I'm trying to implement a somewhat general converter, which transforms the data based on a given annotation. Say I want to transform these annotated strings in any matter.
All is well, until the code hits my converter's "matches" method. The "sourceType" I'm getting is always stripped out of all of the useful information. Has anyone had any success with such a setup, or am I missing something?
public class TestStringWriteConverter implements ConditionalGenericConverter {
#Override
public boolean matches(TypeDescriptor sourceType, TypeDescriptor targetType) {
if (sourceType.hasAnnotation(GivenAnnotation.class)) {
//->never gets executed, because sourceType is being stripped out of it's useful infos
}
I followed the problem to MappingMongoConverter from this package org.springframework.data.mongodb.core.convert
protected void writeInternal(Object obj, final DBObject dbo, MongoPersistentEntity<?> entity) {
//...
if (null != propertyObj) {
if (!conversions.isSimpleType(propertyObj.getClass())) {
writePropertyInternal(propertyObj, dbo, prop);
} else {
// I always end up here, which is correct but the whole prop object is being omitted in favor of the getFieldName() property
writeSimpleInternal(propertyObj, dbo, prop.getFieldName());
}
}
}
The spring versions I'm using:
<spring.version>3.2.5.RELEASE</spring.version>
<spring.data.version>1.3.2.RELEASE</spring.data.version>
Any help is much appreciated.
I think you misunderstand what sourceType.hasAnnotation(…) actually returns. As the name suggests, it inspects the type for annotations. So for a given type like this:
#MyAnnotation
class Foo { }
it would allow you to find #MyAnnotation. However you are writing about "annotated strings". I assume you mean something like:
class Bar {
#MyAnnotation
String property;
}
This is not a type annotation and the Converter API is not meant to cover such cases. If you think supporting such scenarios would be worthfile, please file a JIRA ticket.
Related
I need to dynamically assign values of cacheResolver for #Cacheable in runtime because cacheResolver has the same value for #Cacheable in every method. Hence, I use Spring AOP to dynamically assign the value but then Spring does not recognize the newly added value for cacheResolver.
Seems that AOP load #Cacheable value at the beginning.
Anyone knows how to make it work?
My AOP code:
#Aspect
#Component
#Order(1)
public class CacheableAspect {
#Pointcut("#annotation(org.springframework.cache.annotation.Cacheable)")
public void cacheablePointCut() {}
#Before("cacheablePointCut()")
public void addCacheableResolver(JoinPoint joinPoint) {
Annotation cacheableAnnotation = getCacheableAnnotation(joinPoint);
Object handler = Proxy.getInvocationHandler(cacheableAnnotation);
Field f;
try {
f = handler.getClass().getDeclaredField("memberValues");
} catch (NoSuchFieldException | SecurityException e) {
throw new IllegalStateException(e);
}
f.setAccessible(true);
Map<String, Object> memberValues;
try {
memberValues = (Map<String, Object>) f.get(handler);
} catch (IllegalArgumentException | IllegalAccessException e) {
throw new IllegalStateException(e);
}
memberValues.put("cacheResolver", "cacheableResolver");
}
private Annotation getCacheableAnnotation(JoinPoint joinPoint) {
MethodSignature signature = (MethodSignature) joinPoint.getSignature();
Method method = signature.getMethod();
return method.getAnnotation(Cacheable.class);
}
}
My #Cacheable code in which i want cacheResolver is dynamically assigned a value:
#Cacheable(value = "test")
public int test() {
System.out.println("xxx");
return 10;
}
OK, so you are trying to dynamically change an annotation representation in the JVM during runtime. Not only is that ugly, but it probably does not work as you hope it would. It seems you found out that specific annotations are represented by a dynamic proxy instance during runtime, then you are successfully manipulating one of its field values. But annotations are meant to be immutable, aber depending on when e.g. Spring scans the annotations while wiring the application, your approach to modify the proxy fields later, while being a nice try, just comes too late.
How about a more canonical approach to use multiple cache managers and/or a resolver which dynamically does what you need to begin with? As much as I love AOP, it is not the answer to everyhing.
By the way, even though your aspect is kind of useless in this case, at least we can use it as an example of how to bind annotation values to advice methods parameters, i.e. you do not need to fetch the annotation from the method by reflection next time you write an aspect:
#Pointcut("#annotation(cacheable)")
public void cacheablePointCut(Cacheable cacheable) {}
#Before("cacheablePointCut(cacheable)")
public void addCacheableResolver(JoinPoint joinPoint, Cacheable cacheable) {
Object handler = Proxy.getInvocationHandler(cacheable);
// (...)
}
I'm seeing a very bizarre issue with iBatis when trying to read a property from a Java map using isEqual, but not with other iBatis operators. For example it is able to read the map properties fine when using isNotNull and iterate. The xml:
<isNotNull property="filterCriteria.account">
AND
id
<isEqual property="filterCriteria.account.meetsCriteria" compareValue="false">
NOT
</isEqual>
IN
(SELECT DISTINCT id
FROM account
WHERE some other criteria....
