I have an interface Shape
public interface Shape {
String draw();
}
And two implementations for the above Shape interface
#Component("triangle")
public class Triangle implements Shape {
public String draw() {
return "drawing Triangle";
}
}
and
#Component("circle")
public class Circle implements Shape {
public String draw() {
return "Drawing Circle";
}
}
In my client code if I have to decide which Shape class to use at run time based on Qualifier
#Autowired
private Shape shape;
#GET
#Produces(MediaType.TEXT_HTML)
#Path("/shape")
public String getShape(#PathParam("type")
String type) {
String a = shape.draw();
return a;
}
How to do it?
I want to pass "type" which I get as a pathparam to decide which Shape object to be injected at run time. Please help me in resolving this issue.
I could figure out one way of getting around this by injecting ApplicationContext in the client code.
#Autowired
private ApplicationContext appContext;
And looking up for the bean with the help of getBean method:
#GET
#Produces(MediaType.TEXT_HTML)
#Path("/shape/{type}")
public String getShape(#PathParam("type")
String type) {
Shape shape = appContext.getBean(type, Shape.class);
return shape.draw();
}
I hope this would help someone :)
Related
I am trying to read value from properties file using #value as follows.
#Value("${abc}")
private String abc;
public List<Record> fetchRecords(String label, String predicate) {
System.out.println(abc);
}
but value of abc is coming as null. Whereas when I try to print the same using #PostConstruct, I am getting the expected value.
#PostConstruct
public void postconstruct() {
System.out.println(abc);
}
Any lead why I am not able to get the value in fetchRecords() method?
For reference, here goes the code
#Component
public class AuditRecord {
private String subject;
private String predicate;
private String oldObject;
private String newObject;
private String readOnlyAuthInfo;
#Value("${registry.system.base}")
private String registrySystemContext;
public void record(DatabaseProvider provider) throws AuditFailedException {
System.out.println("---registrySystemContext value showing null here---"+registrySystemContext);
...
}
#PostConstruct
public void postconstruct() {
System.out.println("---registrySystemContext value showing here as expected---"+registrySystemContext);
}
}
The way I am calling is as follows:
#Component
public class RegistryDaoImpl implements RegistryDao {
...
private void addOrUpdateVertexAndEdge(Vertex v, Vertex dbVertex, GraphTraversalSource dbGraph, String methodOrigin){
...
AuditRecord record = new AuditRecord();
record
.subject(dbVertex.label())
.predicate(e.label())
.oldObject(null)
.newObject(existingV.label())
.record(databaseProvider);
}
}
P.S. registry.system.base is in application.yml.
You need to autowire AuditRecord and not use new directly. Only that way you will have your class in Spring's context.
We don't know your exact usage of the class but you might be interested in Spring's FactoryBean.
I've a simple use-case to solve using MongoDB with Spring-data connectors.
Store a polygon or circle (simple Point with radius)
Check if give point is inside polygon/circle
Now, I've done like this:
Store give Polygon as a geoJSON into a document
Apply 2dSphere index
Polygon stored as a Polygon geoJSON type
Circle stored a single point and radius as separate parameter
Polygons I'm able to query using $geoIntersects
Circle I'm able to query using $geoNear with aggregation
Problem:
What is right way to store and index Circle(Point and radius) and Polygon (multiple points)?
How to do a single query to check if given point reside in Polygon / Circle?
currently Spring Data does not support this kind of query ($geoIntersects) using MongoRepository interface, but this works for me:
Let's suppose that we have the following document
#Document
public class AreaTown {
#Id
private String id;
private String name;
#GeoSpatialIndexed(type = GeoSpatialIndexType.GEO_2DSPHERE)
private GeoJsonPolygon area;
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public GeoJsonPolygon getArea() {
return area;
}
public void setArea(GeoJsonPolygon area) {
this.area = area;
}
#Override
public String toString() {
return "AreaTown [id=" + id + ", name=" + name + ", area=" + area + "]";
}
}
Applying a custom Query, I was able to found if a point is inside of a polygon
#SpringBootApplication
public class MongoGeoJsonApplication implements CommandLineRunner{
public static void main(String[] args) {
SpringApplication.run(MongoGeoJsonApplication.class, args);
}
#Autowired
private MongoTemplate mongoTemplate;
#Override
public void run(String... args) throws Exception {
Point inside = new Point(-97.406285,18.481136);
Query query = new Query().addCriteria(Criteria.where("area").intersects(new GeoJsonPoint(inside)));
List<AreaTown> list = mongoTemplate.find(query, AreaTown.class);
System.out.println(list);
}
}
Is it possible to use Spring's #Value annotation to read and write property values of a custom class type?
