Spring Data - SpelEvaluationException - Property or field cannot be found on null - spring

I'm trying to use Spring Expression Language to configure an annotation from Spring Data ElasticSearch dynamically. The solutions I tried (this and this) produce the following error in my case:
Caused by: SpelEvaluationException: EL1007E: Property or field
'DbCreatorIndexNameConfig' cannot be found on null
The annotation in question is:
#ComponentScan(basePackageClasses = DbCreatorIndexNameConfig.class)
#Document(indexName = "#{DbCreatorIndexNameConfig.indexName()}", type = "video",
shards = 1, replicas = 0)
public class Video implements EsModel {
//...
The bean in question:
#Configuration("DbCreatorIndexNameConfig")
#ComponentScan(basePackageClasses = Video.class)
public class DbCreatorIndexNameConfig {
#Value("video_default")
public String indexName;
#Bean
public String indexName() {
return indexName;
}
public void setIndexName(String indexName) {
this.indexName = indexName;
}
}
Notes:
I have made sure, that the bean is wired into the application context via new AnnotationConfigApplicationContext(EsSpringTemplate.class, DbCreatorIndexNameConfig.class);
I have made sure that Spring knows the needed beans. They appear in
annotationConfigApplicationContext.getBeanDefinitionNames().
indexName must be a constant. Therefor it seems only possible to use SpEL
Any idea is highly appreciated! Thanks!

Modify it as follows:- You have to use '#' to access a bean in spel
#Document(indexName = "#{#DbCreatorIndexNameConfig.indexName()}", type = "video",
shards = 1, replicas = 0)

Related

Spring #Value not working in Spring Boot 2.5.5, getting null values

I am trying to inject some property values into variables by means of Spring #Value annotation but I get null values. I tried different configurations and triks but it doesn't work. Think is that before today everythink was working properly. I do not know what I changed in order to get things broken.
Here is my java class:
#Component
#ConditionalOnProperty(prefix = "studioghibli", name = "get")
public class StudioGhibliRestService {
#Value("${studioghibli.basepath}")
private static String BASE_PATH;
#Value("${studioghibli.path}")
private static String PATH;
#Value("${studioghibli.protocol:http}")
private static String PROTOCOL;
#Value("${studioghibli.host}")
private static String HOST;
private static String BASE_URI = PROTOCOL.concat("://").concat(HOST).concat(BASE_PATH).concat(PATH);
#Autowired
StudioGhibliRestConnector connector;
public List<StudioGhibliFilmDTO> findAllFilms() throws SipadContenziosoInternalException {
var response = connector.doGet(BASE_URI, null, null);
if (!response.getStatusCode().is2xxSuccessful() || !response.hasBody()) {
throw new SipadContenziosoInternalException(Errore.INTERNAL_REST_ERROR, "FindAll(), microservizio ".concat(BASE_URI), null);
}
return (List<StudioGhibliFilmDTO>) response.getBody();
}
}
As you can see, the class is annotated with #Component, that because I will need to use it as #Service layer in order to make a rest call in my business logic.
The class is also annotaded with conditional on property...
Here is a screenshot of the debug window at startup:
Since the PROTOCOL value is null, i get a null pointer exception immediately at start up.
Here is part of the application-dev.properties file:
studioghibli.get
studioghibli.protocol=https
studioghibli.host=ghibliapi.herokuapp.com
studioghibli.basepath=/
studioghibli.path=/films
First of all, #Value annotation does not work with static fields.
Secondly, fields with #Value annotation is processed when the instance of the class (a bean) is created by Spring, but static fields exist for a class (for any instance), so when the compiler is trying to define your static BASE_URI field other fields are not defined yet, so you get the NPE on startup.
So you might need a refactoring, try to inject values with the constructor like this:
#Component
#ConditionalOnProperty(prefix = "studioghibli", name = "get")
public class StudioGhibliRestService {
private final StudioGhibliRestConnector connector;
private final String baseUri;
public StudioGhibliRestService(StudioGhibliRestConnector connector,
#Value("${studioghibli.basepath}") String basePath,
#Value("${studioghibli.path}") String path,
#Value("${studioghibli.protocol:http}") String protocol,
#Value("${studioghibli.host}") String host) {
this.connector = connector;
this.baseUri = protocol.concat("://").concat(host).concat(basePath).concat(path);
}
// other code
}
Thanks, It works for me, I have to add some codes to my project. Then I check the spring core document in "#Value" section. Besides
When configuring a PropertySourcesPlaceholderConfigurer using
JavaConfig, the #Bean method must be static.
#Bean
public static PropertySourcesPlaceholderConfigurer propertyPlaceholderConfigurer(){
return new PropertySourcesPlaceholderConfigurer();
}

Evaluate property from properties file in Spring's #EventListener(condition = "...")

