Javatuples of Java tuple types

Reprint: Java meta-group type Javatuples

With respect to the return value of a method, it is often necessary to return a sequence of 2 or more values, such as a record of a data table, a row of files, and so on. In addition to using array arrays, collections (list, set, MAP) of these container types, in Java we have to create a class to be the return type.

Tuple-type support is provided in many languages, such as the. NET Framework supports a maximum of 7 element tuples, refer to here:

C # code

var New tuple<stringintint int int int int.int>(                              " New York " 7891957 7781984 ,                               7894862 7071639 7322564 8008278);  

Scala supports up to 22 elements of tuples, see here:

JS Code

New Tuple4 (4,3,2,1)  //  syntactic sugar    = t._1 + t._2 + t._3 + t._4  

For the C + + (STL) tuple, refer to here:

C + + code

tuple<intstringstring> t (5"foo"" Bar " );   << T.get<1> ();  // outputs "foo"  

First look at Java if you want to return the "one" key value pair, what should I do?

(1) Apache Struts1 's Labelvaluebean

Java code

New Labelvaluebean ("rensanning.iteye.com", "9527");  

(2) Guava's maps.immutableentry

Java code

map.entry<string,integer> Entry2 = maps.immutableentry ("rensanning.iteye.com", 9527);  

(3) Apache Commons-collections's KeyValue

Java code

New Defaultmapentry ("rensanning.iteye.com", 9527);  KeyValueNew defaultkeyvalue ("rensanning.iteye.com", 9527);  

(4) Apache Commons-lang3 's pair

Java code

1 New Immutablepair<string, integer> ("rensanning.iteye.com", 9527);  

(5) Apache HttpClient's Namevaluepair

Java code

1 New Basicnamevaluepair ("rensanning.iteye.com", "9527");  

(6) Android pair

Java code

1 New Pair<string, integer> ("rensanning.iteye.com", 9527);  

。。。。。。 And so many more, you can also expand your own map.entry or package class.

Java 6 provides abstractmap.simpleentry<k,v> and abstractmap.simpleimmutableentry<k,v>

Java code

1 New Abstractmap.simpleentry<string, integer> ("rensanning.iteye.com", 9527);  

The two entity as static to embed in the Abstractmap marked as abstract, this API is quite strange!

Javatuples is a very simple lib, it does not have any gorgeous function, is to provide support to return multiple elements of some classes.

Https://github.com/javatuples/javatuples

Version: Javatuples-1.2.jar

Supports a maximum of 10 elements:

• Unit<a> (1 Element)
• Pair<a,b> (2 elements)
• Triplet<a,b,c> (3 elements)
• Quartet<a,b,c,d> (4 elements)
• Quintet<a,b,c,d,e> (5 elements)
• Sextet<a,b,c,d,e,f> (6 elements)
• Septet<a,b,c,d,e,f,g> (7 elements)
• Octet<a,b,c,d,e,f,g,h> (8 elements)
• Ennead<a,b,c,d,e,f,g,h,i> (9 elements)
• Decade<a,b,c,d,e,f,g,h,i,j> (elements)

Commonly used 2-tuple pair:

• Keyvalue<a,b>
• Labelvalue<a,b>

Java code

1 //1 tuples2unit<string> U =NewUnit<string> ("rensanning.iteye.com"); 3 //2 tuples4Pair<string,integer> p = pair.with ("rensanning.iteye.com", 9527); 5 //3 tuples6triplet<string,integer,double> Triplet = Triplet.with ("rensanning.iteye.com", 9527, 1.0); 7 //...  8           9keyvalue<string,string> kv = Keyvalue.with ("rensanning.iteye.com", "9527"); Tenlabelvalue<string,string> LV = labelvalue.with ("rensanning.iteye.com", "9527");

Reference Links:
http://tech.puredanger.com/2010/03/31/do-we-want-a-java-util-pair/
Http://mail.openjdk.java.net/pipermail/core-libs-dev/2010-March/003995.html

Javatuples of Java tuple types