I have an Android project and an app engine connected project. I am using the following: JPA v2, App Engine 1.7.6, Java 1.7 compiler, Eclipse 4.2 Juno, EclipseLink 2.4.x
I am using Cloud sql db. I am able to connect successfully in the JPA and DB Persective window and query data back ok. I have set up my app engine to have the SQL Development to be connected to my CLOUD Sql db.
I have one table defined as follows:
CREATE Table Test(codeid varchar(3) NOT NULL,codedesc varchar(20) NOT NULL,PRIMARY KEY (codeid));
The Entity class is as follows:
import java.io.Serializable;
import javax.persistence.*;
@Entity
public class Test implements Serializable {
private static final long serialVersionUID = 1L;
@Id
private String codeid;
private String codedesc;
public Test() {
}
public String getCodeid() {
return this.codeid;
}
public void setCodeid(String codeid) {
this.codeid = codeid;
}
public String getCodedesc() {
return this.codedesc;
}
public void setCodedesc(String codedesc) {
this.codedesc = codedesc;
}
}
the endpoint class is as follows:
@Api(name = "testendpoint" , version = "v1")
public class TestEndpoint {
/**
* This method lists all the entities inserted in datastore.
* It uses HTTP GET method and paging support.
*
* @return A CollectionResponse class containing the list of all entities
* persisted and a cursor to the next page.
*/
@ApiMethod( httpMethod = "GET", name = "listtest.list", path = "ch/list")
@SuppressWarnings({ "unchecked", "unused" })
public CollectionResponse<Test> listTest(
@Nullable @Named("cursor") String cursorString,
@Nullable @Named("limit") Integer limit) {
EntityManager mgr = null;
Cursor cursor = null;
List<Test> execute = null;
try {
mgr = getEntityManager();
Query query = mgr.createQuery("select x from Test x");
if (cursorString != null && cursorString != "") {
cursor = Cursor.fromWebSafeString(cursorString);
query.setHint(JPACursorHelper.CURSOR_HINT, cursor);
}
if (limit != null) {
query.setFirstResult(0);
query.setMaxResults(limit);
}
execute = (List<Test>) query.getResultList();
cursor = JPACursorHelper.getCursor(execute);
if (cursor != null)
cursorString = cursor.toWebSafeString();
// Tight loop for fetching all entities from datastore and accomodate
// for lazy fetch.
for (Test obj : execute);
}
finally
{
mgr.close();
}
return CollectionResponse.<Test> builder().setItems(execute).setNextPageToken (cursorString).build();
}
private boolean containsCodeheader(Test test) {
EntityManager mgr = getEntityManager();
boolean contains = true;
try {
Test item = mgr
.find(Test.class, test.getCodeid());
if (item == null) {
contains = false;
}
} finally {
mgr.close();
}
return contains;
}
private static EntityManager getEntityManager() {
return EMF.get().createEntityManager();
}
}
persistence.xml looks as follows:
<?xml version="1.0" encoding="UTF-8" ?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence
http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd" version="2.0">
<persistence-unit name="transactions-optional" transaction-type="RESOURCE_LOCAL">
<provider></provider>
<class>com.testApp.Test</class>
<properties>
<property name="datanucleus.NontransactionalRead" value="true"/>
<property name="datanucleus.NontransactionalWrite" value="true"/>
<property name="datanucleus.ConnectionURL" value="appengine"/>
What I am trying to do is run my endpoint to get a list of records back . I When I run the following I dont get any errors in the console.
localhost:8888/_ah/api/testendpoint/v1/ch/list
I get the follwoing in the Google Chrome when I know there are records in my table.
{
"items" : [ ]
}
Please let me know if you need more info.
I have carried out further testing and found my above example works for another test app engine project I created before from scratch. A difference I have found is, when I run the broken app engine locally I get the following warning in the Console window which I dont in the working test app:
The backing store, \war\WEB-INF\appengine-generated\local_db.bin, does not exist. It will be created.
