本文整理了Java中cascading.tuple.Tuple.extract()方法的一些代码示例，展示了Tuple.extract()的具体用法。这些代码示例主要来源于Github/Stackoverflow/Maven等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定程度帮忙到你。Tuple.extract()方法的具体详情如下：
包路径：cascading.tuple.Tuple
类名称：Tuple
方法名：extract

Tuple.extract介绍

[英]Creates a new Tuple from the given positions, but sets the values in the current tuple to null.
[中]从给定位置创建新元组，但将当前元组中的值设置为null。

代码示例

代码示例来源：origin: cwensel/cascading

/**
 * Method extract creates a new Tuple from the given selector, but sets the values in the current tuple to null.
 *
 * @param tupleEntry of type TupleEntry
 * @param selector   of type Fields
 * @return Tuple
 */
public static Tuple extract( TupleEntry tupleEntry, Fields selector )
 {
 return tupleEntry.tuple.extract( tupleEntry.getFields().getPos( selector, tupleEntry.getFields().size() ) );
 }

代码示例来源：origin: cwensel/cascading

@Test
public void testExtractSet()
 {
 Tuple aTuple = tuple.extract( new int[]{0} );
 assertEquals( "not equal: aTuple.size()", 1, aTuple.size() );
 assertEquals( "not equal: aTuple.get( 0 )", "a", aTuple.getObject( 0 ) );
 assertEquals( "not equal: tuple.size()", 5, tuple.size() );
 assertEquals( "not equal: tuple.get( 0 )", null, tuple.getObject( 0 ) );
 assertEquals( "not equal: tuple.get( 0 )", "b", tuple.getObject( 1 ) );
 assertEquals( "not equal: tuple.get( 1 )", "c", tuple.getObject( 2 ) );
 tuple.set( new int[]{0}, new Tuple( "A" ) );
 assertEquals( "not equal: tuple.size()", 5, tuple.size() );
 assertEquals( "not equal: tuple.get( 0 )", "A", tuple.getObject( 0 ) );
 assertEquals( "not equal: tuple.get( 0 )", "b", tuple.getObject( 1 ) );
 assertEquals( "not equal: tuple.get( 1 )", "c", tuple.getObject( 2 ) );
 }