io.klerch.alexa.tellask.util.resource.ResourceUtteranceReader.java Source code

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Here is the source code for io.klerch.alexa.tellask.util.resource.ResourceUtteranceReader.java

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/**
 * Created by Kay Lerch (https://twitter.com/KayLerch)
 *
 * Contribute to https://github.com/KayLerch/alexa-skills-kit-tellask-java
 *
 * Attached license applies.
 * This source is licensed under GNU GENERAL PUBLIC LICENSE Version 3 as of 29 June 2007
 */
package io.klerch.alexa.tellask.util.resource;

import io.klerch.alexa.tellask.schema.UtteranceReader;
import org.apache.commons.lang3.Validate;

import java.io.InputStream;
import java.net.URL;

/**
 * An implementation to the UtteranceReader interface which encapsulates
 * logic of reading out a set of utterances from the the class-loader. Thus
 * it expects YAML files (utterances.yml) in the resources-directory of your
 * skill project. It looks for this YAML file in directories whose name equals the locale coming in
 * from the speechlet request (e.g. /en-US/utterances.yml). You could provide
 * a leading path over the constructor to have your files stored like e.g.
 * /my/leading/path/en-US/utterances.yml). In addition by overriding the resourceLocation
 * you could add some trailing path to have something like this
 * /my/leading/path/en-US/my/trailing/path/utterances.yml
 * That said it is possible to provide utterances for different locales just
 * by having those files in the right place.
 */
public class ResourceUtteranceReader implements UtteranceReader {
    /**
     * The default resource location. This is just the trailing portion of
     * the qualified resource path.
     */
    public static final String DEFAULT_RESOURCE_LOCATION = "/utterances.yml";
    /**
     * The default leading path. This is the portion in front of the locale
     * folder.
     */
    public static final String DEFAULT_LEADING_PATH = "/";
    private final String leadingPath;
    private String resourceLocation = DEFAULT_RESOURCE_LOCATION;

    /**
     * New reader for classloader-resources. Note that a
     * fully qualified path is a concatenation of the leading path (set in the constructor),
     * the locale (given to the read-method) and the trailing resource location containing the actual filename (can be overridden
     * by setting resourceLocation or providing the the constructor as well).
     * You may end up with something like /my/leading/path/en-US/my/trailing/path/utterances.yml
     * where "en-US" is the only portion you cannot influence as it comes with the locale of
     * a speechlet request.
     */
    public ResourceUtteranceReader() {
        this(DEFAULT_LEADING_PATH, DEFAULT_RESOURCE_LOCATION);
    }

    /**
     * New reader for classloader-resources giving it a valid leading path. Note that a
     * fully qualified path is a concatenation of the leading path (set in the constructor),
     * the locale (given to the read-method) and the trailing resource location containing the actual filename (can be overridden
     * by setting resourceLocation or providing the the constructor as well).
     * You may end up with something like /my/leading/path/en-US/my/trailing/path/utterances.yml
     * where "en-US" is the only portion you cannot influence as it comes with the locale of
     * a speechlet request.
     * @param leadingPath leading path to the actual resource (YAML) file
     */
    public ResourceUtteranceReader(final String leadingPath) {
        this(leadingPath, DEFAULT_RESOURCE_LOCATION);
    }

    /**
     * New reader for classloader-resources giving it a valid leading path. Note that a
     * fully qualified path is a concatenation of the leading path (set in the constructor),
     * the locale (given to the read-method) and the trailing resource location containing the actual filename (can be overridden
     * by setting resourceLocation or providing the the constructor as well).
     * You may end up with something like /my/leading/path/en-US/my/trailing/path/utterances.yml
     * where "en-US" is the only portion you cannot influence as it comes with the locale of
     * a speechlet request.
     * @param leadingPath leading path to the actual resource (YAML) file
     * @param resourceLocation the resource location. must end with ".yml"
     */
    public ResourceUtteranceReader(final String leadingPath, final String resourceLocation) {
        setResourceLocation(resourceLocation);

        final StringBuilder sb = new StringBuilder();

        sb.append(leadingPath.startsWith("/") ? leadingPath.substring(1) : leadingPath);

        if (!leadingPath.endsWith("/"))
            sb.append("/");

        this.leadingPath = sb.toString();
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getLeadingPath() {
        return leadingPath;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public String getResourceLocation() {
        return this.resourceLocation;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setResourceLocation(final String resourceLocation) {
        Validate.notBlank(resourceLocation, "No resource location is set to read from.");
        Validate.notBlank(resourceLocation.replace("/", ""), "No resource location is set to read from.");
        Validate.isTrue(resourceLocation.endsWith(".yml"), "Resource location must end with .yml");
        this.resourceLocation = resourceLocation.startsWith("/") ? resourceLocation : "/" + resourceLocation;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public ResourceUtteranceReader fromResourceLocation(final String resourceLocation) {
        setResourceLocation(resourceLocation);
        return this;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public InputStream read(final String locale) {
        Validate.notNull(locale, "Locale must not be blank.");

        final String resourcePath = leadingPath + locale + resourceLocation;
        final String resourcePath2 = resourcePath.startsWith("/") ? resourcePath.substring(1) : resourcePath;

        final ClassLoader cl = getClass().getClassLoader();

        Validate.notNull(cl.getResource(resourcePath2),
                "Resource " + resourcePath2 + " does not exist in current context.");

        return cl.getResourceAsStream(resourcePath2);
    }
}