iSharkFly-Open/Java-Tutorials
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Merge branch 'eugenp:master' into master

Browse Source
This commit is contained in:
press0
2022-11-08 07:17:12 -06:00
committed by GitHub
parent 5eab831bb5 d0c3a7dfd6
commit 3c895d237e
552 changed files with 36042 additions and 1920 deletions
Download Patch File Download Diff File Expand all files Collapse all files
.gitignore
+3
View File
@@ -65,6 +65,9 @@ core-java-io/target_link.txt
core-java/src/main/java/com/baeldung/manifest/MANIFEST.MF
ethereum/logs/
jmeter/src/main/resources/*-JMeter.csv
jmeter/src/main/resources/*-Basic*.csv
jmeter/src/main/resources/*-JMeter*.csv
ninja/devDb.mv.db
**/node_modules/
algorithms-modules/algorithms-sorting-2/README.md
+1
View File
@@ -4,4 +4,5 @@
- [Sorting Strings by Contained Numbers in Java](https://www.baeldung.com/java-sort-strings-contained-numbers)
- [Guide to In-Place Sorting Algorithm Works with a Java Implementation](https://www.baeldung.com/java-in-place-sorting)
- [Partitioning and Sorting Arrays with Many Repeated Entries with Java Examples](https://www.baeldung.com/java-sorting-arrays-with-repeated-entries)
- [Gravity/Bead Sort in Java](https://www.baeldung.com/java-gravity-bead-sort)
- More articles: [[<-- prev]](/algorithms-sorting)
algorithms-modules/algorithms-sorting-2/src/main/java/com/baeldung/algorithms/gravitysort/GravitySort.java
+60
View File
@@ -0,0 +1,60 @@
package com.baeldung.algorithms.gravitysort;
public class GravitySort {
public static int findMax(int[] A) {
int max = A[0];
for (int i = 1; i< A.length; i++) {
if (A[i] > max) {
max = A[i];
}
}
return max;
}
public static boolean[][] setupAbacus(int[] A, int m) {
boolean[][] abacus = new boolean[A.length][m];
for (int i = 0; i < abacus.length; i++) {
int number = A[i];
for (int j = 0; j < abacus[0].length && j < number; j++) {
abacus[A.length - 1 - i][j] = true;
}
}
return abacus;
}
public static void dropBeads(boolean[][] abacus, int[] A, int m) {
for (int i = 1; i < A.length; i++) {
for (int j = m - 1; j >= 0; j--) {
if (abacus[i][j] == true) {
int x = i;
while (x > 0 && abacus[x - 1][j] == false) {
boolean temp = abacus[x - 1][j];
abacus[x - 1][j] = abacus[x][j];
abacus[x][j] = temp;
x--;
}
}
}
}
}
public static void transformToList(boolean[][] abacus, int[] A) {
int index = 0;
for (int i = abacus.length - 1; i >= 0; i--) {
int beads = 0;
for (int j = 0; j < abacus[0].length && abacus[i][j] == true; j++) {
beads++;
}
A[index++] = beads;
}
}
public static void sort(int[] A) {
int m = findMax(A);
boolean[][] abacus = setupAbacus(A, m);
dropBeads(abacus, A, m);
// transform abacus into sorted list
transformToList(abacus, A);
}
}
algorithms-modules/algorithms-sorting-2/src/test/java/com/baeldung/algorithms/gravitysort/GravitySortUnitTest.java
+15
View File
@@ -0,0 +1,15 @@
package com.baeldung.algorithms.gravitysort;
import org.junit.Assert;
import org.junit.Test;
public class GravitySortUnitTest {
@Test
public void givenIntegerArray_whenSortedWithGravitySort_thenGetSortedArray() {
int[] actual = { 9, 9, 100, 3, 57, 12, 3, 78, 0, 2, 2, 40, 21, 9 };
int[] expected = { 0, 2, 2, 3, 3, 9, 9, 9, 12, 21, 40, 57, 78, 100 };
GravitySort.sort(actual);
Assert.assertArrayEquals(expected, actual);
}
}
aws-modules/aws-lambda/lambda/pom.xml
+2 -2
View File
@@ -95,8 +95,8 @@
<properties>
<json-simple.version>1.1.1</json-simple.version>
<aws-lambda-java-events.version>1.3.0</aws-lambda-java-events.version>
<aws-lambda-java-core.version>1.2.0</aws-lambda-java-core.version>
<aws-lambda-java-events.version>3.11.0</aws-lambda-java-events.version>
<aws-lambda-java-core.version>1.2.1</aws-lambda-java-core.version>
<gson.version>2.8.2</gson.version>
</properties>
aws-modules/aws-lambda/lambda/src/main/java/com/baeldung/lambda/dynamodb/SavePersonHandler.java
