I am new at GWT and I have an application which has the following class:
package evaluation.system.shared;
import java.io.Serializable;
import com.google.gwt.user.client.rpc.IsSerializable;
public class Evaluation implements Serializable, IsSerializable{
/**
*
*/
private static final long serialVersionUID = 1L;
private String evaluatorRID;
private String fName;
private String lName;
private double score;
public Evaluation() {
}
public String getEvaluatorRID() {
return evaluatorRID;
}
public void setEvaluatorRID(String evaluateeRID) {
this.evaluatorRID = evaluateeRID;
}
public String getfName() {
return fName;
}
public void setfName(String fName) {
this.fName = fName;
}
public String getlName() {
return lName;
}
public void setlName(String lName) {
this.lName = lName;
}
public double getScore() {
return score;
}
public void setScore(double score) {
this.score = score;
}
public Evaluation(String evaluatorRID, String fName, String lName,
double score) {
this.evaluatorRID = evaluatorRID;
this.fName = fName;
this.lName = lName;
this.score = score;
}
}
and each time I run the application the get the following error:
[ERROR] [evaluationsystem] Line 10: No source code is available for
type evaluation.system.shared.Evaluation; did you forget to inherit a
required module?
And as you can see line 10 is the beginning of the class.
Your help is appreciated!
So I found what the problem is, basically its the class name. I am not sure if GWT was unable to recognize the class Evaluation.java because "evaluation" is also in the package name...
All I know is that it occured to me that this could be causing the problem and when I changed the name it worked perfectly!
Related
I am exploring Google Cloud Dataflow.
I was wondering if automatic conversion between java object or JSON to TableRow can be done.
Just like we can automatically parse JSON to POJO class.
I could not find relevant information.
Hope not to duplicate question.
Will be grateful for any info!
Greetings
I've looking for examples for the same with no luck. I created a POJO class that almost match the schema of the bigquery table and matches the structure of the JSON objects that are the input for the pipeline. Finally, when I have to convert those objects to TableRow, for the nested and repeated values I made something like below, and the conversion was made by the API
TableRow row = new TableRow()
.set("items", c.element().getItems())
.set("orderDate", c.element().getOrderDate())
.set("orderNumber", c.element().getOrderNumber());
Where Item class is part of the Order object :
#JsonProperty("items")
private List<Item> items = null;
This is the code for Item class:
import java.io.Serializable;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import com.fasterxml.jackson.annotation.JsonAnyGetter;
import com.fasterxml.jackson.annotation.JsonAnySetter;
import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.annotation.JsonProperty;
import com.fasterxml.jackson.annotation.JsonPropertyOrder;
#JsonInclude(JsonInclude.Include.NON_NULL)
#JsonPropertyOrder({
"id",
"code",
"detail",
"name",
"shortName",
"description",
"sku",
"quantity",
"category",
"products"
})
public class Item implements Serializable
{
#JsonProperty("id")
private Integer id;
#JsonProperty("code")
private String code;
#JsonProperty("detail")
private String detail;
#JsonProperty("name")
private String name;
#JsonProperty("shortName")
private String shortName;
#JsonProperty("description")
private String description;
#JsonProperty("sku")
private String sku;
#JsonProperty("quantity")
private Integer quantity;
#JsonProperty("category")
private Category category;
#JsonProperty("products")
private List<Product> products = null;
#JsonIgnore
private Map<String, Object> additionalProperties = new HashMap<String, Object>();
private final static long serialVersionUID = -5644586446669059821L;
#JsonProperty("id")
public Integer getId() {
return id;
}
#JsonProperty("id")
public void setId(Integer id) {
this.id = id;
}
#JsonProperty("code")
public String getCode() {
return code;
}
#JsonProperty("code")
public void setCode(String code) {
this.code = code;
}
#JsonProperty("detail")
public String getDetail() {
return detail;
}
#JsonProperty("detail")
public void setDetail(String detail) {
this.detail = detail;
}
#JsonProperty("name")
public String getName() {
return name;
}
#JsonProperty("name")
public void setName(String name) {
this.name = name;
}
#JsonProperty("shortName")
public String getShortName() {
return shortName;
}
#JsonProperty("shortName")
public void setShortName(String shortName) {
this.shortName = shortName;
}
#JsonProperty("description")
public String getDescription() {
return description;
}
#JsonProperty("description")
public void setDescription(String description) {
this.description = description;
}
#JsonProperty("sku")
public String getSku() {
return sku;
}
#JsonProperty("sku")
public void setSku(String sku) {
this.sku = sku;
}
#JsonProperty("quantity")
public Integer getQuantity() {
return quantity;
}
#JsonProperty("quantity")
public void setQuantity(Integer quantity) {
this.quantity = quantity;
}
#JsonProperty("category")
public Category getCategory() {
return category;
}
#JsonProperty("category")
public void setCategory(Category category) {
this.category = category;
}
#JsonProperty("products")
public List<Product> getProducts() {
return products;
}
#JsonProperty("products")
public void setProducts(List<Product> products) {
this.products = products;
}
#JsonAnyGetter
public Map<String, Object> getAdditionalProperties() {
return this.additionalProperties;
}
#JsonAnySetter
public void setAdditionalProperty(String name, Object value) {
this.additionalProperties.put(name, value);
}
}
And this is the schema of the BigQuery table in regards Items, where Item is a RECORD and REPEATED field and also contain a nested RECORD and REPEATED field: products. See the screenshot of the schema
Item schema fields in BQ
Not sure why I have an issue here, but when I save with a CrudRepository with these objects, I get the SerializationException (with no further information). Can someone take a look at my objects and offer me some insight into why they can't serialize? My pom.xml is attached last as well in case that helps somehow. I'm using a Postgres database.
