#1297 - ENH: Add DtoQuery ... such that we can map native SQL queries automatically into "DTO beans"

src/main/java/io/ebeaninternal/server/dto/DtoBeanManager.java

@@ -0,0 +1,53 @@
+package io.ebeaninternal.server.dto;
+
+import io.ebean.meta.MetaQueryMetric;
+import io.ebeaninternal.metric.MetricFactory;
+import io.ebeaninternal.metric.QueryPlanCollector;
+import io.ebeaninternal.server.type.TypeManager;
+
+import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Manages all the DTO bean descriptors.
+ */
+public class DtoBeanManager {
+
+  private final TypeManager typeManager;
+
+  private final Map<Class, DtoBeanDescriptor> descriptorMap = new ConcurrentHashMap<>();
+
+  public DtoBeanManager(TypeManager typeManager) {
+    this.typeManager = typeManager;
+  }
+
+  /**
+   * Return the descriptor for the given DTO bean class.
+   */
+  @SuppressWarnings("unchecked")
+  public <T> DtoBeanDescriptor<T> getDescriptor(Class<T> dtoType) {
+
+    return descriptorMap.computeIfAbsent(dtoType, this::createDescriptor);
+  }
+
+  private <T> DtoBeanDescriptor createDescriptor(Class<T> dtoType) {
+
+    try {
+      DtoMeta meta = new DtoMetaBuilder(dtoType, typeManager).build();
+      return new DtoBeanDescriptor<>(dtoType, meta);
+    } catch (Exception e) {
+      throw new IllegalStateException(e);
+    }
+  }
+
+  public List<MetaQueryMetric> collectStats(boolean reset) {
+
+    QueryPlanCollector collector = MetricFactory.get().createCollector(reset);
+
+    for (DtoBeanDescriptor value : descriptorMap.values()) {
+      value.collectStats(collector);
+    }
+    return collector.complete();
+  }
+}