{"id":255,"date":"2007-11-16T16:39:16","date_gmt":"2007-11-16T21:39:16","guid":{"rendered":"http:\/\/www.khaitan.org\/blog\/archives\/188"},"modified":"2007-11-16T16:39:16","modified_gmt":"2007-11-16T21:39:16","slug":"java-generics-taking-the-fun-away-from-writing-code-in-java","status":"publish","type":"post","link":"https:\/\/www.khaitan.org\/blog\/2007\/11\/java-generics-taking-the-fun-away-from-writing-code-in-java\/","title":{"rendered":"Java Generics: Taking the fun away from writing code in Java"},"content":{"rendered":"

Coding in Java was simple until Java 5 (or Java 1.5 — 1.5 is the developer version and Java 5 is the marketing version as Sun calls<\/a> it!). Learning generics<\/a> in Java 1.5 is like learning Microsoft COM programming, it would take at least 5 passes to absorb it right.<\/p>\n

Look at this simple call, before generics<\/p>\n

\n1<\/a> List<\/font> myIntList<\/font> =<\/font> new<\/strong> LinkedList<\/font>(<\/strong><\/font>)<\/strong><\/font>;<\/font> <\/font>\n2<\/a> myIntList<\/font>.add<\/font>(<\/strong><\/font>new<\/strong> Integer<\/font>(<\/strong><\/font>0<\/font>)<\/strong><\/font>)<\/strong><\/font>;<\/font> <\/font>\n3<\/a> Integer<\/font> x<\/font> =<\/font> (<\/strong><\/font>Integer<\/font>)<\/strong><\/font> myIntList<\/font>.iterator<\/font>(<\/strong><\/font>)<\/strong><\/font>.next<\/font>(<\/strong><\/font>)<\/strong><\/font>;<\/font> <\/font>\n<\/pre>\n
How about now:<\/p>\n
\n1<\/a> List<\/font><<\/font>Integer<\/font>><\/font> myIntList<\/font> =<\/font> new<\/strong> LinkedList<\/font><<\/font>Integer<\/font>><\/font>(<\/strong><\/font>)<\/strong><\/font>;<\/font> <\/font>\n2<\/a> myIntList<\/font>.add<\/font>(<\/strong><\/font>new<\/strong> Integer<\/font>(<\/strong><\/font>0<\/font>)<\/strong><\/font>)<\/strong><\/font>;<\/font> <\/font>\n3<\/a> Integer<\/font> x<\/font> =<\/font> myIntList<\/font>.iterator<\/font>(<\/strong><\/font>)<\/strong><\/font>.next<\/font>(<\/strong><\/font>)<\/strong><\/font>;<\/font> <\/font>\n<\/pre>\n
Here is the source snippet of java.util.Collection class from the 1.5 version. Makes me wipe the sweat.<\/p>\n
\n1<\/a> public<\/strong> interface<\/strong> Collection<\/font><<\/font>E<\/font>><\/font> extends<\/strong> Iterable<\/font><<\/font>E<\/font>><\/font> {<\/strong><\/font>\n2<\/a> <<\/font>T<\/font>><\/font> T<\/font>[<\/strong><\/font>]<\/strong><\/font> toArray<\/font>(<\/strong><\/font>T<\/font>[<\/strong><\/font>]<\/strong><\/font> a<\/font>)<\/strong><\/font>;<\/font>\n3<\/a> boolean<\/strong> containsAll<\/font>(<\/strong><\/font>Collection<\/font><<\/font>?><\/font> c<\/font>)<\/strong><\/font>;<\/font>\n4<\/a> boolean<\/strong> addAll<\/font>(<\/strong><\/font>Collection<\/font><<\/font>? extends<\/strong> E<\/font>><\/font> c<\/font>)<\/strong><\/font>;<\/font>\n5<\/a> Iterator<\/font><<\/font>E<\/font>><\/font> iterator<\/font>(<\/strong><\/font>)<\/strong><\/font>;<\/font>\n6<\/a> }<\/strong><\/font>\n<\/pre>\n
Yeah, yeah. The fans of C++ would love it, it looks like the C++ templates, compile-time type checking, etc. — Well, programmers shall figure out other ways of making mistakes like working on a null object :D)
\nNo way out, I need to learn it ‘coz 1.6 is already out and I was still hanging on to 1.4 till yesterday!<\/p>\n","protected":false},"excerpt":{"rendered":"
Coding in Java was simple until Java 5 (or Java 1.5 — 1.5 is the developer version and Java 5 is the marketing version as Sun calls it!). Learning generics in Java 1.5 is like learning Microsoft COM programming, it would take at least 5 passes to absorb it right. Look at this simple call, […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[10],"tags":[],"_links":{"self":[{"href":"https:\/\/www.khaitan.org\/blog\/wp-json\/wp\/v2\/posts\/255"}],"collection":[{"href":"https:\/\/www.khaitan.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.khaitan.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.khaitan.org\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.khaitan.org\/blog\/wp-json\/wp\/v2\/comments?post=255"}],"version-history":[{"count":0,"href":"https:\/\/www.khaitan.org\/blog\/wp-json\/wp\/v2\/posts\/255\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.khaitan.org\/blog\/wp-json\/wp\/v2\/media?parent=255"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.khaitan.org\/blog\/wp-json\/wp\/v2\/categories?post=255"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.khaitan.org\/blog\/wp-json\/wp\/v2\/tags?post=255"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}