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This commit is contained in:
Niket Agrawal 2023-10-05 11:44:52 +05:30
parent 4efa2ba820
commit fe6bb0e286
2 changed files with 110 additions and 0 deletions
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6
core-java-modules/core-java-streams-5/pom.xml
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@ -43,6 +43,12 @@
<artifactId>vavr</artifactId>
<version>${vavr.version}</version>
</dependency>
<dependency>
<groupId>com.codepoetics</groupId>
<artifactId>protonpack</artifactId>
<version>1.16</version>
</dependency>
</dependencies>
<build>

104
core-java-modules/core-java-streams-5/src/test/java/com/baeldung/streams/firstmatchingelement/FirstMatchingElementUnitTest.java Normal file
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@ -0,0 +1,104 @@
package com.baeldung.streams.firstmatchingelement;
import static org.junit.jupiter.api.Assertions.assertEquals;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Optional;
import java.util.OptionalInt;
import java.util.stream.IntStream;
import org.assertj.core.util.Lists;
import org.junit.Test;
import com.codepoetics.protonpack.StreamUtils;
public class FirstMatchingElementUnitTest {
@Test
public void testWithForLoop() {
List<Object> dataList = Lists.newArrayList("String", 1, Boolean.TRUE);
int index = -1;
for (int i = 0; i < dataList.size(); i++) {
if (dataList.get(i) instanceof Boolean) {
index = i;
}
}
assertEquals(2, index);
}
@Test
public void testWithIndexOf() {
List<Object> dataList = Lists.newArrayList("String", 1, Boolean.TRUE);
Optional<Object> booleanData = dataList.stream()
.filter(data -> data instanceof Boolean)
.findFirst();
int index = booleanData.isPresent() ? dataList.indexOf(booleanData.get()) : -1;
assertEquals(2, index);
}
@Test
public void testWithIterator() {
List<Object> dataList = Lists.newArrayList("String", 1, Boolean.TRUE);
int index = -1;
Iterator<Object> iterator = dataList.iterator();
while (iterator.hasNext()) {
Object data = iterator.next();
if (data instanceof Boolean) {
index = dataList.indexOf(data);
break;
}
}
assertEquals(2, index);
}
@Test
public void testWithListIterator() {
List<Object> dataList = Lists.newArrayList("String", 1, Boolean.TRUE);
int index = -1;
ListIterator<Object> listIterator = dataList.listIterator();
while (listIterator.hasNext()) {
if (listIterator.next() instanceof Boolean) {
index = listIterator.previousIndex();
break;
}
}
assertEquals(2, index);
}
@Test
public void testWithTakeAWhile() {
List<Object> dataList = Lists.newArrayList("String", 1, Boolean.TRUE, 2, 3);
OptionalInt booleanIndex = dataList.stream()
.takeWhile(data -> !(data instanceof Boolean))
.mapToInt(dataList::indexOf)
.max();
if (booleanIndex.isPresent() && dataList.get(booleanIndex.getAsInt()) instanceof Boolean) {
assertEquals(2, booleanIndex.getAsInt());
}
}
@Test
public void testWithIntStream() {
List<Object> dataList = Lists.newArrayList("String", 1, Boolean.TRUE);
int index = IntStream.of(0, dataList.size() - 1)
.filter(streamIndex -> dataList.get(streamIndex) instanceof Boolean)
.findFirst()
.orElse(-1);
assertEquals(2, index);
}
@Test
public void testWithZipWithIndex() {
List<Object> dataList = Lists.newArrayList("String", 1, Boolean.TRUE, 2, 3);
int index = StreamUtils.zipWithIndex(dataList.stream())
.filter(i -> i.getValue() instanceof Boolean)
.mapToInt(i -> Long.valueOf(i.getIndex())
.intValue())
.findFirst()
.orElse(-1);
assertEquals(2, index);
}
}