I would like to make the execution of an event handler dependent on whether or not a property is set to true in a properties file.
#EventListener(ContextRefreshedEvent.class, condition = "${service.enabled}")
public void onStartup() { }
However, this does not seem to work. I am getting the following error on startup:
org.springframework.expression.spel.SpelParseException: EL1043E:(pos 1): Unexpected token. Expected 'identifier' but was 'lcurly({)'
Is it possible to use a property from a properties file as a condition here?
The issue is condition argument is expecting a SPEL.
This works try it out.
In your bean where you have this #EventListener, add these lines
public boolean isServiceEnabled() {
return serviceEnabled;
}
#Value("${service.enabled}")
public boolean serviceEnabled;
change your declaration of evnt listener like this
#EventListener(classes = ContextRefreshedEvent.class, condition = "#yourbeanname.isServiceEnabled()")
public void onStartup() { }
change yourbeanname with the correct bean name .
I had the same annoying experience (with Spring Boot 2.4.2 on Java11).
In my case I had the boolean property in a #ConfigurationProperties class anyways in the same java file and still struggled a bit. First the #ConfigurationProperties need to be annotated as #Component to actually be a valid Bean and can be used in SpEL.
And I had to use the same long attributeName for the ConfigurationProperties in the Service itself and the EventListener Annotation for the Bean resolution to work fine. I needed some the ConfigurationProperties values also in another place of the Service, that's why they needed to be (Constructor) Autowired as well...
So this worked for me:
#ConfigurationProperties("my.custom.path")
#Component //Important to make this a proper Spring Bean
#Data //Lombok magic for getters/setters etc.
class MyCustomConfigurationProperties {
boolean refreshAfterStartup = true;
}
#Service
#RequiredArgsConstructor //Lombok for the constructor
#EnableConfigurationProperties(MyCustomConfigurationProperties.class)
#EnableScheduling
public class MyCustomService {
private final MyCustomConfigurationProperties myCustomConfigurationProperties;
#EventListener(value = ApplicationReadyEvent.class, condition = "#myCustomConfigurationProperties.refreshAfterStartup")
public void refresh() {
//the actual code I want to execute on startup conditionally
}
}

Inject properties name into class anotation

Is it possible to inject property name into the procedureName?
im using spring boot.
Try to use the next the next construction:
procedureName = "${procedure}" but it doesnt work
Also to write the special PropertySourcesPlaceholderConfigurer i think it not a good idea .
#NamedStoredProcedureQueries({
#NamedStoredProcedureQuery(name = "test",
procedureName = "${procedure}",
parameters = {
})
})
public class R
try to get property from properties-test.yml
Spring properties used to inject values in bean properties like below,
public class ClassWithInjectedProperty {
#Value("${props.foo}")
private String foo;
}
you case is not valid for value injection.

spring data elasticsearch inheritence no results on query

I have some trouble with inheritence and ElasticsearchRepository.
My code (short version) :
Entities :
public abstract class father{
#Id
protected String identifier;
// constructors
#Field(type= FieldType.String, index = FieldIndex.not_analyzed)
public String uri;
// getter setter
}
/*
* Stored in elastic search
*/
#Document(indexName = "entity1", type = "entity1")
public abstract class sonA extends father{
// constructors
}
/*
* Stored in elastic search
*/
#Document(indexName = "entity2", type = "entity2")
public abstract class sonB extends father{
// constructors
}
Repository :
public interface DataBnfRepository extends
ElasticsearchRepository<SonA, String> {
public SonA findByUri(String uri);
#Query("{ \"filtered\":{ \"filter\":{\"term\":{\"uri\":\"?0\"}}}}")
public SonA findWithUri(String uri);
}
My trouble : I'm able to put data into elastic search but not to retreive them.
If I do a repository.findall() it works.
If I do a repository.findWithUri(uri) it does not work (null result)
Parse exception for findByUri
I tried to search for exemples :
https://github.com/spring-projects/spring-data-elasticsearch/blob/master/src/test/java/org/springframework/data/elasticsearch/entities/SampleInheritedEntity.java
But there's no repository.
What I have found: If i replace the uri by"foo", it works. So the problem is with https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-query-string-query.html#_reserved_characters
So i made a test with
uri = foo:bar => parse exception.
uri = "foo:bar" => parse exception.
uri = foo\:bar => parse exception.
uri = "foo\:bar" => parse exception
Before it was inherited I had no problems with the code.
I just put the URI in an object, repository.save(object) and repository.findWithUri(uri), it give me the object.
Any help/suggestion/comments is greatly appreciated. Please. Thank you so much
Try the following method.
findByFatherUri(uri);
This is how it works for Child Entities. I think it's the same for Extended Classes as well. From Spring Data's point of view, main class is SonA for DataBnfRepository and it's id is the one linked to the Repository when you use findOne method. You have to traverse through the child class to the field you are trying use to find the object. Since, I am not sure 100%, let me know if this works once you tried.

