Advice.java

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package com.sun.grizzly.cometd.bayeux;

/**
 * Bayeux Advise implementation. 
 * See http://svn.xantus.org/shortbus/trunk/bayeux/protocol.txt for the technical
 * details.
 * 
 * The advice system provides a way for servers to inform clients of their
 * preferred mode of client operation. In conjunction with server-enforced limits,
 * Bayeux implementations can prevent resource exhaustion and inelegant failure in
 * several important edge cases. Since transport evenlopes are "pluggable" in
 * order to support differing "on the wire" behaviors, advice values may also vary
 * by transport type, even for the same conditions. What follows is a breif
 * description of the enumerations that are used in advices and their canonical
 * meanings.
 *
 * @author Jeanfrancois Arcand
 */
public class Advice extends VerbBase{
    
    // "none", "retry", "handshake", "recover" (deprecated)
    private static final String[] VALID_RECONNECT =
            new String[] { "none", "retry", "handshake", "recover" };

    private String reconnect = "retry";
    
    
    private Integer interval = 0;


    private Boolean multipleClients = Boolean.FALSE;


    private String[] hosts = null;
    

    private String transport = "\"long-polling\":\t{\n";
    
    
    public Advice() {
        type = Verb.Type.ADVICE;
    }

    public String getReconnect() {
        return reconnect;
    }

    public void setReconnect(String reconnect) {
        this.reconnect = reconnect;
    }

    public Integer getInterval() {
        return interval;
    }

    public void setInterval(Integer interval) {
        this.interval = interval;
    }

    public Boolean getMultipleClients() {
        return multipleClients;
    }

    public void setMultipleClients(Boolean multipleClients) {
        this.multipleClients = multipleClients;
    }

    public String[] getHosts() {
        return hosts;
    }

    public void setHosts(String[] hosts) {
        this.hosts = hosts;
    }
        
    @Override
    public String toString(){
        return toJSON();
    }
    
    public String toJSON() {        
        StringBuilder jsonSb = new StringBuilder(
                "\"advice\":{" 
                + "\"reconnect\":\"" + reconnect + "\","
                + "\"interval\":" + interval + ","
                + "\"multiple-clients\":" + multipleClients
                );

        if (hosts != null && hosts.length > 0) {
            jsonSb.append("\"hosts\":[");
            boolean first_ = true;
            for (int i=0 ;i<hosts.length; i++) {
                if (first_) {
                    first_ = false;
                } else {
                    jsonSb.append(",");
                }

                jsonSb.append("\"").append(hosts[i]).append("\"");
            }
            jsonSb.append("]");
        }

        jsonSb.append("}");         
        return jsonSb.toString();
    }

    public String getTransport() {
        return transport;
    }

    public void setTransport(String transport) {
        this.transport = transport;
    }
        
    public boolean isValid() {
        for (int i=0;i<VALID_RECONNECT.length;i++) {
            if (VALID_RECONNECT[i].equals(reconnect)) {
                return true;
            }
        }
        return false;
    }
}