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added updated example codes (#2062)

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Seun Matt 2017-06-13 11:58:53 +01:00 committed by Grzegorz Piwowarek
parent f73893bbb9
commit 53f4ec5f87
2 changed files with 41 additions and 20 deletions
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47
core-java/src/main/java/com/baeldung/string/StringToCharStream.java
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@ -12,29 +12,40 @@ public class StringToCharStream {
public StringToCharStream() {
//let's use the Stream API to manipulate a string
//this will count the occurrence of each character in the test string
//let's use the Stream API to manipulate a string
//this will count the occurrence of each character in the test string
System.out.println("Counting Occurrence of Letter");
String testString = "Noww";
String testString = "tests";
//we don't want to use foreach, so . . .
//first get an IntStream
IntStream intStream = testString.chars();
IntStream intStream1 = testString.codePoints();
Map<Character, Integer> map = new HashMap<>();
//now let's map them
Stream<Character> characterStream = intStream.mapToObj(c -> (char) c);
Stream<Character> characterStream1 = intStream1.mapToObj(c -> (char) c);
testString.codePoints()
.mapToObj(c -> (char) c)
.filter(c -> Character.isLetter(c))
.forEach(c -> {
if(map.containsKey(c)) {
map.put(c, map.get(c) + 1);
} else {
map.put(c, 1);
}
});
System.out.println("Counting Occurrence of Letter");
testString = "Noww";
//we don't want to use foreach, so . . .
Map<Character, Integer> map = new HashMap<>();
testString.codePoints()
.mapToObj(c -> (char) c)
.filter(c -> Character.isLetter(c))
.forEach(c -> {
if(map.containsKey(c)) {
map.put(c, map.get(c) + 1);
} else {
map.put(c, 1);
}
});
//printing out the result here
System.out.println(map.toString());
//printing out the result here
System.out.println(map.toString());
}

14
core-java/src/test/java/com/baeldung/string/StringToCharStreamUnitTest.java
View File

@ -5,7 +5,9 @@ import org.junit.Test;
import java.util.stream.IntStream;
import java.util.stream.Stream;
import static org.hamcrest.CoreMatchers.instanceOf;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertThat;
import static org.junit.Assert.assertTrue;
/**
@ -17,12 +19,13 @@ public class StringToCharStreamUnitTest {
@Test
public void givenTestString_whenChars_thenReturnIntStream() {
assertTrue(testString.chars() instanceof IntStream);
assertThat(testString.chars(), instanceOf(IntStream.class));
}
@Test
public void givenTestString_whenCodePoints_thenReturnIntStream() {
assertTrue(testString.codePoints() instanceof IntStream);
assertThat(testString.codePoints(), instanceOf(IntStream.class));
}
@Test
@ -33,4 +36,11 @@ public class StringToCharStreamUnitTest {
assertNotNull("IntStream returned by codePoints() did not map to Stream<Character>", characterStream1);
}
@Test
public void givenIntStream_whenMapToObj_thenReturnStringStream(){
Stream<String> stringStream
= testString.codePoints().mapToObj(c -> String.valueOf((char) c));
assertNotNull(stringStream);
}
}