountine
RAII

sorra/answerer