[modify-print-list] modify + print a list

This commit is contained in:
Kai.Yuan 2024-02-24 10:18:09 +08:00
parent bd36eddeca
commit 0648a4f918
2 changed files with 57 additions and 1 deletions

View File

@ -0,0 +1,56 @@
package com.baeldung.modifyandprint;
import static org.junit.jupiter.api.Assertions.assertEquals;
import java.util.List;
import java.util.stream.Collectors;
import org.junit.jupiter.api.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.collect.Lists;
public class ModifyAndPrintListElementsUnitTest {
private final Logger log = LoggerFactory.getLogger(ModifyAndPrintListElementsUnitTest.class);
@Test
void whenPrintingInForEach_thenListIsPrinted() {
List<String> theList = Lists.newArrayList("Kai", "Liam", "Eric", "Kevin");
theList.forEach(e -> log.info(e));
}
@Test
void whenUsingModifyAndPrintingSeparately_thenListIsModifiedAndPrinted() {
List<String> theList = Lists.newArrayList("Kai", "Liam", "Eric", "Kevin");
theList.replaceAll(e -> e.toUpperCase());
theList.forEach(e -> log.info(e));
assertEquals(List.of("KAI", "LIAM", "ERIC", "KEVIN"), theList);
}
@Test
void whenPrintingInMap_thenStreamIsModifiedAndPrinted() {
List<String> theList = List.of("Kai", "Liam", "Eric", "Kevin");
List<String> newList = theList.stream()
.map(e -> {
String newElement = e.toUpperCase();
log.info(newElement);
return newElement;
})
.filter(e -> e.length() == 4)
.collect(Collectors.toList());
assertEquals(List.of("LIAM", "ERIC"), newList);
}
@Test
void whenPrintingInPeek_thenStreamIsModifiedAndPrinted() {
List<String> theList = List.of("Kai", "Liam", "Eric", "Kevin");
List<String> newList = theList.stream()
.map(e -> e.toUpperCase())
.peek(e -> log.info(e))
.filter(e -> e.length() == 4)
.collect(Collectors.toList());
assertEquals(List.of("LIAM", "ERIC"), newList);
}
}