EDIT: The database and now - tables are created, but objects are not creating rows.
The actual CrudRepository interface:
public interface AccountRepository extends CrudRepository<ZanyDishAccount, String> {}
ZanyDishAccount entity:
#Entity
public class ZanyDishAccount {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
private Long id; // internal id of the customer account for a Zany Dish subscription
private String status;
#OneToOne(cascade=CascadeType.ALL, fetch = FetchType.EAGER)
#JoinColumn(name = "company_id")
private Company company;
#OneToOne(cascade=CascadeType.ALL, fetch = FetchType.EAGER)
#JoinColumn(name = "order_id")
private Order order;
public ZanyDishAccount() {}
public ZanyDishAccount(Company company, Order order) {
this.company = company;
this.order = order;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public Company getCompany() {
return company;
}
public void setCompany(Company company) {
this.company = company;
}
public Order getOrder() {
return order;
}
public void setOrder(Order order) {
this.order = order;
}
public String getStatus() {
return status;
}
public void setStatus(String status) {
this.status = status;
}
#Override
public String toString()
{
return "ClassPojo [id = "+id+ ", company = " + company + ", status = " + status + "]";
}
}
Company entity:
#Entity
public class Company {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
Long id;
private String phoneNumber;
private String website;
private String name;
private String uuid;
private String country;
public Company() {}
public Company(String phoneNumber, String website, String name, String uuid, String country) {
this.phoneNumber = phoneNumber;
this.website = website;
this.uuid = uuid;
this.country = country;
}
public String getPhoneNumber ()
{
return phoneNumber;
}
public void setPhoneNumber (String phoneNumber)
{
this.phoneNumber = phoneNumber;
}
public String getWebsite ()
{
return website;
}
public void setWebsite (String website)
{
this.website = website;
}
public String getName ()
{
return name;
}
public void setName (String name)
{
this.name = name;
}
public String getUuid ()
{
return uuid;
}
public void setUuid (String uuid)
{
this.uuid = uuid;
}
public String getCountry ()
{
return country;
}
public void setCountry (String country)
{
this.country = country;
}
#Override
public String toString()
{
return "ClassPojo [phoneNumber = "+phoneNumber+", website = "+website+", name = "+name+", uuid = "+uuid+", country = "+country+"]";
}
}
Order entity:
#Entity
#Table(name = "_order")
public class Order {
#Id
#GeneratedValue(strategy=GenerationType.AUTO)
Long id;
private String pricingDuration;
private Items[] items;
private String editionCode;
public Order() {}
public Order(String pricingDuration, Items[] items, String editionCode) {
this.pricingDuration = pricingDuration;
this.items = items;
this.editionCode = editionCode;
}
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getPricingDuration ()
{
return pricingDuration;
}
public void setPricingDuration (String pricingDuration)
{
this.pricingDuration = pricingDuration;
}
public Items[] getItems ()
{
return items;
}
public void setItems (Items[] items)
{
this.items = items;
}
public String getEditionCode ()
{
return editionCode;
}
public void setEditionCode (String editionCode)
{
this.editionCode = editionCode;
}
#Override
public String toString()
{
return "ClassPojo [pricingDuration = "+pricingDuration+", items = "+items+", editionCode = "+editionCode+"]";
}
}
Thanks for your help!
Mike
Hm, this seems multi-faceted. Let's see if I can help at all. Last thing first...
No tables being created automatically.
