public void listInstanceGroups(BmrClient client, String clusterId) {
    try {
        // 方法 1. 罗列指定集群ID相关的实例组
        ListInstanceGroupsResponse response1 = client.listInstanceGroups(clusterId);
        // 方法 2. 自定义ListInstanceGroupsRequest对象的查询请求 
        ListInstanceGroupsResponse response2 = client.listInstanceGroups(new ListInstanceGroupsRequest().withClusterId(clusterId));
        for (InstanceGroup instanceGroup: response2.getInstanceGroups()) {
            System.out.println(instanceGroup.getId() + "," +  instanceGroup.getType()
                    + "," + instanceGroup.getType() + "," + instanceGroup.getRequestedInstanceCount()
                    + "," + instanceGroup.getRootDiskSizeInGB() + "," + instanceGroup.getRootDiskMediumType());
            for (CdsItem cdsItem: instanceGroup.getCds()){
                System.out.println("cdsItem " + cdsItem.getSizeInGB() + "," + cdsItem.getMediumType());
            }
        }
    } catch (BceServiceException e){
        System.out.println("List instance group failed: " + e.getErrorMessage());
    }
}

public class InstanceGroup {
    private String id;                                     //实例组ID
    private String instanceType;                           //实例组套餐类型
    private String name;                                   //实例组名称
    private String type;                                   //实例组类型
    private int requestedInstanceCount;                    //请求的实例个数
    private int rootDiskSizeInGB;                          //系统盘容量大小
    private String rootDiskMediumType;                     //系统盘存储介质类型 
    private List<CdsItem> cds;                             //云磁盘信息列表
}

public class CdsItem {
    private int sizeInGB;                                 //云磁盘容量大小
    private String mediumType;                            //云磁盘存储介质 
}

public void modifyInstanceGroups(BmrClient bmrClient, String clusterId, String coreGroupId, String taskGroupId) {
    // 可省略无须修改的实例组
    List<ModifyInstanceGroupConfig> instanceGroups = new ArrayList<ModifyInstanceGroupConfig>();
    // core group
    ModifyInstanceGroupConfig coreGroup = new ModifyInstanceGroupConfig();
    coreGroup.setId(coreGroupId);
    coreGroup.setInstanceCount(4);
    instanceGroups.add(coreGroup);
    // task group
    ModifyInstanceGroupConfig taskGroup = new ModifyInstanceGroupConfig();
    taskGroup.setId(taskGroupId);
    taskGroup.setInstanceCount(2);
    instanceGroups.add(taskGroup);

    String clientToken = UUID.randomUUID().toString();
    try {
        bmrClient.modifyInstanceGroups(
                new ModifyInstanceGroupsRequest()
                        .withClusterId(clusterId)
                        .withInstanceGroups(instanceGroups)
                        .withClientToken(clientToken)
        );
    } catch (BceServiceException e) {
        System.out.println("Modify instance groups failed: " + e.getErrorMessage());
    }
}