refactoring

Author: Gerald Unterrainer

src/main/java/info/unterrainer/commons/httpserver/daos/BasicQueryBuilder.java

@@ -1,5 +1,8 @@
 package info.unterrainer.commons.httpserver.daos;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import javax.persistence.EntityManager;
 import javax.persistence.EntityManagerFactory;
 
@@ -20,7 +23,7 @@ public class BasicQueryBuilder<P extends BasicJpa, T, R extends BasicQueryBuilde
 	protected String orderByClause = "o.id ASC";
 	protected boolean lockPessimistic = false;
 
-	protected ParamMap parameters = ParamMap.builder().build();
+	protected Map<String, Object> parameters = new HashMap<>();
 
 	/**
 	 * Sets a custom {@link EntityManager}.
@@ -135,16 +138,35 @@ public R clearWhere() {
 	}
 
 	/**
-	 * Clears the order-by-clause and resets it to default.
-	 * <p>
-	 * Default is the empty string.
+	 * Clears the order-by-clause and resets it to an empty string, thus effectively
+	 * clearing the order.
 	 *
 	 * @return an instance of this builder to provide a fluent interface
 	 */
 	public R clearOrderBy() {
+		return orderBy("");
+	}
+
+	/**
+	 * Sets the order-by-clause to the standard-order, which is {@code "o.id ASC"}
+	 * and since this is the default as well, this effectively resets it to default.
+	 *
+	 * @return an instance of this builder to provide a fluent interface
+	 */
+	public R setStandardOrder() {
 		return orderBy(null);
 	}
 
+	/**
+	 * Sets the order-by-clause to the reversed standard-order, which is
+	 * {@code "o.id DESC"}.
+	 *
+	 * @return an instance of this builder to provide a fluent interface
+	 */
+	public R setReversedStandardOrder() {
+		return orderBy("o.id DESC");
+	}
+
 	/**
 	 * Clears the parameters and resets them to default.
 	 * <p>
@@ -167,9 +189,9 @@ public R clearParameters() {
 	 */
 	@SuppressWarnings("unchecked")
 	public R parameters(final ParamMap params) {
-		parameters = params;
+		parameters = params.getParameters();
 		if (this.parameters == null)
-			parameters = ParamMap.builder().build();
+			parameters = new HashMap<>();
 		return (R) this;
 	}
 
@@ -182,7 +204,7 @@ public R parameters(final ParamMap params) {
 	 */
 	@SuppressWarnings("unchecked")
 	public R addParam(final String paramKey, final Object paramValue) {
-		parameters.addParameter(paramKey, paramValue);
+		parameters.put(paramKey, paramValue);
 		return (R) this;
 	}
 
@@ -206,6 +228,9 @@ public R orderBy(final String orderByClause) {
 
 	/**
 	 * Adds an ASC-segment to the order-by-clause.
+	 * <p>
+	 * Since the standard-order is {@code "o.id ASC"} it is advised to call
+	 * {@link #clearOrderBy()} first.
 	 *
 	 * @param field the name of the field ("o.id" or "o.createdOn" for example)
 	 * @return an instance of this builder to provide a fluent interface
@@ -222,6 +247,9 @@ public R asc(final String field) {
 
 	/**
 	 * Adds an DESC-segment to the order-by-clause.
+	 * <p>
+	 * Since the standard-order is {@code "o.id ASC"} it is advised to call
+	 * {@link #clearOrderBy()} first.
 	 *
 	 * @param field the name of the field ("o.id" or "o.createdOn" for example)
 	 * @return an instance of this builder to provide a fluent interface

src/main/java/info/unterrainer/commons/httpserver/daos/JpqlAsyncDao.java

@@ -103,7 +103,7 @@ public List<P> internalGetList(final EntityManager em, final long size, final bo
 				isFirst = false;
 			} else
 				sb.append("OR ");
-			sb.append("state=:state");
+			sb.append("state = :state");
 			sb.append(i);
 			sb.append(" ");
 		}

src/main/java/info/unterrainer/commons/httpserver/daos/JpqlDao.java

@@ -1,6 +1,7 @@
 package info.unterrainer.commons.httpserver.daos;
 
 import java.time.LocalDateTime;
+import java.util.Map;
 import java.util.Map.Entry;
 
 import javax.persistence.EntityManager;
@@ -39,7 +40,7 @@ public ListJson<P> getList(final EntityManager em, final long offset, final long
 				.orderBy(orderByClause)
 				.parameters(params)
 				.build()
-				.getList(offset, size);
+				.getListJson(offset, size);
 	}
 
 	@Override
@@ -120,7 +121,7 @@ public void delete(final EntityManager em, final Long id) {
 	@Override
 	public P getById(final EntityManager em, final Long id) {
 		try {
-			return query().entityManager(em).where("o.id=:id").addParam("id", id).build().getSingle();
+			return query().entityManager(em).where("o.id = :id").addParam("id", id).build().getSingle();
 		} catch (NoResultException e) {
 			return null;
 		}
@@ -142,7 +143,7 @@ public CountQueryBuilder<P, P> countQuery() {
 	}
 
