import com.datastax.driver.mapping.annotations.ClusteringColumn; //导入依赖的package包/类
private static String generatePrimaryKey(Class<?> c) throws Exception {
  Field[] fields = c.getFields();

  List<PartitionKey> partitionKeys = new LinkedList<>();

  Map<PartitionKey, String> partitionKeyToFieldName = new HashMap<>();

  List<String> clusterColumns = new LinkedList<>();

  for (Field f : fields) {
    PartitionKey partitionKey = f.getAnnotation(PartitionKey.class);
    ClusteringColumn clusterColumn = f.getAnnotation(ClusteringColumn.class);

    if (partitionKey != null) {
      partitionKeys.add(partitionKey);
      partitionKeyToFieldName.put(partitionKey, getNameOfField(f));
      // partitonKeys.
    }

    if (clusterColumn != null) {
      clusterColumns.add(getNameOfField(f));
    }
  }

  if (partitionKeys.size() == 0) {
    throw new Exception("Partition key annotations are required!");
  }

  String partitonKey =
      partitionKeys.stream().sorted((p1, p2) -> Integer.compare(p1.value(), p2.value()))
          .map((p) -> partitionKeyToFieldName.get(p)).reduce((p1, p2) -> p1 + ", " + p2).get();

  boolean multiPartitionKey = partitionKeys.size() > 1;

  String result = "PRIMARY KEY (";

  if (multiPartitionKey) {
    result += "(";
  }

  result += partitonKey;

  if (multiPartitionKey) {
    result += ")";
  }

  if (clusterColumns != null) {
    result += ", ";
    result += clusterColumns.stream().reduce((c1, c2) -> c1 + ", " + c2).get();
  }

  result += ")";

  return result;
}
 

import com.datastax.driver.mapping.annotations.ClusteringColumn; //导入依赖的package包/类
/**
 * Get the ClusteringColumn annotation for a Table field.
 * @param position the order of the field in the partition key
 * @return the annotation
 */
public static AnnotationSpec getClusteringAnnotation(int position) {
    return AnnotationSpec.builder(ClusteringColumn.class).addMember("value", "$L", position).build();
}