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optional orelse optional ex

This commit is contained in:
Loredana Crusoveanu 2018-05-27 15:42:59 +03:00
parent 146c1bb2a9
commit ca9f1bbc42
3 changed files with 83 additions and 0 deletions
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6
core-java-9/pom.xml
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@ -47,6 +47,11 @@
<version>${awaitility.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.google.guava</groupId>
<artifactId>guava</artifactId>
<version>${guava.version}</version>
</dependency>
</dependencies>
<build>
@ -89,6 +94,7 @@
<awaitility.version>1.7.0</awaitility.version>
<maven.compiler.source>1.9</maven.compiler.source>
<maven.compiler.target>1.9</maven.compiler.target>
<guava.version>25.1-jre</guava.version>
</properties>
</project>

26
core-java-9/src/main/java/com/baeldung/optionals/Optionals.java Normal file
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@ -0,0 +1,26 @@
package com.baeldung.optionals;
import java.util.Optional;
public class Optionals {
public static <T> Optional<T> or(Optional<T> optional, Optional<T> fallback) {
return optional.isPresent() ? optional : fallback;
}
public static Optional<String> getName(Optional<String> name) {
return name.or(() -> getCustomMessage());
}
public static com.google.common.base.Optional<String> getOptionalGuavaName(com.google.common.base.Optional<String> name) {
return name.or(getCustomMessageGuava());
}
private static Optional<String> getCustomMessage() {
return Optional.of("Name not provided");
}
private static com.google.common.base.Optional<String> getCustomMessageGuava() {
return com.google.common.base.Optional.of("Name not provided");
}
}

51
core-java-9/src/test/java/com/baeldung/optionals/OptionalsTest.java Normal file
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@ -0,0 +1,51 @@
package com.baeldung.optionals;
import static org.junit.Assert.assertEquals;
import java.util.Optional;
import org.junit.Test;
public class OptionalsTest {
@Test
public void givenOptional_whenEmptyValue_thenCustomMessage() {
assertEquals(Optional.of("Name not provided"), Optionals.getName(Optional.ofNullable(null)));
}
@Test
public void givenOptional_whenValue_thenOptional() {
String name = "Filan Fisteku";
Optional<String> optionalString = Optional.ofNullable(name);
assertEquals(optionalString, Optionals.getName(optionalString));
}
@Test
public void givenOptional_whenValue_thenOptionalGeneralMethod() {
String name = "Filan Fisteku";
String missingOptional = "Name not provided";
Optional<String> optionalString = Optional.ofNullable(name);
Optional<String> fallbackOptionalString = Optional.ofNullable(missingOptional);
assertEquals(optionalString, Optionals.or(optionalString, fallbackOptionalString));
}
@Test
public void givenEmptyOptional_whenValue_thenOptionalGeneralMethod() {
String missingOptional = "Name not provided";
Optional<String> optionalString = Optional.empty();
Optional<String> fallbackOptionalString = Optional.ofNullable(missingOptional);
assertEquals(fallbackOptionalString, Optionals.or(optionalString, fallbackOptionalString));
}
@Test
public void givenGuavaOptional_whenInvoke_thenOptional() {
String name = "Filan Fisteku";
com.google.common.base.Optional<String> stringOptional = com.google.common.base.Optional.of(name);
assertEquals(stringOptional, Optionals.getOptionalGuavaName(stringOptional));
}
@Test
public void givenGuavaOptional_whenNull_thenDefaultText() {
assertEquals(com.google.common.base.Optional.of("Name not provided"), Optionals.getOptionalGuavaName(com.google.common.base.Optional.fromNullable(null)));
}
}