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Practical Module Examples in Software Creation ECC200 in Software Practical Module Examples




How to generate, print barcode using .NET, Java sdk library control with example project source code free download:
Practical Module Examples using software tointegrate data matrix barcode in asp.net web,windows application Java } public Qu Data Matrix barcode for None ery start(int start) { query.setStart(start); return this; } public List<String> fetchIds() { query.setFields("id"); SolrDocumentList results = getResponse(); List<String> ids = new ArrayList(results.

size()); for (SolrDocument doc : results) { String entityId = doc.getFieldValue("id").toString().

split(":")[1]; ids.add(entityId); } return ids; } public <T extends Model> List<T> fetch() { List<T> result = new ArrayList<T>(); List<String> ids = fetchIds(); for (String id : ids) { Object objectId = getIdValueFromIndex(clazz, id); result.add((T) JPA.

em().find(clazz, objectId)); } return result; } private SolrDocumentList getResponse() { try { QueryResponse rp = server.query(query); return rp.

getResults(); } catch (SolrServerException e) { Logger.error(e, "Error on solr query: %s", e.getMessage()); } return new SolrDocumentList(); }.

6 private Object getIdValueFromIndex(Class< > clazz, String indexValue) { java.lang.reflect.

Field field = getIdField(clazz); Class< > parameter = field.getType(); try { return Binder.directBind(indexValue, parameter); } catch (Exception e) { throw new UnexpectedException("Could not convert the ID from index to corresponding type", e); } } private java.

lang.reflect.Field getIdField(Class< > clazz) { for (java.

lang.reflect.Field field : clazz.

getFields()) { if (field.getAnnotation(Id.class) != null) { return field; } } throw new RuntimeException("Your class " + clazz.

getName() + " is annotated with javax.persistence.Id but the field Id was not found"); } }.

This class Data Matrix 2d barcode for None issues the query, gets the result, and performs database lookups for the returned IDs, if necessary. The plugin class which invokes the bytecode enhancer on startup is the central piece of the following plugin:. public clas s SolrPlugin extends PlayPlugin { private SolrEnhancer enhancer = new SolrEnhancer(); public void enhance(ApplicationClass applicationClass) throws Exception { enhancer.enhanceThisClass(applicationClass); } public void onEvent(String message, Object context) { if (!StringUtils.startsWith(message, "JPASupport.

")) { return; } try {. Practical Module Examples Model model = (Model) context; String entityId = model.getClass().getName() + ":" + model.

getId().toString(); SolrServer server = getSearchServer(); server.deleteById(entityId); if ("JPASupport.

objectUpdated".equals(message)) { SolrInputDocument doc = new SolrInputDocument(); doc.addField("id", entityId); doc.

addField("searchClass", model.getClass().getName()); for (java.

lang.reflect.Field field : context.

getClass(). getFields()) { String fieldName = field.getName(); Field annot = field.

getAnnotation(Field.class); if (annot == null) { continue; } String annotationValue = annot.value(); if (annotationValue != null && !"#default".

equals(annotationValue)) { fieldName = annotationValue; } doc.addField(fieldName, field.get(context)); } server.

add(doc); } server.commit(); } catch (Exception e) { Logger.error(e, "Problem updating entity %s on event %s with error %s", context, message, e.

getMessage()); } } public static SolrServer getSearchServer() { String url = Play.configuration.getProperty("solr.

server", "http://localhost:8983/solr"); CommonsHttpSolrServer server = null; try { server = new CommonsHttpSolrServer( url ); server.setRequestWriter(new BinaryRequestWriter()); } catch (MalformedURLException e) {. 6 Logger.e Software Data Matrix ECC200 rror(e, "Problem creating solr server object: %s", e.getMessage()); } return server; } }.

The last st ep is to configure your entities inside your application appropriately like the following User entity:. package mod Software ECC200 els; import javax.persistence.Entity; import org.

apache.solr.client.

solrj.beans.Field import play.

modules.solr.SearchModel; @Entity public class User extends SearchModel { @Field public String name; @Field public String shortDescription; @Field("tw_s") public String twitter; public Car car; }.

As you can see, you can annotate your fields to be indexed with the @Field annotation from the solrj client. As SolrJ is also used when indexing the entities the plugin does not have to define its own annotations..

How it works... A lot of so urce code is needed, for a lot of functionality. There are many pieces needing an explanation. First, a little bit of information about how Solr querying works.

The plugin does not use XML to import data into Solr, but rather binary data, as it is way faster than creating an XML response and sending it to the server. You explicitly have to configure Solr to support this binary format, which is described in the SolrJ wiki page at http://wiki.apache.

org/ solr/Solrj.. Practical M Software barcode data matrix odule Examples Furthermore, SolrJ supports indexing beans directly instead of creating a SolrInputDocument out of it. This does work for entities, as they are complex objects with more than simple types. The problem is the entity ID field.

This field is included in the model class, where it also would need to be annotated. However, this would mean that there could be only one class stored, as entity IDs are similar on different models. So the creation of the ID has to be performed manually.

The adding of entities to the index is again done via the event mechanism of Play. Whenever an entity is updated or deleted it is propagated to the index. This is done in the SolrPlugin.

When you take a look at the onEvent() method, you will see that when the right event occurs the following happens: f The old document gets deleted from the index f A new document is created, with the ID of the entity f A searchClass property is added, which is needed for querying entities of a certain type f Every field of an entity with a @Field annotation is added to the document, possibly under a different name than the name of the field in the entity, if specified in the annotation Be aware that you cannot store object graphs with Solr. This is basically all the code needed to store data into Solr. The SearchModel class serves two purposes.

First, it enables you to have IDE support and auto completion for the static search() method, second it translates the already known find("byFooAndBar") syntax to a real search query. The last part is the Query class, which issues actual search queries and parses the results. Similar to the JPAQuery, which is returned when calling the find() method of an entity, it features a limit on the result size as well as starting from an offset.

It also features the fetch() method. This method fetches all the IDs from the Solr search and then queries the database to get the complete entity. Be aware that this again adds some load to your database.

The fetchIds() method returns the IDs from the search, but will not query your database. Until now it has looked like as if it was not necessary at all to configure Apache Solr. This is not completely true.

When you take a look at your schema.xml file, you will find the case of defining a schema for indexing and the support for dynamic fields. Dynamic fields often end with "_s" to represent a dynamic string field.

This is used in the User entity above for the Twitter handle. However, as the name and shortDescription fields of this entity do not have such an alias set, they have to be defined like this:. <field n ame="name" type="string" indexed="true" stored="true"/> <field name="shortDescription" type="text" indexed="true" stored="true"/> <field name="searchClass" type="textgen" indexed="true" stored="true" required="true" /> <field name="id" type="string" indexed="true" stored="true" required="true" />.
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