Simple oembed implementation for Java based on Apache HttpClient
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Simple oembed implementation for Java based on Apache HttpClient

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This is a very simple Java client for consuming Oembed enabled sites.

It uses Jackson for JSON processing and JAXB for XML parsing.

The core service of this project is the OembedService which takes several endpoints. Those endpoints contains url schemes of urls that should be embedded, the URL of the corresponding Oembed endpoint and optional renderers.

java-oembed can be configured to use an ehcache CacheManager instance.

The project is a ready to use configured maven/eclipse project and works nice my java-autolinker.

Important

Since version 0.4.1 this project is Java 8 only. Upgrading from 0.3.x will break stuff. I’ve rewritten nearly everything from scratch, so have a look at the test code or the following small example. The project is now fully tested.

Since version 0.6.1 this project is Java 10 only. In addition, it uses Spring Boots dependency management. Upgrading from 0.5.x will break stuff if you’re not on JDK10 or higher.

Since version 0.7.1 I have changed the API of OembedService and removed Optional<> as input parameter as suggested by various people (Joshua Bloch, Simon Harrer and others). I also took the freedom to apply some checkstyle rules and thus noticing I had several classes from which could have been extended. Those are now final as they should not have been part of the public API.

The project is not yet on the module path because java-oembed uses JAXB for parsing XML which currently leads to a split-package problem.

Usage

Dependency:

java-oembed is available in the Central Repository (since 0.2.10):


<dependency>
    <groupId>eu.michael-simons</groupId>
    <artifactId>java-oembed</artifactId>
    <version>0.5.8</version>
</dependency>

Standalone


public static void main(String... a) {
	final List<OembedEndpoint> endpoints = new ArrayList<>();
	OembedEndpoint endpoint;

	endpoint = new OembedEndpoint();
	endpoint.setName("youtube");
	endpoint.setFormat(Format.json);
	endpoint.setMaxWidth(480);
	endpoint.setEndpoint("https://www.youtube.com/oembed");
	endpoint.setUrlSchemes(Arrays.asList("https?://(www|de)\\.youtube\\.com/watch\\?v=.*"));
	// Optional, specialised renderer, not included here
	// endpoint.setResponseRendererClass(YoutubeRenderer.class);
	endpoints.add(endpoint);

	final OembedService oembedService = new OembedService(new DefaultHttpClient(), null, endpoints, "some-app");
	System.out.println(oembedService.embedUrls("Need some action... <a href=\"https://www.youtube.com/watch?v=dgL6ovr3DJM\">The Hoff!</a>", Optional.empty()));
    }

The builders are gone as you may have noticed. You can add / write them, if you want ;), otherwise i recommend using that stuff in a Spring Boot application like so:

In a Spring Boot application


import ac.simons.oembed.OembedEndpoint;
import ac.simons.oembed.OembedService;
import java.util.List;
import net.sf.ehcache.CacheManager;
import org.apache.http.client.HttpClient;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * @author Michael J. Simons, 2014-12-31
 */
@Configuration
@ConfigurationProperties(prefix = "some-app.oembed")
public class OembedConfig {
    private List<OembedEndpoint> endpoints;

    private boolean autodiscovery = false;

    private String cacheName;

    private Integer defaultCacheAge;

    public List<OembedEndpoint> getEndpoints() {
	return endpoints;
    }

    public void setEndpoints(List<OembedEndpoint> endpoints) {
	this.endpoints = endpoints;
    }

    public boolean isAutodiscovery() {
	return autodiscovery;
    }

    public void setAutodiscovery(boolean autodiscovery) {
	this.autodiscovery = autodiscovery;
    }

    public String getCacheName() {
	return cacheName;
    }

    public void setCacheName(String cacheName) {
	this.cacheName = cacheName;
    }

    public Integer getDefaultCacheAge() {
	return defaultCacheAge;
    }

    public void setDefaultCacheAge(Integer defaultCacheAge) {
	this.defaultCacheAge = defaultCacheAge;
    }

    @Bean
    public OembedService oembedService(HttpClient httpClient, CacheManager cacheManager) {
	final OembedService oembedService = new OembedService(httpClient, cacheManager, endpoints, "some-app");
	oembedService.setAutodiscovery(this.autodiscovery);
	if(this.cacheName != null) {
	    oembedService.setCacheName(cacheName);
	}
	if(this.defaultCacheAge != null) {
	    oembedService.setDefaultCacheAge(defaultCacheAge);
	}
	return oembedService;
    }
}

and achieving the same result as in the stand alone version through the following properties:



# A flag wether autodiscovery of oembed endpoints should be tried. Defaults to false.
# some-app.oembed.autodiscovery =

# The name of the cached used by this service. Defaults to "ac.simons.oembed.OembedService".
# some-app.oembed.cacheName

# Time in seconds responses are cached. Used if the response has no cache_age, defaults to 3600 (one hour).
# some-app.oembed.defaultCacheAge =

some-app.oembed.endpoints[0].name = youtube
some-app.oembed.endpoints[0].endpoint = https://www.youtube.com/oembed
some-app.oembed.endpoints[0].maxWidth = 480
some-app.oembed.endpoints[0].urlSchemes[0] = https?://(www|de)\\.youtube\\.com/watch\\?v=.*
# some-app.oembed.endpoints[0].responseRendererClass = de.dailyfratze.text.oembed.YoutubeRenderer