JEE & JSF14th Part: Creating an abstraction view layer to JSF components and Forms (3/5). Retrieving configuration from resources

0. Introduction

To retrieve information stored in resources files, if the amount of memory to be used is not very high, it is interesting considering a Singleton component.

In a CDI scenario it can be achieved by means of @ApplicationScoped annotation.

1. ComponentParams class

This class populates all components and attribute types. The JsonUtils class is shown in an elder entry.

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package org.ximodante.jsf.component; import java.io.IOException; import java.io.Serializable; import java.util.List; import java.util.Map; import java.util.stream.Collectors; import javax.annotation.PostConstruct; import javax.enterprise.context.ApplicationScoped; import javax.inject.Named; import org.ximodante.utils.json.JsonUtils; import com.fasterxml.jackson.core.type.TypeReference; import lombok.Getter; @Named @ApplicationScoped /** * Loads the components and attribute catalog from resources/config folder * It is a Singleton object and stores a map of components and resources. * * @author Ximo Dante * */ public class ComponentParams implements Serializable{ private static final long serialVersionUID = 1L; @Getter private Map<String,ComponentAttribute> allAttributes; @Getter private Map<String,ComponentType> allComponents; @PostConstruct public void init() { System.out.println("Initializing ComponentParams..."); try { // 1. populate allAttributes List<ComponentAttribute> myListA= JsonUtils.readObject(true, "config/component-attributes.json", new TypeReference<List<ComponentAttribute>>() { } ); allAttributes = myListA.stream() .collect(Collectors .toMap(x -> x.getName(), x -> x)); // 2. Populate allComponents List<ComponentType> myListT= JsonUtils.readObject(true, "config/component-types.json", new TypeReference<List<ComponentType>>() { } ); allComponents = myListT.stream() .collect(Collectors .toMap(x -> x.getName(), x -> x)); } catch (IOException e) { e.printStackTrace(); } } /* public static void main(String[] args) { ComponentParams cp= new ComponentParams(); System.out.println("AllAttributes------"); for (String s:cp.getAllAttributes().keySet()) { System.out.println(s + "=" + cp.getAllAttributes().get(s).toString()); } System.out.println("AllComponents------"); for (String s:cp.getAllComponents().keySet()) { System.out.println(s + "=" + cp.getAllComponents().get(s).toString()); } } */ }