Currently I am trying to reduce the boilerplate in my java spring controllers by creating an interface CRUDRestController, which creates a common set of default endpoints:
interface CRUDRestController<T, Key extends Serializable> {
//...
String getEndpoint();
#RequestMapping(value = getEndpoint() + "/{key}", method = RequestMethod.GET)
default T get(#PathVariable("key") String key) {
return getRepository().findOne(stringToKey(key));
}
//...
}
The problem is that the above code does not compile since value = getEndpoint() + "/{key}" is supposedly not a compile time constant. In reality every controller's implementation of getEndpoint() is something like this:
#Override
public String getEndpoint() {
return "/clients";
}
This is clearly known at compile time, however I have no way of telling this to spring. Any ideas?
Maybe that will help you:
interface CRUDRestController<T, Key extends Serializable> {
#RequestMapping(value = "/{key}", method = RequestMethod.GET)
default T get(#PathVariable("key") String key) {
return getRepository().findOne(stringToKey(key));
}
}
and the implementation:
#RequestMapping("/clients")
public class ClientController implements CRUDRestController<Client, ClientKey> {
//...
}
This is a Java annotations restriction. All values passed to it must be compile time constants.
The value is clearly not known at compile time even if you would call a static method returning a static final.
Related
I'm new to Jersey 2 and JAX-RS, so probably I'm missing something.
What I'm trying to do is a test program to define a coding style in rest services developing.
The test was written in JAVA and uses JERSEY 2.22.2, JDK 1.8.31, MOXY AS JSON Provider.
I defined a Resource with GET methods to support LIST/DETAIL. Due to the size of my POJO, I used some filters and everything was fine.
// 1) First of all I defined the annotation.
#Target({ElementType.TYPE, ElementType.METHOD, ElementType.FIELD})
#Retention(RetentionPolicy.RUNTIME)
#Documented
#EntityFiltering
public #interface MyDetailView {
public static class Factory extends AnnotationLiteral<MyDetailView>
implements MyDetailView {
private Factory() {
}
public static MyDetailView get() {
return new Factory();
}
}
// 2) Once defined the annotation, I used to
// programmaticaly exclude the list of subItems in the response...
#XmlRootElement
public class MyPojo {
...
//*** THIS SHOULD BE FILTERED IF THE ANNOTATION IS NOT SPECIFIED IN THE RESPONSE ***
#MyDetailView
private List<SubItem> subItems = new ArrayList<SubItem>();
public List<SubItem> getSubItems() {
return subItems;
}
public void setSubItems(List<SubItem> subItems) {
this.subItems = subItems;
}
}
// 3) I registered the EntityFilteringFeature
public class ApplicationConfig extends ResourceConfig {
public ApplicationConfig() {
....
register(EntityFilteringFeature.class);
}
// 4) Finally, I wrote the code to include/exclude the subItems
/*
The Resource class has getCollection() and getItem() methods...
getCollection() adds the annotation only if filterStyle="detail"
getItem() always add the annotation
*/
#Path(....)
#Produces(MediaType.APPLICATION_JSON)
#Consumes(MediaType.APPLICATION_JSON)
public class MyResource extends SecuredResource {
//filterStyle -> "detail" means MyDetailAnnotation
#GET
public Response getCollection(
#QueryParam("filterStyle") String filterStyle,
#Context UriInfo uriInfo) {
//THIS CODE AFFECTS THE RESPONSE
boolean detailedResponse = "detail".equals(filterStyle);
Annotation[] responseAnnotations = detailedResponse
? new Annotation[0]
: new Annotation[]{MyDetailView.Factory.get()};
//pojo collection...
MyPagedCollection myCollection = new MyPagedCollection();
//.....
ResponseBuilder builder = Response.ok();
return builder.entity(myCollection, responseAnnotations).build();
}
#GET
#Path("/{id}")
public Response getItem(#PathParam("{id}") String idS, #Context UriInfo uriInfo) {
MyPOJO pojo = ...
