Refactoring: project and java package

src/main/java/fr/pavnay/demo/springboot/react/Application.java

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+package fr.pavnay.demo.springboot.react;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.thymeleaf.templateresolver.ServletContextTemplateResolver;
+
+//@EnableOAuth2Sso
+@SpringBootApplication
+public class Application {
+
+	public static void main(String[] args) {
+		SpringApplication.run(Application.class, args);
+	}
+	
+	@Bean
+	public ServletContextTemplateResolver templateResolver() {
+	    ServletContextTemplateResolver resolver = new ServletContextTemplateResolver();
+	    resolver.setPrefix("/templates/");
+	    resolver.setSuffix(".html");
+	    resolver.setTemplateMode("LEGACYHTML5");
+	    resolver.setCacheable(false);
+	    return resolver;
+	}
+}

src/main/java/fr/pavnay/demo/springboot/react/domain/Comment.java

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+package fr.pavnay.demo.springboot.react.domain;
+
+public class Comment {
+
+	private final Long id;
+	private final String author;
+	private final String text;
+	
+	public Comment(Long id, String author, String text) {
+		this.id = id;
+		this.author = author;
+		this.text = text;
+	}
+	public Long getId() {
+		return id;
+	}
+	public String getAuthor() {
+		return author;
+	}
+	public String getText() {
+		return text;
+	}
+}

src/main/java/fr/pavnay/demo/springboot/react/rest/CommentController.java

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+package fr.pavnay.demo.springboot.react.rest;
+
+import java.util.List;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.ResponseBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import fr.pavnay.demo.springboot.react.domain.Comment;
+import fr.pavnay.demo.springboot.react.service.CommentService;
+
+@RestController
+public class CommentController {
+
+	@Autowired
+	private CommentService service;
+	
+	@RequestMapping("/")
+	public String index() {
+		return "Greetings from Spring Boot!";
+	}
+
+	@RequestMapping(value="/api/comments", method=RequestMethod.GET)
+	public @ResponseBody List<Comment> comments() {
+		return service.getAll();
+	}
+
+	@RequestMapping(value="/api/comments", method=RequestMethod.POST)
+	public @ResponseBody List<Comment> comments(
+			@RequestParam(value="id", required=true) Long id, 
+			@RequestParam(value="author", required=true) String author, 
+			@RequestParam(value="text", required=true) String text) {
+		service.add(new Comment(id, author, text));
+		return service.getAll();
+	}
+	
+}

src/main/java/fr/pavnay/demo/springboot/react/service/CommentService.java

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+package fr.pavnay.demo.springboot.react.service;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import javax.annotation.PostConstruct;
+
+import org.springframework.stereotype.Component;
+
+import fr.pavnay.demo.springboot.react.domain.Comment;
+
+@Component
+public class CommentService {
+
+	private List<Comment> comments = new ArrayList<Comment>();
+
+	@PostConstruct
+	void init() {
+		comments.addAll(Arrays.asList(new Comment(1L, "Pete Hunt", "This is one comment"),
+				new Comment(2L, "Jordan Walke", "This is *another* comment")));
+	}
+	
+	public void add(Comment comment) {
+		comments.add(comment);
+	}
+	
+	public List<Comment> getAll() {
+		return comments;
+	}
+}

src/main/java/fr/pavnay/demo/springboot/react/util/JavaScriptEngine.java

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+package fr.pavnay.demo.springboot.react.util;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.nio.charset.Charset;
+import java.nio.charset.StandardCharsets;
+import java.util.function.Function;
+
+import javax.script.Invocable;
+import javax.script.ScriptEngine;
+import javax.script.ScriptEngineManager;
+import javax.script.ScriptException;
+
+public class JavaScriptEngine {
+
+	private final ScriptEngine scriptEngine = new ScriptEngineManager().getEngineByName("nashorn");
+
+	public JavaScriptEngine polyfillToNashorn() {
+		this.loadFromClassPath("static/js/nashorn-polyfill.js");
+		return this;
+	}
+
+	public JavaScriptEngine eval(String script) {
+		try {
+			this.scriptEngine.eval(script);
+		} catch (ScriptException e) {
+			throw new IllegalStateException("Failed to eval " + script + "!", e);
+		}
+		return this;
+	}
+
+	public JavaScriptEngine loadFromClassPath(String file) {
+		try {
+			this.scriptEngine.eval(readFromClassPath(file));
+		} catch (ScriptException e) {
+			throw new IllegalStateException("Failed to loadFromClassPath " + file + "!", e);
+		}
+		return this;
+	}
+
+	public Object invokeFunction(String functionName, Object... args) {
+		try {
+			return ((Invocable) this.scriptEngine).invokeFunction(functionName, args);
+		} catch (ScriptException | NoSuchMethodException e) {
+			throw new IllegalArgumentException("Failed to invoke " + functionName, e);
+		}
+	}
+
+	public <T> T invokeFunction(String functionName, Function<Object, T> converter, Object... args) {
+		return converter.apply(invokeFunction(functionName, args));
+	}
+
+	private String readFromClassPath(String path) {
+		try (InputStream in = getClass().getClassLoader().getResourceAsStream(path)) {
+			if (in == null) {
+				throw new IllegalArgumentException(path + " is not found!");
+			}
+			return copyToString(in, StandardCharsets.UTF_8);
+		} catch (IOException e) {
+			throw new IllegalStateException("Failed to read " + path, e);
+		}
+	}
+
+	private static String copyToString(InputStream in, Charset charset) throws IOException {
+		StringBuilder out = new StringBuilder();
+		try (InputStreamReader reader = new InputStreamReader(in, charset);) {
+			char[] buffer = new char[4096];
+			int bytesRead = -1;
+			while ((bytesRead = reader.read(buffer)) != -1) {
+				out.append(buffer, 0, bytesRead);
+			}
+			return out.toString();
+		}
+	}
+}

src/main/java/fr/pavnay/demo/springboot/react/web/ViewController.java

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+package fr.pavnay.demo.springboot.react.web;
+
+import java.util.List;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import fr.pavnay.demo.springboot.react.domain.Comment;
+import fr.pavnay.demo.springboot.react.service.CommentService;
+import fr.pavnay.demo.springboot.react.util.JavaScriptEngine;
+
+@Controller
+public class ViewController {
+
+	@Autowired
+	private CommentService service;
+
+	@Bean
+	JavaScriptEngine nashornEngine() {
+		return new JavaScriptEngine().polyfillToNashorn()
+				.loadFromClassPath("static/js/vendors.bundle.js")
+				.loadFromClassPath("static/js/app.bundle.js");
+	}
+	
+	@Autowired
+	ObjectMapper objectMapper;
+	@Autowired
+	JavaScriptEngine nashorn;
+
+	@RequestMapping("/greeting")
+	public String greeting(@RequestParam(value = "name", required = false, defaultValue = "World") String name,
+			Model model) {
+		model.addAttribute("name", name);
+		return "greeting";
+	}
+
+	@RequestMapping("/index")
+	public String index(Model model) throws JsonProcessingException {
+		List<Comment> comments = service.getAll();
+		String markup = nashorn.invokeFunction("renderServer", String::valueOf, comments);
+		String data = objectMapper.writeValueAsString(comments);
+		model.addAttribute("markup", markup);
+		model.addAttribute("data", data);
+		return "index";
+	}
+}