)
</isNotNull>
The 2 java classes we're using here:
public class SearchProfile {
private Map<String, SearchProfileCriteria> filterCriteria;
public SAOSearchProfile() {
filterCriteria = new HashMap<>();
}
public Map<String, SAOSearchProfileCriteria> getFilterCriteria() {
return filterCriteria;
}
public void setFilterCriteria(Map<String, SAOSearchProfileCriteriaBase> filterCriteria) {
this.filterCriteria = filterCriteria;
}
}
Above is the container object that is passed to iBatis for the querying, and below is the criteria object that will be the value of the map. In this example it is keyed with the String "account"
public class SearchProfileCriteria {
boolean meetsCriteria;
public String getCriteriaAsString() {
return StringUtils.getStringValueFromBoolean(meetsCriteria);
}
public boolean isMeetsCriteria() {
return meetsCriteria;
}
public void setMeetsCriteria(boolean meetsCriteria) {
this.meetsCriteria = meetsCriteria;
}
public String getSQLString(){
return meetsCriteria ? "" : "NOT";
}
}
And the exception:
Cause: com.ibatis.common.beans.ProbeException: There is no READABLE property named 'account' in class 'java.util.Map'; nested exception is com.ibatis.common.jdbc.exception.NestedSQLException:
The getSQLString() method was my half baked attempt at a work around, the String gets escaped in the query and throws a syntax error.
When I remove the <isEqual> block the query executes find, which indicates it is able to read the "account" key when checking the to see if it is null. As I mentioned above, we're also able to use the map keys in <iterate> tags without issue. It seems <isEqual> and <isNotEqual> are the only tags causing issues. Does anyone have experience with this or know what may be going on?
Beware: Using isNotNull, isEqual, iterate is iBatis, they don't exist anymore in Mybatis, so referencing to Mybatis indifferently is confusing.
Reference documentation.
For your issue, how does it behave if replacing Map with a class (property will be known at compile time)?
Or try using <isPropertyAvailable>.
The work around could work with right syntax: $ instead of #: $filterCriteria.account.SQLString$ instead of #filterCriteria.account.SQLString#, then the value is just concatenated instead of bound as parameter.
I want to save an array of Mission.class which have variables as follows:
public class Mission {
public MissionEnum missionEnum;
public int progress;
public Mission(MissionEnum missionEnum, int progress) {
this.missionEnum = missionEnum;
this.progress = progress;
}
and also save missions in another java class:
public void saveMissions() {
Json json = new Json();
json.setOutputType(JsonWriter.OutputType.json);
json.addClassTag("Mission", Mission.class);
FileHandle missionFile = Gdx.files.local("missions_array.json");
missionFile.writeString(json.prettyPrint(missions), false);
}
and load missions:
public void loadMissions() {
if (Gdx.files.local("missions_array.json").exists()) {
try {
FileHandle file = Gdx.files.local("missions_array.json");
Json json = new Json();
json.addClassTag("Mission", Mission.class);
missions = json.fromJson(Array.class, Mission.class, file);
for (Mission mission : missions) {
Gdx.app.log(TAG, "Mission loaded: " + mission.missionEnum);
}
Gdx.app.log(TAG, "Load missions successful");
} catch (Exception e) {
Gdx.app.error(TAG, "Unable to read Missions: " + e.getMessage());
}
}
}
I got json like this:
[
{
"class": "Mission",
"missionEnum": "BUY_POWERUP"
},
{
"class": "Mission",
"missionEnum": "DISTANCE_ONE_RUN_2"
},
{
"class": "Mission",
"missionEnum": "BANANA_TOTAL_2",
"progress": 35
}
]
However when loadMissions() is run I got the "Load missions successful" log shown but "Mission loaded..." aren't shown without any error log. Missions appeared not loaded properly. I do not know what went wrong because another array is loaded successful the same way.
Not sure why there are no errors in the logs, since while reproducing your problem I've got an exception.
The problem is in loadMissions() method: you create new Json parser without setting the class tag:
Json json = new Json();
// add the line below
json.addClassTag("Mission", Mission.class);
missions = json.fromJson(Array.class, Mission.class, file);
....
Without the tag parser doesn't know what is "class": "Mission" in json file.
Update
Another thing that may cause this issue is the args-constructor. At least, when I added it I got an exception. If you don't use it - just delete.
Still, quite weird that you don't have any exceptions in logs'cos I definitely have.
Updated response:
Add an empty contructor and read this and this
You will either have to add a no-argument constructor to (Mission), or
you will have to add a custom serializer (see
https://code.google.com/p/libgdx/wiki/JsonParsing#Customizing_serialization)
that knows how to save a (Mission) instance and knows the appropriate
constructor to invoke when reading a (Mission) back in.
public Mission() {
// Do nothing.
}
Reading & writing JSON
The class implementing Json.Serializable must have a zero argument
constructor because object construction is done for you.
Alternatively delete the unused constructor. I think Enigo answer is also correct so I'm going to upvote his answer.