I would take a look at this section in Spring's docs for the most basic approach: Initialize a database using Hibernate. For example, spring.jpa.hibernate.ddl-auto: create-drop will drop and re-create tables each time the application runs. Simple and easy for initial dev work. More robust would be leveraging something like Flyway or Liquibase.
Serialization issue
So without logs, and the fact that you have no tables created, the lack of a persistence layer would be the assumed culprit. That said, when you have tables and data, if you do not have a repository for all of the related tables, you'll end up with a StackOverflow error (the serialization becomes circular). For that, you can use #JsonBackReference (child) and #JsonManagedReference (parent). I have been successful using only #JsonBackReference for the child.
Items[]
I'm not sure what Item.class looks like, but that looks like an offensive configuration that I missed the first round.
Change private Items[] items; to private List<Item> items = new ArrayList<Item>();. Annotate with #ElementCollection.
Annotate Item.class with #Embeddable.
I'm using some JavaFX properties in my app:
#Entity(name = "Klanten")
#Table(name = "Klanten")
#NamedQueries({
#NamedQuery(name = "Klanten.findAll", query = "select k from Klanten k")
})
public class Klant implements Serializable {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private int klantId;
#Transient
private final SimpleStringProperty naam = new SimpleStringProperty();
//private String naam;
//private String straat;
#Transient
private final SimpleStringProperty straat = new SimpleStringProperty();
private String telefoon;
private String huisnummer;
private String gsm;
private String woonplaats;
private String email;
private String postcode;
#OneToMany(mappedBy = "Klant", cascade = CascadeType.REMOVE)
private List<Raam> ramen;
public Klant() {
}
public Klant(String naam) {
this.naam.set(naam);
}
#Override
public String toString() {
return this.naam.get();
}
#Access(AccessType.PROPERTY)
#Column(name="naam")
public String getNaam() {
return this.naam.get();
}
public void setNaam(String naam){
this.naam.set(naam);
}
public List<Raam> getRamen() {
return this.ramen;
}
#Id
public int getKlantId() {
return klantId;
}
public void setKlantId(int klantId) {
this.klantId = klantId;
}
#Access(AccessType.PROPERTY)
#Column(name="straat")
public String getStraat() {
return straat.get();
}
public void setStraat(String straat) {
this.straat.set(straat);
}
public String getTelefoon() {
return telefoon;
}
public void setTelefoon(String telefoon) {
this.telefoon = telefoon;
}
public String getHuisnummer() {
return huisnummer;
}
public void setHuisnummer(String huisnummer) {
this.huisnummer = huisnummer;
}
public String getGsm() {
return gsm;
}
public void setGsm(String gsm) {
this.gsm = gsm;
}
public String getWoonplaats() {
return woonplaats;
}
public void setWoonplaats(String woonplaats) {
this.woonplaats = woonplaats;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPostcode() {
return postcode;
}
public void setPostcode(String postcode) {
this.postcode = postcode;
}
public StringProperty naamProperty() {
return naam;
}
public StringProperty straatProperty() {
return straat;
}
}
However when I let JPA generate my database, the column "naam" and "straat" aren't generated. I get no error. How can I resolve this?
I tried all the things listed here:
Possible solution 1
Possible solution 2
These didn't work.
You can try to use regular properties and then have another get method which returns a new SimpleStringProperty, i.e.:
public StringProperty naamProperty() {
return new SimpleStringProperty(naam);
}
public StringProperty straatProperty() {
return new SimpleStringProperty(straat);
}
How can I implement a bidirectional one-to-one mapping using Google Application Engine (GAE) using Java Data Objects (JDO)?
I have a User class which holds contactInfo object and a ContactInfo class that holds a user object
#PersistenceCapable(identityType ="APPLICATION", detachable = "true")
public class User{
#PrimaryKey
#Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Long id;
private String name;
#Persistent(dependent = "true")
private ContactInfo child;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public ContactInfo getChild() {
return child;
}
public void setChild(ContactInfo child) {
this.child = child;
}
}
#PersistenceCapable(identityType ="APPLICATION", detachable = "true")
public class ContactInfo {
#PrimaryKey
#Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key id;
#Persistent(mappedBy = "child")
private User parent;
private String contactDetail;
public Key getId() {
return id;
}
public void setId(Key id) {
this.id = id;
}
public String getContactDetail() {
return contactDetail;
}
public void setContactDetail(String contactDetail) {
this.contactDetail = contactDetail;
}
}
Following error i am getting while testing API from API explorer
com.google.appengine.repackaged.org.codehaus.jackson.map.JsonMappingException: Infinite recursion (StackOverflowError) (through reference chain: com.demo.jdo.ContactInfo[\"user\"]->com.demo.jdo.User[\"contactInfo\"]->com.demo.jdo.ContactInfo[\"user\"]-
Standard JDO 1-1 bidir is simply found from http://www.datanucleus.org/products/accessplatform_3_1/jdo/orm/one_to_one.html#bi
GAE ought to be no different in this respect; last time I used it (maybe 3 yrs ago) they had some tests, think those under here http://code.google.com/p/datanucleus-appengine/source/browse/#svn%2Ftrunk%2Ftests%2Fcom%2Fgoogle%2Fappengine%2Fdatanucleus
Your question provides no definition of what you have tried in terms of annotations
Got the Solution, problem was with wrong use of mappedBy & presence of getter and setter of parent object in child.