For example:
#Component
#PropertySource("classpath:/data.properties")
public class CustomerService {
#Value("${data.isWaiting:#{false}}")
private Boolean isWaiting;
// is this possible for a custom class like Customer???
// Something behind the scenes that converts Custom object to/from property file's string value via an ObjectFactory or something like that?
#Value("${data.customer:#{null}}")
private Customer customer;
...
}
EDITED SOLUTION
Here is how I did it using Spring 4.x APIs...
Created new PropertyEditorSupport class for Customer class:
public class CustomerPropertiesEditor extends PropertyEditorSupport {
// simple mapping class to convert Customer to String and vice-versa.
private CustomerMap map;
#Override
public String getAsText()
{
Customer customer = (Customer) this.getValue();
return map.transform(customer);
}
#Override
public void setAsText(String text) throws IllegalArgumentException
{
Customer customer = map.transform(text);
super.setValue(customer);
}
}
Then in application's ApplicationConfig class:
#Bean
public CustomEditorConfigurer customEditorConfigurer() {
Map<Class<?>, Class<? extends PropertyEditor>> customEditors =
new HashMap<Class<?>, Class<? extends PropertyEditor>>(1);
customEditors.put(Customer.class, CustomerPropertiesEditor.class);
CustomEditorConfigurer configurer = new CustomEditorConfigurer();
configurer.setCustomEditors(customEditors);
return configurer;
}
Cheers,
PM
You have to create a class extending PropertyEditorSupport.
public class CustomerEditor extends PropertyEditorSupport {
#Override
public void setAsText(String text) {
Customer c = new Customer();
// Parse text and set customer fields...
setValue(c);
}
}
It's possible but reading Spring documentation. You could see this example:
Example usage
#Configuration
#PropertySource("classpath:/com/myco/app.properties")
public class AppConfig {
#Autowired
Environment env;
#Bean
public TestBean testBean() {
TestBean testBean = new TestBean();
testBean.setName(env.getProperty("testbean.name"));
return testBean;
}
}
See details here
Spring can read properties and load them directly into a class.
Moreover, you can add #ConfigurationProperties(prefix = "data") on top of the class, instead of wiring each nested property one by one, by making the code cleaner.
Given all that, here is the final example with explanations:
// File: CustomerConfig.java
#Configuration
// Set property source file path (optional)
#PropertySource("classpath:/data.properties")
// Put prefix = "data" here so that Spring read properties under "data.*"
#ConfigurationProperties(prefix = "data")
public class CustomerConfig {
// Note: Property name here is the same as in the file (data.customer)
// Spring will automatically read and put "data.customer.*" properties into this object
private Customer customer;
// Other configs can be added here too... without wiring one-by-one
public setCustomer(Customer customer){
this.customer = customer;
}
public getCustomer(){
return this.customer;
}
}
That's it, now you have "data.customer.*" properties, loaded and accessible via CustomerConfig.getCustomer().
To integrate it into your service (based on your example code):
// File: CustomerService.java
#Component
#PropertySource("classpath:/data.properties")
public class CustomerService {
#Value("${data.isWaiting:#{false}}")
private Boolean isWaiting;
#Autowired // Inject configs, either with #Autowired or using constructor injection
private CustomerConfig customerConfig;
public void myMethod() {
// Now its available for use
System.out.println(customerConfig.getCustomer().toString());
}
}
This way no "magical hack" is required to read configs into a class.
Take a look at the #ConfigurationProperties documentation/examples, and this post for more useful info.
Note: I'd suggest against using PropertyEditorSupport, since
a) it was built for different purpose, may change in future by breaking the code
b) it requires manual "handling" code inside => possible bugs
Instead, use what was built right for that purpose (Spring already has it), in order to both make the code easier to understand, and to gain possible inner improvements/optimizations which might be done in the future (or present).
Further improvements: Your CustomerService seems to be cluttered with configs (#PropertyService) too. I'd suggest reading those properties via another class too (similarly) then wiring that class here, instead of doing all in the CustomerService.
If you want to use it with lists, there is a workaround using array instead.
