BasicCoapResponse.java

package org.ws4d.coap.messages;

import org.ws4d.coap.interfaces.CoapResponse;

/**
 * @author Christian Lerche <christian.lerche@uni-rostock.de>
 */

public class BasicCoapResponse extends AbstractCoapMessage implements CoapResponse {
	CoapResponseCode responseCode;

	public BasicCoapResponse(byte[] bytes, int length){
		this(bytes, length, 0);
	}
	
	public BasicCoapResponse(byte[] bytes, int length, int offset){
		serialize(bytes, length, offset);
		/* check if response code is valid, this function throws an error in case of an invalid argument */
		responseCode = CoapResponseCode.parseResponseCode(this.messageCodeValue);
		
		//TODO: check integrity of header options
	}

	/* token can be null */
	public BasicCoapResponse(CoapPacketType packetType, CoapResponseCode responseCode, int messageId, byte[] requestToken){
		this.version = 1;
		
		this.packetType = packetType;
		
		this.responseCode = responseCode;
		if (responseCode == CoapResponseCode.UNKNOWN){
			throw new IllegalArgumentException("UNKNOWN Response Code not allowed");
		}
		this.messageCodeValue = responseCode.getValue();
		
		this.messageId = messageId;		
		
		setToken(requestToken);
	}
	
	
	public CoapResponseCode getResponseCode() {
		return responseCode;
	}

	public void setMaxAge(int maxAge){
		if (options.optionExists(CoapHeaderOptionType.Max_Age)){
			throw new IllegalStateException("Max Age option already exists");
		}
		if (maxAge < 0){
			throw new IllegalStateException("Max Age MUST be an unsigned value");
		}
		options.addOption(CoapHeaderOptionType.Max_Age, long2CoapUint(maxAge));
	}
	
    public long getMaxAge(){
    	CoapHeaderOption option = options.getOption(CoapHeaderOptionType.Max_Age);
    	if (option == null){
    		return -1;
    	}
      	return coapUint2Long((options.getOption(CoapHeaderOptionType.Max_Age).getOptionData()));
    }
	
    public void setETag(byte[] etag){
    	if (etag == null){
    		throw new IllegalArgumentException("etag MUST NOT be null");
    	}
    	if (etag.length < 1 || etag.length > 8){
    		throw new IllegalArgumentException("Invalid etag length");
    	}
    	options.addOption(CoapHeaderOptionType.Etag, etag);
    }
    
    public byte[] getETag(){
    	CoapHeaderOption option = options.getOption(CoapHeaderOptionType.Etag);
    	if (option == null){
    		return null;
    	}
    	return option.getOptionData();
    }

	public boolean isRequest() {
		return false;
	}

	public boolean isResponse() {
		return true;
	}

	public boolean isEmpty() {
		return false;
	}
	
    @Override
	public String toString() {
    	return packetType.toString() + ", " + responseCode.toString() + ", MsgId: " + getMessageID() +", #Options: " + options.getOptionCount(); 
	}

    public void setResponseCode(CoapResponseCode responseCode) {
    	if (responseCode != CoapResponseCode.UNKNOWN){
    		this.responseCode = responseCode;
    		this.messageCodeValue = responseCode.getValue();
		}
	}
}