Annotation[] responseAnnotations = new Annotation[]{MyDetailView.Factory.get()};
return Response.ok().entity(pojo, responseAnnotations).build();
}
}
After the first test, I tried to use the SelectableEntityFilteringFeature to allow the client to ask for specific fields in the detail, so I changed the ApplicationConfig
public class ApplicationConfig extends ResourceConfig {
public ApplicationConfig() {
....
register(EntityFilteringFeature.class);
register(SelectableEntityFilteringFeature.class);
property(SelectableEntityFilteringFeature.QUERY_PARAM_NAME, "fields");
}
and I've add the "fields" QueryParam to the Resource getItem() method...
#GET
#Path("/{id}")
public Response getDetail(#PathParam({id}) String id,
#QueryParam("fields") String fields,
#Context UriInfo uriInfo) {
....
But as long as I registered the SelectableEntityFilteringFeature class, the EntityFilteringFeature class stopped working. I tried to add "fields" parameter to one of the Resource methods, it worked perfectly. But the MyDetailAnnotation was completely useless.
I tried to register it using a DynamicFeature
public class MyDynamicFeature implements DynamicFeature {
#Override
public void configure(ResourceInfo resourceInfo, FeatureContext context) {
if ("MyResource".equals(resourceInfo.getResourceClass().getSimpleName())
&& "getItem".equals(resourceInfo.getResourceMethod().getName())) {
//*** IS THE CORRECT WAY TO BIND A FEATURE TO A METHOD? ***
//
context.register(SelectableEntityFilteringFeature.class);
context.property(SelectableEntityFilteringFeature.QUERY_PARAM_NAME, "fields");
}
}
Now the questions:
1) Why registering both the SelectableEntityFilteringFeature feature breaks the EntityFilteringFeature?
2) What is the correct way to bind a feature to a method with the DynamicFeature interface?
Thanks in advance.
This is my first post to Stack Overflow, I hope it was written complaining the rules.
Short answer: you can't. It appears to be a bug as of 2.25.1 and up to 2.26(that I tested with). https://github.com/jersey/jersey/issues/3523
SelectableEntityFilteringFeature implictily registers EntityFilteringFeature (As mentioned here). So I don't see a need to add this.
Since you need Annotation based filtering, you can exclude registering SelectableEntityFilteringFeature.
You can just do,
// Set entity-filtering scope via configuration.
.property(EntityFilteringFeature.ENTITY_FILTERING_SCOPE, new Annotation[] {MyDetailView.Factory.get()})
// Register the EntityFilteringFeature.
.register(EntityFilteringFeature.class)
// Further configuration of ResourceConfig.
You can refer to this example for usage and this example for registering the filter.
So you can remove SelectableEntityFilteringFeature and try just the above mentioned way to register it.
I want to convert Optional<BigDecimal> in morphia. I created BigDecimalConverter, and it works fine. Now I want to create OptionalConverter.
Optional can hold any object type. In my OptionalConverter.encode method I can extract underlying object, and I'd like to pass it to default mongo conversion. So that if there is string, I'll just get string, if there is one of my entities, I'll get encoded entity. How can I do it?
There are two questions:
1. How to call other converters?
2. How to create a converter for a generic class whose type parameters are not statically known?
The first one is possible by creating the MappingMongoConveter and the custom converter together:
#Configuration
public class CustomConfig extends AbstractMongoConfiguration {
#Override
protected String getDatabaseName() {
// ...
}
#Override
#Bean
public Mongo mongo() throws Exception {
// ...
}
#Override
#Bean
public MappingMongoConverter mappingMongoConverter() throws Exception {
MappingMongoConverter mmc = new MappingMongoConverter(
mongoDbFactory(), mongoMappingContext());
mmc.setCustomConversions(new CustomConversions(CustomConverters
.create(mmc)));
return mmc;
}
}
public class FooConverter implements Converter<Foo, DBObject> {
private MappingMongoConverter mmc;
public FooConverter(MappingMongoConverter mmc) {
this.mmc = mmc;
}
public DBObject convert(Foo foo) {
// ...