+21 -19
View File
@@ -1,12 +1,12 @@
package com.baeldung.lambda.dynamodb;
import com.amazonaws.regions.Region;
import java.util.HashMap;
import java.util.Map;
import com.amazonaws.regions.Regions;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClient;
import com.amazonaws.services.dynamodbv2.document.DynamoDB;
import com.amazonaws.services.dynamodbv2.document.Item;
import com.amazonaws.services.dynamodbv2.document.PutItemOutcome;
import com.amazonaws.services.dynamodbv2.document.spec.PutItemSpec;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDB;
import com.amazonaws.services.dynamodbv2.AmazonDynamoDBClientBuilder;
import com.amazonaws.services.dynamodbv2.model.AttributeValue;
import com.amazonaws.services.dynamodbv2.model.ConditionalCheckFailedException;
import com.amazonaws.services.lambda.runtime.Context;
import com.amazonaws.services.lambda.runtime.RequestHandler;
@@ -15,7 +15,7 @@ import com.baeldung.lambda.dynamodb.bean.PersonResponse;
public class SavePersonHandler implements RequestHandler<PersonRequest, PersonResponse> {
private DynamoDB dynamoDb;
private AmazonDynamoDB amazonDynamoDB;
private String DYNAMODB_TABLE_NAME = "Person";
private Regions REGION = Regions.US_WEST_2;
@@ -30,20 +30,22 @@ public class SavePersonHandler implements RequestHandler<PersonRequest, PersonRe
return personResponse;
}
private PutItemOutcome persistData(PersonRequest personRequest) throws ConditionalCheckFailedException {
return this.dynamoDb.getTable(DYNAMODB_TABLE_NAME)
.putItem(
new PutItemSpec().withItem(new Item()
.withNumber("id", personRequest.getId())
.withString("firstName", personRequest.getFirstName())
.withString("lastName", personRequest.getLastName())
.withNumber("age", personRequest.getAge())
.withString("address", personRequest.getAddress())));
private void persistData(PersonRequest personRequest) throws ConditionalCheckFailedException {
Map<String, AttributeValue> attributesMap = new HashMap<>();
attributesMap.put("id", new AttributeValue(String.valueOf(personRequest.getId())));
attributesMap.put("firstName", new AttributeValue(personRequest.getFirstName()));
attributesMap.put("lastName", new AttributeValue(personRequest.getLastName()));
attributesMap.put("age", new AttributeValue(String.valueOf(personRequest.getAge())));
attributesMap.put("address", new AttributeValue(personRequest.getAddress()));
amazonDynamoDB.putItem(DYNAMODB_TABLE_NAME, attributesMap);
}
private void initDynamoDbClient() {
AmazonDynamoDBClient client = new AmazonDynamoDBClient();
client.setRegion(Region.getRegion(REGION));
this.dynamoDb = new DynamoDB(client);
this.amazonDynamoDB = AmazonDynamoDBClientBuilder.standard()
.withRegion(REGION)
.build();
}
}
aws-modules/aws-reactive/pom.xml
+1 -1
View File
@@ -91,7 +91,7 @@
<properties>
<spring.version>2.2.1.RELEASE</spring.version>
<awssdk.version>2.10.27</awssdk.version>
<awssdk.version>2.17.283</awssdk.version>
</properties>
</project>
aws-modules/aws-reactive/src/main/java/com/baeldung/aws/reactive/s3/DownloadResource.java
+32 -80
View File
@@ -3,17 +3,11 @@
*/
package com.baeldung.aws.reactive.s3;
import java.io.InputStream;
import java.nio.ByteBuffer;
import java.util.Map;
import java.util.Map.Entry;
import java.util.concurrent.CompletableFuture;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.http.ResponseEntity.BodyBuilder;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
@@ -22,11 +16,7 @@ import org.springframework.web.bind.annotation.RestController;
import lombok.extern.slf4j.Slf4j;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import software.amazon.awssdk.core.ResponseBytes;
import software.amazon.awssdk.core.SdkResponse;
import software.amazon.awssdk.core.async.AsyncResponseTransformer;
import software.amazon.awssdk.core.async.SdkPublisher;
