pushlet Event

public class Event implements Protocol, Serializable {

protected Map attributes = new HashMap(3);

public Event(String anEventType) {
this(anEventType, null);
}

//初始化方法 设置事件的时间 类型 属性  这些数据都在map中
public Event(String anEventType, Map theAttributes) {

if (theAttributes != null) {
setAttrs(theAttributes);
}

// Set required field event type
setField(P_EVENT, anEventType);

// Set time in seconds since 1970
setField(P_TIME, System.currentTimeMillis() / 1000);
}

//初始化方法 设置属性  因为没有提供默认的时间类型， 所以属性中必须包含类型信息
public Event(Map theAttributes) {
if (!theAttributes.containsKey(P_EVENT)) {
throw new IllegalArgumentException(P_EVENT + " not found in attributes");
}
setAttrs(theAttributes);
}

public static Event createDataEvent(String aSubject) {
return createDataEvent(aSubject, null);
}

//创建数据事件  设置主题
public static Event createDataEvent(String aSubject, Map theAttributes) {
Event dataEvent = new Event(E_DATA, theAttributes);
dataEvent.setField(P_SUBJECT, aSubject);
return dataEvent;
}

//拿到事件类型
public String getEventType() {
return getField(P_EVENT);
}

//拿到事件主题
public String getSubject() {
return getField(P_SUBJECT);
}

public void setField(String name, String value) {
attributes.put(name, value);
}

public void setField(String name, int value) {
attributes.put(name, value + "");
}

public void setField(String name, long value) {
attributes.put(name, value + "");
}

public String getField(String name) {
return (String) attributes.get(name);
}

/**
* Return field; if null return default.
*/
public String getField(String name, String aDefault) {
String result = getField(name);
return result == null ? aDefault : result;
}

public Iterator getFieldNames() {
return attributes.keySet().iterator();
}

public String toString() {
return attributes.toString();
}

/**
* Convert to HTTP query string.
* 拼出一个http  get请求  id=1&name=xxx&age=13$v=34  类似这样的
*/
public String toQueryString() {
String queryString = "";
String amp = "";
for (Iterator iter = getFieldNames(); iter.hasNext();) {
String nextAttrName = (String) iter.next();
String nextAttrValue = getField(nextAttrName);
queryString = queryString + amp + nextAttrName + "=" + nextAttrValue;
// After first add "&".
amp = "&";
}

return queryString;
}

//转换成xml格式  strict  true的话会把其中value的特殊字符转换成html的格式 < > \' \" \\ &
//转成 <event  id="id"  name="name" />
public String toXML(boolean strict) {
String xmlString = "<event ";
for (Iterator iter = getFieldNames(); iter.hasNext();) {
String nextAttrName = (String) iter.next();
String nextAttrValue = getField(nextAttrName);
xmlString = xmlString + nextAttrName + "=\"" + (strict ? Sys.forHTMLTag(nextAttrValue) : nextAttrValue) + "\" ";
}

xmlString += "/>";
return xmlString;
}

//默认xml不转成html特殊字符
public String toXML() {
return toXML(false);
}

public Object clone() {
// Clone the Event by using copy constructor
return new Event(attributes);
}

/**
* Copy given attributes into event attributes
*/
private void setAttrs(Map theAttributes) {
attributes.putAll(theAttributes);
}
}