{"id":348,"date":"2009-06-11T20:18:00","date_gmt":"2009-06-11T20:18:00","guid":{"rendered":"http:\/\/www.tutego.de\/blog\/javainsel\/?p=348"},"modified":"2009-06-11T20:18:00","modified_gmt":"2009-06-11T20:18:00","slug":"jaque-version-1-5-ms-linq-expression-trees-fur-java","status":"publish","type":"post","link":"https:\/\/www.tutego.de\/blog\/javainsel\/2009\/06\/jaque-version-1-5-ms-linq-expression-trees-fur-java\/","title":{"rendered":"JaQue Version 1.5: MS LINQ Expression Trees f\u00fcr Java"},"content":{"rendered":"

Von der Webseite<\/a>:<\/p>\n

\n

JaQue provides an infrastructure for Microsoft <\/a>LINQ<\/a> like capabilities on Java platform. Using ASM<\/a>, JaQue builds expression trees, which are used to build a query in domain specific technology or language, such as SQL. This way Java developers can focus on writing application logic in the language they know – Java, regardless what the underlying technology or language is in use. JaQue to Objects and JaQue to XML are currently supported and JaQue to JPA is under development.<\/p>\n<\/blockquote>\n

Ein Beispiel macht das praktisch deutlich:<\/p>\n

EntityManagerFactory emf = Persistence.createEntityManagerFactory(\"hibernate\");
  EntityManager em = emf.createEntityManager();
  JaqueEntityManager jem = new JaqueEntityManager(em);
  Queryable<Order> orders = jem.from(Order.class);

  System.out.println(count(where(new Predicate<Order>() {
        public Boolean invoke(Order t) throws Throwable {
                return t.getOrderID() > 11000;
        }
  }, orders)));<\/pre>\n
<\/p>\n
Wie bei LINQ soll eine eine API f\u00fcr die verschiedenen Datenquellen geben, also XML, Objekte, Datenbanken, \u2026 F\u00fcr JPA schreibt die Seite \u201cCurrently it’s able to perform only simple SELECTs, JOINs and AGGREGATEs\u201d. Das ist nat\u00fcrlich nicht viel. Insofern ist diese L\u00f6sung WEIT von den LINQ to SQL-M\u00f6glichkeiten entfernt.<\/p>\n
<\/p>\n
Der Hinweis der Webseite auf \u201cInteroperability with Java Closures<\/a>\u201d ist nat\u00fcrlich hinf\u00e4llig. Dadurch, dass Closures aber wegfallen, wird die ganze API viel aufgebl\u00e4hter, als wenn man Closures h\u00e4tte. Die Scala-Variante ist daher auch viel k\u00fcrzer.<\/p>\n
<\/p>\n
 <\/p>\n
<\/p>\n
PS: Die n\u00e4chsten 2 Wochen gibt es keine Blog-Eintr\u00e4ge, da ich ich Afrika bin.<\/p>\n","protected":false},"excerpt":{"rendered":"
Von der Webseite: JaQue provides an infrastructure for Microsoft LINQ like capabilities on Java platform. Using ASM, JaQue builds expression trees, which are used to build a query in domain specific technology or language, such as SQL. This way Java developers can focus on writing application logic in the language they know – Java, regardless […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[4],"tags":[],"class_list":["post-348","post","type-post","status-publish","format-standard","hentry","category-open-source"],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.tutego.de\/blog\/javainsel\/wp-json\/wp\/v2\/posts\/348","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.tutego.de\/blog\/javainsel\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.tutego.de\/blog\/javainsel\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.tutego.de\/blog\/javainsel\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.tutego.de\/blog\/javainsel\/wp-json\/wp\/v2\/comments?post=348"}],"version-history":[{"count":0,"href":"https:\/\/www.tutego.de\/blog\/javainsel\/wp-json\/wp\/v2\/posts\/348\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.tutego.de\/blog\/javainsel\/wp-json\/wp\/v2\/media?parent=348"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.tutego.de\/blog\/javainsel\/wp-json\/wp\/v2\/categories?post=348"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.tutego.de\/blog\/javainsel\/wp-json\/wp\/v2\/tags?post=348"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}