BeanContext.java

package fr.sii.ogham.core.template.context;

import java.util.Map;

import fr.sii.ogham.core.exception.template.BeanContextException;
import fr.sii.ogham.core.exception.template.ContextException;
import fr.sii.ogham.core.exception.util.BeanWrapperException;
import fr.sii.ogham.core.util.BeanUtils;
import fr.sii.ogham.core.util.EqualsBuilder;
import fr.sii.ogham.core.util.HashCodeBuilder;
import fr.sii.ogham.core.util.bean.MapBeanReadWrapper;

/**
 * Template context that provides variable values using a Java object. Each
 * property name of the object acts as a potential template variable name. Each
 * property value acts as a potential template variable value.
 * 
 * The variables can contain dot character (.) to indicate nested properties. A
 * nested property is a property on a child object. For example, if the provided
 * Java object looks like:
 * 
 * <pre>
 * public class NestedBean {
 *  private SimpleBean nested;
 * 
 *  public NestedBean(SimpleBean nested) {
 *      super();
 *      this.nested = nested;
 *  }
 * 
 *  public SimpleBean getNested() {
 *      return nested;
 *  }
 * 
 *  public static class SimpleBean {
 *      private String value;
 * 
 *      public SimpleBean(String value) {
 *          super();
 *          this.value = value;
 *      }
 * 
 *      public String getValue() {
 *          return value;
 *      }
 * 
 *  }
 * }
 * </pre>
 * 
 * Then the value of the nested object is accessible through the template
 * variable name "nested.value".
 * 
 * @author Aurélien Baudet
 * @see BeanUtils More information about bean conversion
 */
public class BeanContext implements Context {
    /**
     * A Java object that is the source for the variable substitutions
     */
    private Object bean;

    /**
     * Register the bean to use for variable substitutions.
     * 
     * @param bean
     *            the bean to use as source for the variable substitutions
     */
    public BeanContext(Object bean) {
        super();
        this.bean = bean;
    }

    @Override
    public Map<String, Object> getVariables() throws ContextException {
        try {
            return new MapBeanReadWrapper(bean);
        } catch (BeanWrapperException e) {
            throw new BeanContextException("Failed to generate context from bean", bean, e);
        }
    }

    @Override
    public String toString() {
        return bean.toString();
    }
    
    @Override
    public int hashCode() {
        return new HashCodeBuilder().append(bean).hashCode();
    }

    @Override
    public boolean equals(Object obj) {
        return new EqualsBuilder(this, obj).appendFields("bean").isEqual();
    }
}