Define your property as Customer[] instead of List then:
in ApplicationConfig class:
#Bean
public CustomEditorConfigurer customEditorConfigurer() {
Map<Class<?>, Class<? extends PropertyEditor>> customEditors =
new HashMap<Class<?>, Class<? extends PropertyEditor>>(1);
customEditors.put(Customer.class, CustomerPropertiesEditor.class);
customEditors.put(Customer[].class, CustomerPropertiesEditor.class);
CustomEditorConfigurer configurer = new CustomEditorConfigurer();
configurer.setCustomEditors(customEditors);
return configurer;
}
In CustomerEditor:
public class CustomerEditor extends PropertyEditorSupport {
public static final String DEFAULT_SEPARATOR = ",";
#Override
public void setAsText(String text) {
String[] array = StringUtils.delimitedListToStringArray(text, this.separator);
if (this.emptyArrayAsNull && array.length == 0) {
super.setValue((Object) null);
} else {
if (this.trimValues) {
array = StringUtils.trimArrayElements(array);
}
// Convert String[] to Customer[]
super.setValue(...);
}
}
}
If you want to use an existing converter/constructor, you can just call it within your expression.
For example:
#Value("#{T(org.test.CutomerMap).transform('${serialized.customer}')}")
private Customer customer;
We are using JPA Entities to get the database rows and then when we transfer that to the external, we want to use disconnected object (DTO) which are simple beans annotated with JAX-B.
We use a mapper and its code looks like this:
public BillDTO map(BillEntity source, BillDTO target) {
BeanUtils.copyProperties(source, target);
return target;
}
But when the code is running we get an error like this:
java.lang.IllegalArgumentException: argument type mismatch
Note this is the Spring implementation of the BeanUtils:
import org.springframework.beans.BeanUtils
And the naming of the properties are identical (with their getter/setter).
Anybody knows why the error happens?
And how to use a fast way instead just copying properties one by one?
This example working well. Here String property is copied to enum property:
Entity:
public class A {
private String valueFrom;
public String getValue() {
return valueFrom;
}
public void setValue(String value) {
this.valueFrom = value;
}
}
DTO (En is enumeration):
public class B {
private En valueTo;
public void setValue(String def) {
this.valueTo = En.valueOf(def);
}
public void setEnumValue(En enumVal) {
this.valueTo = enumVal;
}
}
As for your GitHub example, problem in class B in getter should be:
public String getValue()
Example:
public String getValue() {
return value.toString();
}
The Service class and my repository classes in my spring MVC set up are something like this -
public class ObjectServiceImpl implements ObjectService {
#Autowired
Temp1Repo temp1Repo;
#Autowired
Temp2Repo temp2Repo;
...
}
public interface Temp1Repo extends CrudRepository<Temp1, Integer> {
}
public interface Temp2Repo extends CrudRepository<Temp2, Integer> {
}
Now, in my service class, i am getting a object of a type Temp1, I have to call temp1Repo.save(). If I get an object of Temp2, I have to call temp2Repo.save() and so on...
How do i achieve this?
Seems fairly simple to just have an if statement:
if(object instanceof Temp1) {
temp1Repo.save((Temp1) object);
} else if(object instanceof Temp2) {
temp2Repo.save((Temp2) object);
}
Or perhaps you are looking for a more generic way?
I suppose that you want to regroup all repositories in one. Something like
#SuppressWarnings("rawtypes")
public class ObjectServiceImpl {
#Autowired
private CrudRepository[] repositories;
private Map<Class<?>, CrudRepository> repositoryMap = new HashMap<Class<?>, CrudRepository>();
#PostConstruct
public void init() {
for (CrudRepository r : repositories)
repositoryMap.put(getType(r), r);
}
private Class<?> getType(CrudRepository repository) {
Type[] types = repository.getClass().getGenericInterfaces();
for (Type t : types) {
if (t instanceof ParameterizedType)
return (Class<?>) ((ParameterizedType) t).getActualTypeArguments()[0];
}
throw new IllegalStateException("Check repositories...");
}
public void save(Object entity) {
repositoryMap.get(entity.getClass()).save(entity);
}
public <T> T get(Object id, Class<T> clazz) {
return repositoryMap.get(clazz).findOne(id);
}
....
}
Consider to use EntityManager directly, but could be useful anyway...
Following the code you wrote, Spring will rise an exception at startup time if any injection is missing.
What you want to do is a dynamic Module load, depending on a condition you omitted within your question.
You probably have to use XML configuration style and create a by condition spring context and load the correct one to be used.
Cheers