Providing Constructors for Your Classes
You don't have to provide any constructors for your class, but you
must be careful when doing this. The compiler automatically provides a
no-argument, default constructor for any class without constructors.
This default constructor will call the no-argument constructor of the
superclass. In this situation, the compiler will complain if the
superclass doesn't have a no-argument constructor so you must verify
that it does. If your class has no explicit superclass, then it has an
implicit superclass of Object, which does have a no-argument
constructor.
Note: I didn't test our responses, I have not developed games or used libgdx in the last two years.
Also read this libgdx issue: Json - constructor default value with Enum:
I don't know if this would be called a bug but, I have a case where I
have an enum like this;
Then I have a class with 2 constructors;
This second gets called by my framework, the first by Json
deserialization.
...
Previous response:
I guess that the missing progress field in some Mission classes can be the source of the issue but would be interesting to read the error logs to be sure.
I followed this, this and this to confirm this but it's hard without extra information about the exact log error.
I'm using app engine datastore so I have entity like this.
#PersistenceCapable
public class Author {
#PrimaryKey
#Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
#JsonProperty("id")
#JsonSerialize(using = JsonKeySerializer.class)
#JsonDeserialize(using = JsonKeyDeserializer.class)
private Key key;
....
}
When the model is sent to view, it will serialize the Key object as an Id value. Then, if I send data back from view I want to deserialize the Id back to Key object by using JsonKeyDeserializer class.
public class JsonKeyDeserializer extends JsonDeserializer<Key> {
#Override
public Key deserialize(JsonParser jsonParser, DeserializationContext deserializeContext)
throws IOException, JsonProcessingException {
String id = jsonParser.getText();
if (id.isEmpty()) {
return null;
}
// Here is the problem because I have several entities and I can't fix the Author class in this deserializer like this.
// I want to know what class is being deserialized at runtime.
// return KeyFactory.createKey(Author.class.getSimpleName(), Integer.parseInt(id))
}
}
I tried to debug the value in deserialize's parameters but I can't find the way to get the target deserialized class. How can I solve this?
You may have misunderstood the role of KeySerializer/KeyDeserializer: they are used for Java Map keys, and not as generic identifiers in database sense of term "key".
So you probably would need to use regular JsonSerializer/JsonDeserializer instead.
As to type: it is assumed that handlers are constructed for specific types, and no extra type information is passed during serialization or deserialization process: expected type (if handlers are used for different types) must be passed during construction.
When registering general serializers or deserializers, you can do this when implementing Module, as one of the arguments is type for which (de)serializer is requested.
When defining handlers directly for properties (like when using annotations), this information is available on createContextual() callback of interface ContextualSerializer (and -Deserializer), if your handler implements it: BeanProperty is passed to specify property (in this case field with annotation), and you can access its type. This information needs to be stored to be used during (de)serialization.
EDIT: as author pointed out, I actually misread the question: KeySerializer is the class name, not annotation.
Trying to implement a domain service in a SL app and getting the following error:
Parameter 'spFolderCreate' of domain method 'CreateSharePointFolder' must be an entity type exposed by the DomainService.
[EnableClientAccess()]
public class FileUploadService : DomainService
{
public void CreateSharePointFolder(SharePointFolderCreate spFolderCreate)
{
SharePointFolder spf = new SharePointFolder();
spf.CreateFolder_ClientOM(spFolderCreate.listName, spFolderCreate.fileName);
}
[OperationContract]
void CreateSharePointFolder(SharePointFolderCreate spFolderCreate);
[DataContract]
public class SharePointFolderCreate
{
private string m_listName;
private string m_fileName;
[DataMember]
public string listName
{
get { return m_listName; }
set { m_listName = value; }
}
[DataMember]
public string fileName
{
get { return m_fileName; }
set { m_fileName = value; }
}
}
So am I missing something simple here to make this all work?
It may be that the framework is inferring the intended operation because you have the word "Create" prefixing the function name (CreateSharePointFolder). Details of this behaviour can be found here
Although that is all fine for DomainServices and EntityFramework, following the information in that article, it can be inferred that methods beginning "Delete" will be performing a delete of an entity, so must accept an entity as a parameter. The same is true for "Create" or "Insert" prefixed methods. Only "Get" or "Select" methods can take non-entity parameters, making it possible to pass a numeric id (for example) to a "Get" method.
Try changing your method name temporarily to "BlahSharePointFolder" to see if it is this convention of inferrance that's causing your problem.
Also, as there is no metadata defined for your SharePointFolderCreate DC, you might need to decorate the class (in addition to the [DataContract] attribute) with the [MetadataType] attribute. You will see how to implement this if you used the DomainServiceClass wizard and point to an EF model. There is a checkbox at the bottom for generating metadata. Somewhere in your solution.Web project you should find a domainservice.metadata.cs file. In this file, you will find examples of how to use the [MetadataType] attribute.
For the RIA WCF service to work correctly with your own methods, you need to ensure that all entities existing on the parameter list have at least one member with a [Key] attribute defined in their metadata class, and that the entity is returned somewhere on your DomainService in a "Get" method.
HTH
Lee