verteilte-systeme-bsc-ai-ex.../VerteilteSysteme-Examples/src/verteiltesysteme/aws/TCPTimeCounterRESTService.java

/* Beispiel angelehnt an http://www.torsten-horn.de/techdocs/jee-rest.htm */
package verteiltesysteme.aws;

import javax.ws.rs.*;
import javax.ws.rs.core.MediaType;

import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.AmazonS3ClientBuilder;

@Path(TCPTimeCounterRESTService.webContextPath)
public class TCPTimeCounterRESTService {
	static final String webContextPath = "/counter";
	static final String bucketName = "vertsys-counter";
	static final String dnsNameELB = "VertSys-ELB1-b88aad9416b2929b.elb.eu-central-1.amazonaws.com";

	private Long getCounter() {
		// Verbindung zu S3
		AmazonS3 s3Client = AmazonS3ClientBuilder.defaultClient();
		String region = s3Client.getRegionName();
		return new Long(s3Client.getObjectAsString(bucketName, region));
	}

	private boolean setCounter(Long counter) {
		// Verbindung zu S3
		AmazonS3 s3Client = AmazonS3ClientBuilder.defaultClient();
		String region = s3Client.getRegionName();
		s3Client.putObject(bucketName, region, new Long(counter).toString());
		return true;
	}

	@GET
	@Produces(MediaType.TEXT_PLAIN)
	public String getCounterPlain() {
		return "Plain-Text: " + getCounter();
	}

	@GET
	@Produces(MediaType.TEXT_HTML)
	public String getCounterHtml() {
		return "<html><head><title>TCPTimeCounter REST Service</title>" +
				"<meta http-equiv=\"refresh\" content=\"5\"/></head><body>" +
				"<h2>Verteilte Systeme HS Fulda - TCPTimeCounter REST Service</h2>"+
				"<p><b>HTML-Output:</b> " + getCounter() + "</p></body></html>";
	}

	@GET
	@Produces(MediaType.APPLICATION_JSON)
	public String getCounterJson() {
		return "{\n  \"type\": \"JSON\",\n  \"output\": \"" + getCounter() + "\"\n}";
	}

	@POST
	@Consumes(MediaType.TEXT_PLAIN)
	@Produces(MediaType.TEXT_PLAIN)
	public String incrCounterPlain(@FormParam("input") String input) {
		Long currentCounterValue = getCounter();
		currentCounterValue = currentCounterValue + (new Long(input)).longValue();
		setCounter(currentCounterValue);
		return "Plain-Text: TCPTimeCounter counter increased by " + input + " to " + currentCounterValue;
	}

	@POST
	@Consumes(MediaType.APPLICATION_FORM_URLENCODED)
	@Produces(MediaType.TEXT_HTML)
	public String incrCounterHtml(@FormParam("input") String input) {
		Long currentCounterValue = getCounter();
		currentCounterValue = currentCounterValue + (new Long(input)).longValue();
		setCounter(currentCounterValue);
		return "<html><head><title>TCPTimeCounter REST Service</title></head></body>" +
				"<h2>Verteilte Systeme HS Fulda - TCPTimeCounter REST Service</h2>" +
				"<p><b>HTML-Output:</b> counter increased by " +
				input + " to " + currentCounterValue + "</p>" +
				"<form method=POST action=\"http://" + dnsNameELB + ":36042/counter\">" +
				"<input name=\"input\" value=\"\"></form></body></html>";
	}

	@POST
	@Consumes(MediaType.TEXT_PLAIN)
	@Produces(MediaType.APPLICATION_JSON)
	public String incrCounterJson(@QueryParam("input") String input) {
		Long currentCounterValue = getCounter();
		currentCounterValue = currentCounterValue + (new Long(input)).longValue();
		setCounter(currentCounterValue);
		return "{\n  \"type\": \"JSON\",\n  \"output\": \"Plain-Text: TCPTimeCounter counter increased by " + input
				+ " to " + currentCounterValue + "\"\n}";
	}

}