Thymeleaf MyExpressionObject

ExpressionObjectTest.java

package com.example;

import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.MatcherAssert.assertThat;

import java.util.Arrays;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.Set;

import org.junit.Test;
import org.thymeleaf.TemplateEngine;
import org.thymeleaf.context.Context;
import org.thymeleaf.context.IExpressionContext;
import org.thymeleaf.dialect.IExpressionObjectDialect;
import org.thymeleaf.expression.IExpressionObjectFactory;
import org.thymeleaf.spring4.dialect.SpringStandardDialect;

public class ExpressionObjectTest {

  public static class Yutori {
    public String hello(String name) {
      return "はろー" + name + "！ゆとりだよ！";
    }
  }

  @Test
  public void canUseMyExpressionObject() {
    TemplateEngine engine = new TemplateEngine();
    engine.setDialect(new SpringStandardDialect());
    engine.addDialect(new YutoriDialect());

    String result = engine.process("[[${#yutori.hello('しいば')}]]", new Context());
    assertThat(result, is("はろーしいば！ゆとりだよ！"));
  }

  public static class YutoriExpressionObjectFactory implements IExpressionObjectFactory {

    private static final String YUTORI_EXPRESSION_OBJECT_NAME = "yutori";

    protected static final Set<String> ALL_EXPRESSION_OBJECT_NAMES = Collections
        .unmodifiableSet(new LinkedHashSet<>(Arrays.asList(new String[] { YUTORI_EXPRESSION_OBJECT_NAME })));

    private static final Yutori YUTORI_EXPRESSION_OBJECT = new Yutori();

    @Override
    public boolean isCacheable(String expressionObjectName) {
      return true;
    }

    @Override
    public Set<String> getAllExpressionObjectNames() {
      return ALL_EXPRESSION_OBJECT_NAMES;
    }

    @Override
    public Object buildObject(IExpressionContext context, String expressionObjectName) {
      if (YUTORI_EXPRESSION_OBJECT_NAME.equals(expressionObjectName)) {
        return YUTORI_EXPRESSION_OBJECT;
      }
      return null;
    }

  }

  public static class YutoriDialect implements IExpressionObjectDialect {

    private final IExpressionObjectFactory YUTORI_EXPRESSION_OBJECT_FACTORY = new YutoriExpressionObjectFactory();

    @Override
    public String getName() {
      return "YutoriDialect";
    }

    @Override
    public IExpressionObjectFactory getExpressionObjectFactory() {
      return YUTORI_EXPRESSION_OBJECT_FACTORY;
    }
  }

}