41 lines
1.5 KiB
Java
41 lines
1.5 KiB
Java
import java.util.ArrayList;
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import java.util.Arrays;
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import java.util.List;
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import java.util.Map;
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import java.util.stream.Collectors;
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import java.util.stream.Stream;
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public class ExampleStreamConversion {
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public static void main(String[] args) {
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//stream to list
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//1
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Stream<Integer> numStream = Stream.of(1,2,3,4,5,6,7);
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List<Integer> numList = numStream.collect(Collectors.toList());
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System.out.println(numList);
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//2
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numStream = Stream.of(1,2,3,4,5,6,7);
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List<Integer> numList1 = numStream.collect(Collectors.toCollection(ArrayList::new));
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//3
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Stream<Integer> numStream2 = Stream.of(1,2,3,4,5,6,7);
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List<Integer> numList2 = new ArrayList<>();
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numStream2.forEach(numList::add);
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//stream to map
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Stream<String[]> mapStream = Stream.of(new String[][]{{"1", "one"}, {"2", "two"}});
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Map<String, String> finalMap = mapStream.collect(Collectors.toMap(e -> e[0], e -> e[1]));
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System.out.println(finalMap);
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//stream to array
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//1
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Stream<Integer> intStream = Stream.of(1, 2, 3, 4, 5, 6);
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Integer[] intArray = intStream.toArray(Integer[]::new);
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System.out.println(Arrays.toString(intArray));
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//2
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Stream<Integer> intStream2 = Stream.of(1, 2, 3, 4, 5, 6);
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int[] intArray2 = intStream2.mapToInt(i -> i).toArray();
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}
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}
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