Opm plcentitymanager #29
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Ready for some review??
Ready for some review??
- updated copyrights - removed @author - fixed several small issues - added documentation
# Conflicts: # plc4j/utils/pom.xml
| @Retention(RetentionPolicy.RUNTIME) | ||
| @Target(ElementType.TYPE) | ||
| public @interface PlcEntity { | ||
| String value(); |
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maybe we can add a additional String connectionUrl() method that is semantical the same as value() but haven't found a elegant way to achieve this.
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| try (PlcConnection connection = driverManager.getConnection(source)) { | ||
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| if (!connection.getReader().isPresent()) { |
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could be replaced with orThrow()
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| // Do the necessary queries for all fields | ||
| // HashMap<ReadRequestItem<?>, Field> requestItems = new HashMap<>(); | ||
| for (Field field : clazz.getDeclaredFields()) { |
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later on we might support method injection..
| // Perform the request | ||
| PlcReadResponse<?> response; | ||
| try { | ||
| // TODO: make configurable. |
| * @return a connected entity. | ||
| * @throws OPMException when proxy can't be build. | ||
| */ | ||
| public <T> T connect(Class<T> clazz) throws OPMException { |
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confuses me a bit. Is this the same as merge in jpa?
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Its kinda similar to find(...) in JPA because it returns a connected entity.
But as it does not have a primary key (makes no sense) I decided to name it connect.
But thinking about it, it is pretty similar to merge(...) with the difference that it takes a class and not an instance.
But I'm open for changes in the naming.
| public Object intercept(@This Object o, @Origin Method m, @SuperCall Callable<?> c, @Super Object that) throws OPMException { | ||
| LOGGER.trace("Invoked method {} on connected PlcEntity {}", m.getName(), that); | ||
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| if (m.getName().startsWith("get")) { |
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maybe we should assert that no method starting with get and having attributes get picked up
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This is a fair point. And in fact, we should also support isXXX() for boolean fields.
We should add a Todo here, or better extract this in a method isGetter(m) where we can adopt all these conditions.
| PlcReader plcReader = connection.getReader().get(); | ||
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| // Build the query | ||
| PlcReadRequest.Builder builder = plcReader.readRequestBuilder(); |
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so currently only read is possible?
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Yes, perhaps I didnt state this enough. Currently, only read. It should not be that big of a deal to add writing. I'll open a Jira for that.
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Done.. is PLC4X-70
| } | ||
| } | ||
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| // TODO: why isn't o used? |
| try { | ||
| field.set(o, getTyped(field.getType(), response, fieldName)); | ||
| } catch (ClassCastException e) { | ||
| // TODO should we simply fail here? |
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think so as this can be checked beforehand and so an simple fail is sufficient here.
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In theory this should be an IllegalStateException, as this should never happen, or?
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looks good to me :) |
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Thank you @sruehl for the comments. |
I just finished the first (working) implementation of the Object-Plc-Mapping (OPM).
This is a JPA Like functionality on top of plc4x which allows to issue requests against plc4x by calling Methods on POJOs!
Basically, it uses 3 classes.
Some simple tests (with mocking) can be found in PlcEntityManagerTest.
I would be really happy for some feedback on the basic semantics (which annotations, where to put them, …) or even some testing.
If the feedback on this is positive I would like issue a PR for this.