 	<T> TypedQuery<T> getQuery(final EntityManager em, final String selectClause, final String joinClause,
-			final String whereClause, final ParamMap params, final Class<T> type, final String orderBy,
+			final String whereClause, final Map<String, Object> params, final Class<T> type, final String orderBy,
 			final boolean lockPessimistic) {
 		String query = "SELECT ";
 		if (selectClause == null || selectClause.isBlank())
@@ -162,7 +163,7 @@ <T> TypedQuery<T> getQuery(final EntityManager em, final String selectClause, fi
 
 		String msg = query;
 		if (params != null)
-			for (Entry<String, Object> p : params.getParameters().entrySet())
+			for (Entry<String, Object> p : params.entrySet())
 				msg += "\\n  " + p.getKey() + ": " + p.getValue();
 		log.debug(msg);
 
@@ -175,21 +176,21 @@ <T> TypedQuery<T> getQuery(final EntityManager em, final String selectClause, fi
 		if (lockPessimistic)
 			q.setLockMode(LockModeType.PESSIMISTIC_WRITE);
 		if (params != null)
-			for (Entry<String, Object> e : params.getParameters().entrySet())
+			for (Entry<String, Object> e : params.entrySet())
 				q.setParameter(e.getKey(), e.getValue());
 		return q;
 	}
 
 	Query getCountQuery(final EntityManager em, final String selectClause, final String joinClause,
-			final String whereClause, final ParamMap params) {
+			final String whereClause, final Map<String, Object> params) {
 		String query = "SELECT COUNT(" + selectClause + ") FROM %s AS o";
 		if (joinClause != null && !joinClause.isBlank())
 			query += " " + joinClause;
 		if (whereClause != null && !whereClause.isBlank())
 			query += " WHERE " + whereClause;
 		Query q = em.createQuery(String.format(query, this.type.getSimpleName()));
 		if (params != null)
-			for (Entry<String, Object> e : params.getParameters().entrySet())
+			for (Entry<String, Object> e : params.entrySet())
 				q.setParameter(e.getKey(), e.getValue());
 		return q;
 	}

src/main/java/info/unterrainer/commons/httpserver/daos/Query.java

@@ -2,44 +2,62 @@
 
 import java.util.Collections;
 import java.util.List;
+import java.util.function.Function;
 
+import javax.persistence.EntityManager;
+import javax.persistence.EntityManagerFactory;
 import javax.persistence.NoResultException;
+import javax.persistence.NonUniqueResultException;
 import javax.persistence.TypedQuery;
 
 import info.unterrainer.commons.httpserver.jsons.ListJson;
+import info.unterrainer.commons.rdbutils.Transactions;
 import info.unterrainer.commons.rdbutils.entities.BasicJpa;
 import lombok.AccessLevel;
-import lombok.Getter;
 import lombok.RequiredArgsConstructor;
 
 @RequiredArgsConstructor(access = AccessLevel.PACKAGE)
 public class Query<P extends BasicJpa, T> {
 
-	protected final JpqlDao<P> dao;
-	@Getter
-	protected final TypedQuery<T> typedQuery;
-	@Getter
-	protected final javax.persistence.Query countQuery;
+	protected final EntityManagerFactory emf;
+	protected final QueryBuilder<P, T> builder;
+
+	private <V> V wrap(final Function<EntityManager, V> func) {
+		if (builder.entityManager == null)
+			return Transactions.withNewTransactionReturning(emf, em -> func.apply(em));
+		return func.apply(builder.entityManager);
+	}
 
 	/**
-	 * Gets all the rows specified by offset and size as a list.
+	 * Gets all the rows as a {@link ListJson} as returned by a web-service.
+	 * <p>
+	 * The list contains additional information about the data.
+	 *
+	 * @return a {@link ListJson} containing the rows as specified
+	 */
+	public ListJson<T> getListJson() {
+		return wrap(em -> {
+			ListJson<T> r = new ListJson<>();
+			r.setEntries(getList(em));
+			r.setCount((Long) builder.getCountQuery(em).getSingleResult());
+			return r;
+		});
+	}
+
+	/**
+	 * Gets all the rows specified by offset and size as a {@link ListJson} as
+	 * returned by a web-service.
+	 * <p>
+	 * The list contains additional information about the data.
 	 *
 	 * @param offset the row-number to start at
 	 * @param size   the number-of-rows to return
 	 * @return a {@link ListJson} containing the rows as specified
 	 */
-	public ListJson<T> getList(final long offset, final long size) {
+	public ListJson<T> getListJson(final long offset, final long size) {
 		ListJson<T> r = new ListJson<>();
-		int s = Integer.MAX_VALUE;
-		if (size < s)
-			s = (int) size;
-		int o = Integer.MAX_VALUE;
-		if (offset < o)
-			o = (int) offset;
-		List<T> qResult = typedQuery.getResultList();
-		Long cqResult = (Long) countQuery.getSingleResult();
-		r.setEntries(qResult);
-		r.setCount(cqResult);
+		r.setEntries(getList(offset, size));
+		r.setCount((Long) countQuery.getSingleResult());
 		return r;
 	}
 