#Persistent(mappedBy = "") annotation should only be at non-owner side
In on-owner/ child side there should not be any getter/setter present for owner/parent object.
Working code:
User.java
import javax.jdo.annotations.IdGeneratorStrategy;
import javax.jdo.annotations.IdentityType;
import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;
import javax.jdo.annotations.PrimaryKey;
#PersistenceCapable(identityType = IdentityType.APPLICATION, detachable = "true")
public class User {
#PrimaryKey
#Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Long id;
private String name;
#Persistent(dependent = "true")
private ContactInfo contactInfo;
public Long getId() {
return id;
}
public void setId(Long id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public ContactInfo getContactInfo() {
return contactInfo;
}
public void setContactInfo(ContactInfo contactInfo) {
this.contactInfo = contactInfo;
}
}
ContactInfo.java
import javax.jdo.annotations.IdGeneratorStrategy;
import javax.jdo.annotations.IdentityType;
import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;
import javax.jdo.annotations.PrimaryKey;
import com.google.appengine.api.datastore.Key;
#PersistenceCapable(identityType = IdentityType.APPLICATION, detachable = "true")
public class ContactInfo {
#PrimaryKey
#Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
private Key id;
#Persistent(mappedBy = "contactInfo")
/*
* Important: Do not create getter and setters for this object else
* bidirectional mapping gives error
*/
private User user;
private String contactDetail;
public Key getId() {
return id;
}
public void setId(Key id) {
this.id = id;
}
public String getContactDetail() {
return contactDetail;
}
public void setContactDetail(String contactDetail) {
this.contactDetail = contactDetail;
}
}
Am trying to create a model class to store an Entity in Google App Engine using Eclipse.But when i save my work i get the error message:
org.datanucleus.metadata.MetaDataManager initialiseFileMetaDataForUse.
SEVERE: Class "com.packagename.classname" has been specified with an object-id class javax.jdo.identity.StringIdentity yet no fields have been identified as primary key fields. Please notate using the "primary-key" tag against the fields that should be considered part of the primary key.
If my understanding of JPA is correct, i do not need a primary-key for an entity since i already have a #Id tag.Here is my class.
#Entity
public class MyCLassName {
#Id
#GeneratedValue(strategy = GenerationType.IDENTITY)
private static String userName;
private static String location;
private static Date dateOfBirth;
private static int age;
private static String gender;
private static String teamName;
private static int weight;
//Constructor with arguments
public MyClassName(String userName, String location, String gender, int age, Date DOB, int weight) {
MyClassName.userName = userName;
MyClassName.location = location;
MyClassName.gender = gender;
MyClassName.age=age;
MyClassName = DOB;
MyClassName.weight = weight;
}
//setter methods
public static void setUserName(String userName) {
MyClassName.userName = userName;
}
public static void setLocation(String location) {
MyClassName.location = location;
}
public static void setGender(String gender) {
MyClassName.gender = gender;
}
public static void setAge(int age) {
MyClassName.age = age;
}
public static void setDateOfBirth(Date dateOfBirth) {
MyClassName.dateOfBirth = dateOfBirth;
}
public static void setWeight(int weight) {
MyClassName.weight = weight;
}
//getter methods
public static String getUserName() {
return userName;
}
public static int getWeight() {
return weight;
}
public static String getLocation() {
return location;
}
public static String getGender() {
return gender;
}
public static String getTeamName() {
return teamName;
}
public static Date getDateOfBirth() {
return dateOfBirth;
}
public static int getAge() {
return age;
}
}
What exactly am i doing wrong here?
Your understanding of JPA is partially correct. You do not need to assign the primary key because you have used the #Id and #GeneratedValue annotation. The JPA implementation will automatically generate the primary key value as a long integer. However it still needs a field in which to store this ID value. It is trying to do that in userName. See Java Tutorial ID Generation Type: IDENTITY for example.