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Refactor hashcode() samples (#2377)

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This commit is contained in:
Grzegorz Piwowarek 2017-08-05 22:07:50 +02:00 committed by GitHub
parent 67448de055
commit ae827f3122
7 changed files with 15 additions and 203 deletions
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39
core-java/hashcode/pom.xml
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@ -1,39 +0,0 @@
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.baeldung.hashcode</groupId>
<artifactId>hashcode</artifactId>
<version>1.0</version>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
<dependencies>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.7.25</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.7.25</version>
</dependency>
</dependencies>
</project>

23
core-java/hashcode/src/main/java/com/baeldung/application/Application.java
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@ -1,23 +0,0 @@
package com.baeldung.application;
import com.baeldung.entities.User;
import java.util.HashMap;
import java.util.Map;
public class Application {
public static void main(String[] args) {
Map<User, User> users = new HashMap<>();
User user1 = new User(1L, "John", "john@domain.com");
User user2 = new User(2L, "Jennifer", "jennifer@domain.com");
User user3 = new User(3L, "Mary", "mary@domain.com");
users.put(user1, user1);
users.put(user2, user2);
users.put(user3, user3);
if (users.containsKey(user1)) {
System.out.print("User found in the collection");
}
}
}

38
core-java/hashcode/src/main/java/com/baeldung/entities/User.java
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@ -1,38 +0,0 @@
package com.baeldung.entities;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class User {
private final Logger logger = LoggerFactory.getLogger(User.class);
private long id;
private String name;
private String email;
public User(long id, String name, String email) {
this.id = id;
this.name = name;
this.email = email;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null) return false;
if (this.getClass() != o.getClass()) return false;
User user = (User) o;
return id != user.id && (!name.equals(user.name) && !email.equals(user.email));
}
@Override
public int hashCode() {
int hash = 7;
hash = 31 * hash + (int) id;
hash = 31 * hash + (name == null ? 0 : name.hashCode());
hash = 31 * hash + (email == null ? 0 : email.hashCode());
logger.info("hashCode() method called - Computed hash: " + hash);
return hash;
}
// getters and setters here
}

30
core-java/hashcode/src/test/java/com/baeldung/application/ApplicationTest.java
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@ -1,30 +0,0 @@
package com.baeldung.application;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import static org.junit.Assert.assertEquals;
public class ApplicationTest {
private ByteArrayOutputStream outContent;
@Before
public void setUpPrintStreamInstance() throws Exception {
this.outContent = new ByteArrayOutputStream();
System.setOut(new PrintStream(outContent));
}
@After
public void tearDownByteArrayOutputStream() throws Exception {
outContent = null;
}
@Test
public void main_NoInputState_TextPrintedToConsole() throws Exception {
Application.main(new String[]{});
assertEquals("User found in the collection", outContent.toString());
}
}

34
core-java/hashcode/src/test/java/com/baeldung/entities/UserTest.java
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@ -1,34 +0,0 @@
package com.baeldung.entities;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
public class UserTest {
private User user;
private User comparisonUser;
@Before
public void setUpUserInstances() {
this.user = new User(1L, "test", "test@domain.com");
this.comparisonUser = this.user;
}
@After
public void tearDownUserInstances() {
user = null;
comparisonUser = null;
}
@Test
public void equals_EqualUserInstance_TrueAssertion(){
Assert.assertTrue(user.equals(comparisonUser));
}
@Test
public void hashCode_UserHash_TrueAssertion() {
Assert.assertEquals(1792276941, user.hashCode());
}
}

24
core-java/src/main/java/com/baeldung/hashcode/application/Application.java
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@ -1,24 +0,0 @@
package com.baeldung.hashcode.application;
import java.util.HashMap;
import java.util.Map;
import com.baeldung.hashcode.entities.User;
public class Application {
public static void main(String[] args) {
Map<User, User> users = new HashMap<>();
User user1 = new User(1L, "John", "john@domain.com");
User user2 = new User(2L, "Jennifer", "jennifer@domain.com");
User user3 = new User(3L, "Mary", "mary@domain.com");
users.put(user1, user1);
users.put(user2, user2);
users.put(user3, user3);
if (users.containsKey(user1)) {
System.out.print("User found in the collection");
}
}
}

30
core-java/src/test/java/com/baeldung/hashcode/application/ApplicationTest.java
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@ -1,30 +1,30 @@
package com.baeldung.hashcode.application;
import com.baeldung.hashcode.entities.User;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import java.io.ByteArrayOutputStream;
import java.io.PrintStream;
import java.util.HashMap;
import java.util.Map;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
public class ApplicationTest {
private ByteArrayOutputStream outContent;
@Before
public void setUpPrintStreamInstance() throws Exception {
this.outContent = new ByteArrayOutputStream();
System.setOut(new PrintStream(outContent));
}
@After
public void tearDownByteArrayOutputStream() throws Exception {
outContent = null;
}
@Test
public void main_NoInputState_TextPrintedToConsole() throws Exception {
Application.main(new String[] {});
assertEquals("User found in the collection", outContent.toString());
Map<User, User> users = new HashMap<>();
User user1 = new User(1L, "John", "john@domain.com");
User user2 = new User(2L, "Jennifer", "jennifer@domain.com");
User user3 = new User(3L, "Mary", "mary@domain.com");
users.put(user1, user1);
users.put(user2, user2);
users.put(user3, user3);
assertTrue(users.containsKey(user1));
}
}