@@ -49,7 +67,7 @@ public ListJson<T> getList(final long offset, final long size) {
 	 * @return the result-row as a JPA
 	 */
 	public T getFirst() {
-		List<T> r = typedQuery.setMaxResults(1).getResultList();
+		List<T> r = getList(0, 1);
 		if (r.size() == 1) {
 			T jpa = r.get(0);
 			return jpa;
@@ -59,16 +77,12 @@ public T getFirst() {
 
 	/**
 	 * Get the first N rows from this queries' results.
-	 * 
+	 *
 	 * @param count the number of rows to get
 	 * @return the list of the first N result-rows as JPAs
 	 */
 	public List<T> getN(final long count) {
-		int s = Integer.MAX_VALUE;
-		if (count < s)
-			s = (int) count;
-		typedQuery.setMaxResults(s);
-		return typedQuery.getResultList();
+		return getList(0, count);
 	}
 
 	/**
@@ -89,12 +103,44 @@ public T getSingle() {
 	 * @return the list of result-rows as JPAs
 	 */
 	public List<T> getList() {
-		return typedQuery.getResultList();
+		return wrap(em -> getList(em));
+	}
+
+	private List<T> getList(final EntityManager em) {
+		return getList(0, Long.MAX_VALUE);
+	}
+
+	/**
+	 * Gets all the rows specified by offset and size as a list.
+	 *
+	 * @param offset the row-number to start at
+	 * @param size   the number-of-rows to return
+	 * @return a list containing the rows as specified
+	 */
+	public List<T> getList(final long offset, final long size) {
+		return wrap(em -> getList(em, offset, size));
+	}
+
+	private List<T> getList(final EntityManager em, final long offset, final long size) {
+		int s = Integer.MAX_VALUE;
+		if (size < s)
+			s = (int) size;
+		int o = Integer.MAX_VALUE;
+		if (offset < o)
+			o = (int) offset;
+		TypedQuery<T> query = builder.getTypedQuery(em);
+		query.setFirstResult(o);
+		query.setMaxResults(s);
+		return query.getResultList();
 	}
 
 	/**
 	 * Execute a SELECT query that returns multiple result-rows and reverse the
 	 * order of results.
+	 * <p>
+	 * The reversing-process happens after retrieval of the result, since the whole
+	 * list is going to be transferred anyway.<br>
+	 * The list is reversed using {@code Collections.reverse(list)};
 	 *
 	 * @return the reversed list of result-rows as JPAs
 	 */

src/main/java/info/unterrainer/commons/httpserver/daos/QueryBuilder.java

@@ -1,9 +1,9 @@
 package info.unterrainer.commons.httpserver.daos;
 
+import javax.persistence.EntityManager;
 import javax.persistence.EntityManagerFactory;
 import javax.persistence.TypedQuery;
 
-import info.unterrainer.commons.rdbutils.Transactions;
 import info.unterrainer.commons.rdbutils.entities.BasicJpa;
 
 public class QueryBuilder<P extends BasicJpa, T> extends BasicQueryBuilder<P, T, QueryBuilder<P, T>> {
@@ -16,25 +16,19 @@ public class QueryBuilder<P extends BasicJpa, T> extends BasicQueryBuilder<P, T,
 	}
 
 	public Query<P, T> build() {
-		TypedQuery<T> q;
-		if (entityManager != null) {
-			q = dao.getQuery(entityManager, selectClause, joinClause, whereClause, parameters, resultType,
-					orderByClause, lockPessimistic);
-			javax.persistence.Query cq = new CountQueryBuilder<P, T>(emf, dao).entityManager(entityManager)
-					.select(selectClause)
-					.join(joinClause)
-					.where(whereClause)
-					.build();
-			return new Query<>(dao, q, cq);
-		} else {
-			q = Transactions.withNewTransactionReturning(emf, em -> dao.getQuery(entityManager, selectClause,
-					joinClause, whereClause, parameters, resultType, orderByClause, lockPessimistic));
-			javax.persistence.Query cq = new CountQueryBuilder<P, T>(emf, dao).entityManager(entityManager)
-					.select(selectClause)
-					.join(joinClause)
-					.where(whereClause)
-					.build();
-			return new Query<>(dao, q, cq);
-		}
+		return new Query<>(emf, this);
+	}
+
+	TypedQuery<T> getTypedQuery(final EntityManager em) {
+		return dao.getQuery(entityManager, selectClause, joinClause, whereClause, parameters, resultType, orderByClause,
+				lockPessimistic);
+	}
+
+	javax.persistence.Query getCountQuery(final EntityManager em) {
+		return new CountQueryBuilder<P, T>(emf, dao).entityManager(entityManager)
+				.select(selectClause)
+				.join(joinClause)
+				.where(whereClause)
+				.build();
 	}
 }