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

src/main/java/io/ebeaninternal/server/query/dto/DtoQueryEngine.java

@@ -0,0 +1,66 @@
+package io.ebeaninternal.server.query.dto;
+
+import io.ebeaninternal.server.core.DtoQueryRequest;
+import io.ebeaninternal.server.core.Message;
+import io.ebeaninternal.server.persist.Binder;
+
+import javax.persistence.PersistenceException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.Consumer;
+import java.util.function.Predicate;
+
+public class DtoQueryEngine {
+
+  private final Binder binder;
+
+  public DtoQueryEngine(Binder binder) {
+    this.binder = binder;
+  }
+
+  public <T> List<T> findList(DtoQueryRequest<T> request) {
+    try {
+      request.executeSql(binder);
+      List<T> rows = new ArrayList<>();
+      while (request.next()) {
+        rows.add(request.readNextBean());
+      }
+      return rows;
+
+    } catch (Throwable e) {
+      throw new PersistenceException(Message.msg("fetch.error", e.getMessage(), request.getSql()), e);
+    } finally {
+      request.close();
+    }
+  }
+
+  public <T> void findEach(DtoQueryRequest<T> request, Consumer<T> consumer) {
+     try {
+      request.executeSql(binder);
+      while (request.next()) {
+        consumer.accept(request.readNextBean());
+      }
+    } catch (Exception e) {
+      throw new PersistenceException(Message.msg("fetch.error", e.getMessage(), request.getSql()), e);
+
+    } finally {
+      request.close();
+    }
+  }
+
+  public <T> void findEachWhile(DtoQueryRequest<T> request, Predicate<T> consumer) {
+    try {
+      request.executeSql(binder);
+      while (request.next()) {
+        if (!consumer.test(request.readNextBean())) {
+          break;
+        }
+      }
+    } catch (Exception e) {
+      throw new PersistenceException(Message.msg("fetch.error", e.getMessage(), request.getSql()), e);
+
+    } finally {
+      request.close();
+    }
+  }
+}