Javatuples 简明教程

JavaTuples - Conversion

Tuple to List/Array

元组可以转换成 List/Array，但会损失类型安全性，转换后的列表是 List<Object>/Object[] 类型。

A tuple can be converted to List/Array but at cost of type safety and converted list is of type List<Object>/Object[].

List<Object> list = triplet.toList();
Object[] array = triplet.toArray();

Collection/Array to Tuple

集合可以使用fromCollection()方法转换成元组，数组可以使用fromArray()方法转换成元组。

A collection can be converted to tuple using fromCollection() method and array can be converted to tuple using fromArray() method.

Pair<String, Integer> pair = Pair.fromCollection(list);
Quartet<String,String,String,String> quartet = Quartet.fromArray(array);

如果数组/集合的大小与元组不同，则会发生 IllegalArgumentException。

If size of array/collection is different than that of tuple, then IllegalArgumentException will occur.

Exception in thread "main" java.lang.IllegalArgumentException:
Array must have exactly 4 elements in order to create a Quartet. Size is 5
   at ...

Example

让我们来看看 JavaTuples 的实际应用。这里我们将看到如何将元组转换成列表/数组，反之亦然。

Let’s see JavaTuples in action. Here we’ll see how to convert tuple to list/array and vice versa.

在 C:&gt;JavaTuples 中创建一个名为 TupleTester 的 Java 类文件。

Create a java class file named TupleTester in C:\>JavaTuples.

文件：TupleTester.java

File: TupleTester.java

package com.tutorialspoint;
import java.util.List;
import org.javatuples.Quartet;
import org.javatuples.Triplet;
public class TupleTester {
   public static void main(String args[]){
      Triplet<String, Integer, String> triplet = Triplet.with(
         "Test1", Integer.valueOf(5), "Test2"
      );
      List<Object> list = triplet.toList();
      Object[] array = triplet.toArray();
      System.out.println("Triplet:" + triplet);
      System.out.println("List: " + list);
      System.out.println();
      for(Object object: array) {
         System.out.print(object + " " );
      }
      System.out.println();
      String[] strArray = new String[] {"a", "b" , "c" , "d"};
      Quartet<String, String, String, String> quartet = Quartet.fromArray(strArray);
      System.out.println("Quartet:" + quartet);
   }
}

Verify the result

Verify the result

使用以下 javac 编译器编译类：

Compile the classes using javac compiler as follows −

C:\JavaTuples>javac -cp javatuples-1.2.jar ./com/tutorialspoint/TupleTester.java

现在运行 TupleTester 查看结果：

Now run the TupleTester to see the result −

C:\JavaTuples>java  -cp .;javatuples-1.2.jar com.tutorialspoint.TupleTester

Output

验证输出

Verify the Output

Triplet:[Test1, 5, Test2]
List: [Test1, 5, Test2]

Test1 5 Test2
Quartet:[a, b, c, d]