一、查询所有分组

通过Roster来获取所有分组，Roster可以通过connection.getRoster()来得到。

 /**
      * 获取所有组
      *
      * @param roster
      * @return 所有组集合
      */
     public static List<RosterGroup> getGroups(Roster roster) {
         List<RosterGroup> grouplist = new ArrayList<RosterGroup>();
         Collection<RosterGroup> rosterGroup = roster.getGroups();
         Iterator<RosterGroup> i = rosterGroup.iterator();
         while (i.hasNext()) {
             grouplist.add(i.next());
         }
         return grouplist;
     }

二、添加分组

也一样通过roster来添加分组，groupName 为分组名。

 /**
      * 添加一个分组
      *
      * @param roster
      * @param groupName
      * @return
      */
     public static boolean addGroup(Roster roster, String groupName) {
         try {
             roster.createGroup(groupName);
             return true;
         } catch (Exception e) {
             e.printStackTrace();
             return false;
         }
     }

三、查询某个组里面的所有好友

 /**
      * 获取某个组里面的所有好友
      *
      * @param roster
      * @param groupName
      *            组名
      * @return
      */
     public static List<RosterEntry> getEntriesByGroup(Roster roster,
             String groupName) {
         List<RosterEntry> Entrieslist = new ArrayList<RosterEntry>();
         RosterGroup rosterGroup = roster.getGroup(groupName);
         Collection<RosterEntry> rosterEntry = rosterGroup.getEntries();
         Iterator<RosterEntry> i = rosterEntry.iterator();
         while (i.hasNext()) {
             Entrieslist.add(i.next());
         }
         return Entrieslist;
     }

四、查询所有好友信息

 /**
      * 获取所有好友信息
      *
      * @param roster
      * @return
      */
     public static List<RosterEntry> getAllEntries(Roster roster) {
         List<RosterEntry> Entrieslist = new ArrayList<RosterEntry>();
         Collection<RosterEntry> rosterEntry = roster.getEntries();
         Iterator<RosterEntry> i = rosterEntry.iterator();
         while (i.hasNext()) {
             Entrieslist.add(i.next());
         }
         return Entrieslist;
     }

五、获取用户VCard信息

 /**
      * 获取用户VCard信息
      *
      * @param connection
      * @param user
      * @return
      * @throws XMPPException
      */
     public static VCard getUserVCard(XMPPConnection connection, String user)
             throws XMPPException {
         VCard vcard = new VCard();
         vcard.load(connection, user);
         return vcard;
     }

六、获取用户头像信息

通过Vcard来获取用户头像信息，可以把 InputStream 转换为自己想要的类型，InputStream 转Drawable 

这篇文章里可以找到  

 /**
      * 获取用户头像信息
      *
      * @param connection
      * @param user
      * @return
      */
     public static Drawable getUserImage(XMPPConnection connection, String user) {
         ByteArrayInputStream bais = null;
         try {
             VCard vcard = new VCard();
             // 加入这句代码，解决No VCard for
             ProviderManager.getInstance().addIQProvider("vCard", "vcard-temp",
                     new org.jivesoftware.smackx.provider.VCardProvider());

             vcard.load(connection, user+"@"+connection.getServiceName());

             if (vcard == null || vcard.getAvatar() == null)
                 return null;
             bais = new ByteArrayInputStream(vcard.getAvatar());

         } catch (Exception e) {
             e.printStackTrace();
         }
         if (bais == null)
             return null;
         return FormatTools.getInstance().InputStream2Drawable(bais);
     }

七、添加好友（有、无分组）

 /**
      * 添加好友 无分组
      *
      * @param roster
      * @param userName
      * @param name
      * @return
      */
     public static boolean addUser(Roster roster, String userName, String name) {
         try {
             roster.createEntry(userName, name, null);
             return true;
         } catch (Exception e) {
             e.printStackTrace();
             return false;
         }
     }

     /**
      * 添加好友 有分组
      *
      * @param roster
      * @param userName
      * @param name
      * @param groupName
      * @return
      */
     public static boolean addUser(Roster roster, String userName, String name,
             String groupName) {
         try {
             roster.createEntry(userName, name, new String[] { groupName });
             return true;
         } catch (Exception e) {
             e.printStackTrace();
             return false;
         }
     }

八、删除好友

 /**
      * 删除好友
      *
      * @param roster
      * @param userName
      * @return
      */
     public static boolean removeUser(Roster roster, String userName) {
         try {
             if (userName.contains("@")) {
                 userName = userName.split("@")[0];
             }

             RosterEntry entry = roster.getEntry(userName);
             System.out.println("删除好友：" + userName);
             System.out.println("User." + roster.getEntry(userName) == null);
             roster.removeEntry(entry);

             return true;
         } catch (Exception e) {
             e.printStackTrace();
             return false;
         }
     }

九、查询用户 

serverDoMain 为服务器域名

 /**
      * 查询用户
      *
      * @param connection
      * @param serverDomain
      * @param userName
      * @return
      * @throws XMPPException
      */
     public static List<User> searchUsers(XMPPConnection connection,
             String serverDomain, String userName) throws XMPPException {
         List<User> results = new ArrayList<User>();
         System.out.println("查询开始..............." + connection.getHost()
                 + connection.getServiceName());

         UserSearchManager usm = new UserSearchManager(connection);

         Form searchForm = usm.getSearchForm(serverDomain);
         Form answerForm = searchForm.createAnswerForm();
         answerForm.setAnswer("userAccount", true);
         answerForm.setAnswer("userPhote", userName);
         ReportedData data = usm.getSearchResults(answerForm, serverDomain);

         Iterator<Row> it = data.getRows();
         Row row = null;
         User user = null;
         while (it.hasNext()) {
             user = new User();
             row = it.next();
             user.setUserAccount(row.getValues("userAccount").next().toString());
             user.setUserPhote(row.getValues("userPhote").next().toString());

             System.out.println(row.getValues("userAccount").next());
             System.out.println(row.getValues("userPhote").next());
             results.add(user);
             // 若存在，则有返回,UserName一定非空，其他两个若是有设，一定非空
         }
         return results;
     }

十、修改用户头像

 /**
      * 修改用户头像
      *
      * @param connection
      * @param f
      * @throws XMPPException
      * @throws IOException
      */
     public static void changeImage(XMPPConnection connection, File f)
             throws XMPPException, IOException {

         VCard vcard = new VCard();
         vcard.load(connection);

         byte[] bytes;

         bytes = getFileBytes(f);
         String encodedImage = StringUtils.encodeBase64(bytes);
         vcard.setAvatar(bytes, encodedImage);
         vcard.setEncodedImage(encodedImage);
         vcard.setField("PHOTO", "<TYPE>image/jpg</TYPE><BINVAL>" + encodedImage
                 + "</BINVAL>", true);

         ByteArrayInputStream bais = new ByteArrayInputStream(vcard.getAvatar());
         FormatTools.getInstance().InputStream2Bitmap(bais);