Spring Boot equivalent to XML multi-database configuration

I would like to port two projects to Spring Boot 1.1.6. The are each part of a larger project. They both need to make SQL connections to 1 of 7 production databases per web request based region. One of them persists configuration setting to a Mongo database. They are both functional at the moment but the SQL configuration is XML based and the Mongo is application.properties based. I'd like to move to either xml or annotation before release to simplify maintenance.
This is my first try at this forum, I may need some guidance in that arena as well. I put the multi-database tag on there. Most of those deal with two connections open at a time. Only one here and only the URL changes. Schema and the rest are the same.
In XML Fashion ...
#Controller
public class CommonController {
private CommonService CommonService_i;
#RequestMapping(value = "/rest/Practice/{enterprise_id}", method = RequestMethod.GET)
public #ResponseBody List<Map<String, Object>> getPracticeList(#PathVariable("enterprise_id") String enterprise_id){
CommonService_i = new CommonService(enterprise_id);
return CommonService_i.getPracticeList();
}
#Service
public class CommonService {
private ApplicationContext ctx = null;
private JdbcTemplate template = null;
private DataSource datasource = null;
private SimpleJdbcCall jdbcCall = null;
public CommonService(String enterprise_id) {
ctx = new ClassPathXmlApplicationContext("database-beans.xml");
datasource = ctx.getBean(enterprise_id, DataSource.class);
template = new JdbcTemplate(datasource);
}
Each time a request is made, a new instance of the required service is created with the appropriate database connection.
In the spring boot world, I've come across one article that extended TomcatDataSourceConfiguration.
http://xantorohara.blogspot.com/2013/11/spring-boot-jdbc-with-multiple.html That at least allowed me to create a java configuration class however, I cannot come up with a way to change the prefix for the ConfigurationProperties per request like I am doing with the XML above. I can set up multiple configuration classes but the #Qualifier("00002") in the DAO has to be a static value. //The value for annotation attribute Qualifier.value must be a constant expression
#Configuration
#ConfigurationProperties(prefix = "Region1")
public class DbConfigR1 extends TomcatDataSourceConfiguration {
#Bean(name = "dsRegion1")
public DataSource dataSource() {
return super.dataSource();
}
#Bean(name = "00001")
public JdbcTemplate jdbcTemplate(DataSource dsRegion1) {
return new JdbcTemplate(dsRegion1);
}
}
On the Mongo side, I am able to define variables in the configurationProperties class and, if there is a matching entry in the appropriate application.properties file, it overwrites it with the value in the file. If not, it uses the value in the code. That does not work for the JDBC side. If you define a variable in your config classes, that value is what is used. (yeah.. I know it says mondoUrl)
#ConfigurationProperties(prefix = "spring.mongo")
public class MongoConnectionProperties {
private String mondoURL = "localhost";
public String getMondoURL() {
return mondoURL;
}
public void setMondoURL(String mondoURL) {
this.mondoURL = mondoURL;
}
There was a question anwsered today that got me a little closer. Spring Boot application.properties value not populating The answer showed me how to at least get #Value to function. With that, I can set up a dbConfigProperties class that grabs the #Value. The only issue is that the value grabbed by #Value is only available in when the program first starts. I'm not certain how to use that other than seeing it in the console log when the program starts. What I do know now is that, at some point, in the #Autowired of the dbConfigProperties class, it does return the appropriate value. By the time I want to use it though, it is returning ${spring.datasource.url} instead of the value.
Ok... someone please tell me that #Value is not my only choice. I put the following code in my controller. I'm able to reliably retrieve one value, Yay. I suppose I could hard code each possible property name from my properties file in an argument for this function and populate a class. I'm clearly doing something wrong.
private String url;
//private String propname = "${spring.datasource.url}"; //can't use this
#Value("${spring.datasource.url}")
public void setUrl( String val) {
this.url = val;
System.out.println("==== value ==== " + url);
}
This was awesome... finally some progress. I believe I am giving up on changing ConfigurationProperties and using #Value for that matter. With this guy's answer, I can access the beans created at startup. Y'all were probably wondering why I didn't in the first place... still learning. I'm bumping him up. That saved my bacon. https://stackoverflow.com/a/24595685/4028704
The plan now is to create a JdbcTemplate producing bean for each of the regions like this:
#Configuration
#ConfigurationProperties(prefix = "Region1")
public class DbConfigR1 extends TomcatDataSourceConfiguration {
#Bean(name = "dsRegion1")
public DataSource dataSource() {
return super.dataSource();
}
#Bean(name = "00001")
public JdbcTemplate jdbcTemplate(DataSource dsRegion1) {
return new JdbcTemplate(dsRegion1);
}
}
When I call my service, I'll use something like this:
public AccessBeans(ServletRequest request, String enterprise_id) {
ctx = RequestContextUtils.getWebApplicationContext(request);
template = ctx.getBean(enterprise_id, JdbcTemplate.class);
}
Still open to better ways or insight into foreseeable issues, etc but this way seems to be about equivalent to my current XML based ways. Thoughts?

Resources