Ma generic do even more version of EntityQuery : MyEntityQue

[koenhandekyn]

i want to share with you this generic do-even-more version of EntityQuery

with the below class it's even easier to write EntityQuery objects.


the EJBQL is generated automatically (example FROM Account account).
there is a getExample() method that returns an example instance (for search paramaters as in the seam-gen generated code)
each time setOrder is hit, if the field was the same as the current, the order switches (for asc/desc switching).
the current order can be queried with getReverse


example using MyEntityQuery

@Name("managedRoles")
@Scope(ScopeType.CONVERSATION)
public class ManagedRolesQuery extends MyEntityQuery<Role> {

 private static final String[] RESTRICTIONS = {
 "role.creationPath LIKE concat(#{currentSubscription.targetPath},'%')",
 "role.name LIKE concat(#{managedRoles.example.name},'%')" };


 @Override
 public List<String> getRestrictions() {
 return Arrays.asList(RESTRICTIONS);
 }

}

feedback welcom !

package up.seam;

import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;

import org.jboss.seam.framework.EntityQuery;

import up.util.LangUtil;

public class MyEntityQuery<T> extends EntityQuery {

 // you cannot initialize (results in bug for seam 2.0.0.GA)
 protected T example = null;

 public T getExample() {
 if (example == null) {
 example = createInstance();
 }
 return example;
 }

 public void setExample(final T example) {
 this.example = example;
 }

 protected Boolean reverse = false;

 public Boolean getReverse() {
 return reverse;
 }

 public void setReverse(Boolean reverse) {
 this.reverse = reverse;
 }

 @Override
 public Integer getMaxResults() {
 return 25;
 }

 @Override
 public void setOrder(final String order) {

 System.out.println("REQUEST TO SORT: " + order + ", was " + super.getOrder());
 if (LangUtil.isNotEmpty(order)) {
 if (order.equals(this.getOrder())) {
 this.reverse = !this.reverse;
 } else {
 this.reverse = false;
 }
 super.setOrder(order);
 }
 }

 @Override
 public String getOrder() {
 if (reverse)
 return super.getOrder() + " desc";
 else
 return super.getOrder();
 }

 private static final long serialVersionUID = 1L;


 @Override
 public String getEjbql() {

 final String entityClassName = getEntityClass().getSimpleName();
 // System.out.println(entityClassName);

 final String ejbql = "from "+entityClassName+" "+entityClassName.toLowerCase();
 // System.out.println(ejbql);
 return ejbql;
 }

 public T createInstance() {

 if (getEntityClass() != null) {
 try {
 return getEntityClass().newInstance();
 } catch (Exception e) {
 throw new RuntimeException(e);
 }
 } else {
 return null;
 }
 }

 protected Class<T> entityClass;

 public Class<T> getEntityClass() {
 if (entityClass == null) {
 Type type = getClass().getGenericSuperclass();
 System.out.println("found class " + getClass());
 System.out.println("found type " + type);
 if (type instanceof ParameterizedType) {
 ParameterizedType paramType = (ParameterizedType) type;
 entityClass = (Class<T>) paramType.getActualTypeArguments()[0];
 } else {
 throw new IllegalArgumentException("Could not guess entity class by reflection");
 }
 }
 return entityClass;
 }

}

[koenhandekyn]

this new version below adds methods that generate the default search constraints given a list of fields.

just override getFields and get the constraints for free using getSearchFieldRestrictions

kind regards

koen

package up.seam;

import java.lang.annotation.Annotation;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;

import org.jboss.seam.annotations.Name;
import org.jboss.seam.framework.EntityQuery;

import up.util.LangUtil;

public class MyEntityQuery<T> extends EntityQuery {

 // you cannot initialize (results in bug for seam 2.0.0.GA)
 protected T example = null;

 public T getExample() {
 if (example == null) {
 example = createInstance();
 }
 return example;
 }

 public void setExample(final T example) {
 this.example = example;
 }

 protected Boolean reverse = false;

 public Boolean getReverse() {
 return reverse;
 }

 public void setReverse(Boolean reverse) {
 this.reverse = reverse;
 }

 @Override
 public Integer getMaxResults() {
 return 25;
 }

 @Override
 public void setOrder(final String order) {

 System.out.println("REQUEST TO SORT: " + order + ", was " + super.getOrder());
 if (LangUtil.isNotEmpty(order)) {
 if (order.equals(this.getOrder())) {
 this.reverse = !this.reverse;
 } else {
 this.reverse = false;
 }
 super.setOrder(order);
 }
 }

 @Override
 public String getOrder() {
 if (reverse)
 return super.getOrder() + " desc";
 else
 return super.getOrder();
 }

 private static final long serialVersionUID = 1L;

 @Override
 public String getEjbql() {

 final String entityClassName = getEntityClass().getSimpleName();
 // System.out.println(entityClassName);

 final String ejbql = "from " + entityClassName + " " + entityClassName.toLowerCase();
 // System.out.println(ejbql);
 return ejbql;
 }

 public T createInstance() {

 if (getEntityClass() != null) {
 try {
 return getEntityClass().newInstance();
 } catch (Exception e) {
 throw new RuntimeException(e);
 }
 } else {
 return null;
 }
 }

 protected Class<T> entityClass;

 public Class<T> getEntityClass() {
 if (entityClass == null) {
 Type type = getClass().getGenericSuperclass();
 System.out.println("found class " + getClass());
 System.out.println("found type " + type);
 if (type instanceof ParameterizedType) {
 ParameterizedType paramType = (ParameterizedType) type;
 entityClass = (Class<T>) paramType.getActualTypeArguments()[0];
 } else {
 throw new IllegalArgumentException("Could not guess entity class by reflection");
 }
 }
 return entityClass;
 }

 public List<String> getSearchFields() {
 return null;
 }

 @Override
 public List<String> getRestrictions() {

 if (getSearchFields() == null)
 return null;

 final List<String> searchFieldRestrictions;
 searchFieldRestrictions = new LinkedList<String>();

 final String componentName;
 componentName = getComponentName();

 for (final String field : getSearchFields()) {
 searchFieldRestrictions.add("account." + field + " LIKE concat(#{" + componentName + ".example." + field + "},'%')");
 }

 return searchFieldRestrictions;
 }

 public String getComponentName() {

 final Annotation nameAnnotation = this.getClass().getAnnotation(Name.class);
 Name name = (Name) nameAnnotation;
 return name.value();

 }
}