}
}
public class CustomConverters {
public static List<?> create(MappingMongoConverter mmc) {
List<?> list = new ArrayList<>();
list.add(new FooConverter(mmc));
return list;
}
}
The second one is much more difficult due to type erasure. I've tried to create a converter for Scala's Map but haven't found a way. Unable to get the exact type information for the source Map when writing, or for the target Map when reading.
For very simple cases, e.g. if you don't need to handle all possible parameter types, and there is no ambiguity while reading, it may be possible though.
I am creating a custom tag library using http://www.cqblueprints.com/xwiki/bin/view/Blue+Prints/Writing+A+JSP+Custom+Tag+Library to produce XSS-proof links from my custom components. I have taken this to a tag since I will need to do other bits of work and to avoid writing scriptlets on the JSP files (I have posted the code at the end).
I wanted to use the XSSAPI from my Java class, but looking at the javadoc for XSSAPI I see that it's an interface; when using it in a JSP file it's an object that is initialized invoking <cq:defineObjects/>.
Does anyone have any ideas on how to do this? There is a method in the XSSAPI class called getRequestSpecificAPI(slingRequest) but it's not static, and I have run out of ideas right now.
#JspTag
public class FixInternalLinkTag extends CqSimpleTagSupport {
private String pathToPage;
#Override
public void doTag() throws JspException, IOException {
XSSAPI xssAPI; // ToDo how to get a reference to this?
urlPointingToPage = xssAPI.getValidHref(urlPointingToPage);
getJspWriter().write(urlPointingToPage);
}
public String getPathToPage() {
return pathToPage;
}
#JspTagAttribute(required = true, rtexprvalue = true)
public void setPathToPage(String pathToPage) {
this.pathToPage = pathToPage;
}
}
If you make your tag class an osgi service
#Component(immediate = true, metatype = true, description = "User Group Finder")
#Service
public class MyClass { ...
you can then use
#Reference
XSSAPI xssapi;
to pull in the implementation of XSSAPI. Then you can use it
xssapi.getRequestSpecificAPI(slingRequest);
I have the following class:
public class MyClass {
#Inject
private MyAnotherClass myAnotherClass;
public MyClass() {
//Perform operations on myAnotherClass.
}
}
I need to do some things in constructor which require an instance of myAnotherClass. Unfortunately myAnotherClass is injected after code in constructor is ran, which means I am performing operations on null...
I could of course instantiate it the classic way (MyAnotherClass myAnotherClass = new MyAnotherClass()) directly in constructor, but I don't think it is the right thing to do in this situation.
What solutions would you suggest to solve this problem?
Best option:
public class MyClass {
private final MyAnotherClass myAnotherClass;
public MyClass(MyAnotherClass other) {
this.myAnotherClass = other;
// And so forth
}
}
T5-IoC will then use constructor injection so there's no need to 'new' up MyClass yourself. See Defining Tapestry IOC Services for more info.
Alternatively:
public class MyClass {
#Inject
private MyAnotherClass myAnotherClass;
#PostInjection
public void setupUsingOther() {
// Called last, after fields are injected
}
}
Since version 1.4.2 of XStream, the XStreamConverter annotation takes additional parameters (very good feature and just what I need).
#XStreamConverter(value=CustomXStreamConverter.class, strings={xyz"})
private List<String> phones;
But how can I read this values (xyz) in my custom converter?
public class CustomXStreamConverter implements Converter {
//?
}
I figure out the solution, just override the class constructor in order to receive the parameter.
public class CustomXStreamConverter implements Converter {
private String alias;
public ListToStringXStreamConverter(String alias) {
super();
this.alias = alias; //xyz
}
//...