public String getPortletId(String portletName, String servletContextName) {
    String portletId = portletName;

    if (Validator.isNotNull(servletContextName)) {
      if (servletContextName.startsWith("/")) {
        servletContextName = servletContextName.substring(1);
      }
      portletId = portletId.concat(PortletConstants.WAR_SEPARATOR).concat(servletContextName);
    }

    portletId = PortalUtil.getJsSafePortletId(portletId);
    return portletId;
  }
public String getPortletId(String portletName, String servletContextName) {
    String portletId = portletName;

    if (Validator.isNotNull(servletContextName)) {
      if (servletContextName.startsWith("/")) {
        servletContextName = servletContextName.substring(1);
      }
      portletId = portletId.concat(PortletConstants.WAR_SEPARATOR).concat(servletContextName);
    }

    portletId = PortalUtil.getJsSafePortletId(portletId);
    return portletId;
  }
public String getPortletId ( String portletName , String servletContextName ) { String portletId = portletName ; if ( Validator . isNotNull ( servletContextName ) ) { if ( servletContextName . startsWith ( "/" ) ) { servletContextName = servletContextName . substring ( 1 ) ; } portletId = portletId . concat ( PortletConstants . WAR_SEPARATOR ) . concat ( servletContextName ) ; } portletId = PortalUtil . getJsSafePortletId ( portletId ) ; return portletId ; }
copied from
https://github.com/liferay/liferay-portal/blob/master/portal-impl
/src/com/liferay/portal/service/impl/PortletLocalServiceImpl.java

see
http://stackoverflow.com/questions/11151001/how-to-get-portlet-id-using-
the-portlet-name-in-liferay
copied from https : // github . com / liferay / liferay - portal / blob / master / portal - impl / src / com / liferay / portal / service / impl / PortletLocalServiceImpl . java