/**
* 开始群会话
*/
public SipcRequest createInviteRequest(String uri, Port localPort)
{
SipcRequest req = this.createDefaultSipcRequest(SipcMethod.INVATE);
req.addHeader(SipcHeader.TO, uri);
req.addHeader(SipcHeader.SUPPORTED,"text/html-fragment");
//req.addHeader(SipcHeader.SUPPORTED, "text/plain");
req.addHeader(SipcHeader.SUPPORTED,"multiparty");
req.addHeader(SipcHeader.SUPPORTED,"nudge");
req.addHeader(SipcHeader.SUPPORTED,"share-background");
req.addHeader(SipcHeader.SUPPORTED,"fetion-show");
req.setNeedReplyTimes(2); // 需回复两次
//正文是一些固定的参数
StringBuffer buffer = new StringBuffer();
buffer.append("v=0\r\n");
buffer.append("o=-0 0 IN "+localPort.toString()+"\r\n");
buffer.append("s=session\r\n");
buffer.append("c=IN IP4 "+localPort.toString()+"\r\n");
buffer.append("t=0 0\r\n");
buffer.append("m=message "+Integer.toString(localPort.getPort())+" sip "+uri);
req.setBody(new SipcBody(buffer.toString()));
return req;
}