import software.amazon.awssdk.core.internal.async.ByteArrayAsyncResponseTransformer;
import software.amazon.awssdk.http.SdkHttpResponse;
import software.amazon.awssdk.services.s3.S3AsyncClient;
import software.amazon.awssdk.services.s3.model.GetObjectRequest;
@@ -40,38 +30,39 @@ import software.amazon.awssdk.services.s3.model.GetObjectResponse;
@RequestMapping("/inbox")
@Slf4j
public class DownloadResource {
private final S3AsyncClient s3client;
private final S3ClientConfigurarionProperties s3config;
public DownloadResource(S3AsyncClient s3client, S3ClientConfigurarionProperties s3config) {
this.s3client = s3client;
this.s3config = s3config;
this.s3config = s3config;
}
@GetMapping(path="/{filekey}")
public Mono<ResponseEntity<Flux<ByteBuffer>>> downloadFile(@PathVariable("filekey") String filekey) {
GetObjectRequest request = GetObjectRequest.builder()
.bucket(s3config.getBucket())
.key(filekey)
.build();
return Mono.fromFuture(s3client.getObject(request,new FluxResponseProvider()))
.map( (response) -> {
checkResult(response.sdkResponse);
String filename = getMetadataItem(response.sdkResponse,"filename",filekey);
log.info("[I65] filename={}, length={}",filename, response.sdkResponse.contentLength() );
return ResponseEntity.ok()
.header(HttpHeaders.CONTENT_TYPE, response.sdkResponse.contentType())
.header(HttpHeaders.CONTENT_LENGTH, Long.toString(response.sdkResponse.contentLength()))
.header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + filename + "\"")
.body(response.flux);
});
@GetMapping(path = "/{filekey}")
public Mono<ResponseEntity<Flux<ByteBuffer>>> downloadFile(@PathVariable("filekey") String filekey) {
GetObjectRequest request = GetObjectRequest.builder()
.bucket(s3config.getBucket())
.key(filekey)
.build();
return Mono.fromFuture(s3client.getObject(request, AsyncResponseTransformer.toPublisher()))
.map(response -> {
checkResult(response.response());
String filename = getMetadataItem(response.response(), "filename", filekey);
log.info("[I65] filename={}, length={}", filename, response.response()
.contentLength());
return ResponseEntity.ok()
.header(HttpHeaders.CONTENT_TYPE, response.response()
.contentType())
.header(HttpHeaders.CONTENT_LENGTH, Long.toString(response.response()
.contentLength()))
.header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + filename + "\"")
.body(Flux.from(response));
});
}
/**
@@ -82,63 +73,24 @@ public class DownloadResource {
* @return
*/
private String getMetadataItem(GetObjectResponse sdkResponse, String key, String defaultValue) {
for( Entry<String, String> entry : sdkResponse.metadata().entrySet()) {
if ( entry.getKey().equalsIgnoreCase(key)) {
for (Entry<String, String> entry : sdkResponse.metadata()
.entrySet()) {
if (entry.getKey()
.equalsIgnoreCase(key)) {
return entry.getValue();
}
}
return defaultValue;
}
// Helper used to check return codes from an API call
private static void checkResult(GetObjectResponse response) {
SdkHttpResponse sdkResponse = response.sdkHttpResponse();
if ( sdkResponse != null && sdkResponse.isSuccessful()) {
if (sdkResponse != null && sdkResponse.isSuccessful()) {
return;
}
throw new DownloadFailedException(response);
}
static class FluxResponseProvider implements AsyncResponseTransformer<GetObjectResponse,FluxResponse> {
private FluxResponse response;
@Override
public CompletableFuture<FluxResponse> prepare() {
response = new FluxResponse();
return response.cf;
}
@Override
public void onResponse(GetObjectResponse sdkResponse) {
this.response.sdkResponse = sdkResponse;
}
@Override
public void onStream(SdkPublisher<ByteBuffer> publisher) {
response.flux = Flux.from(publisher);
response.cf.complete(response);
}
@Override
public void exceptionOccurred(Throwable error) {
response.cf.completeExceptionally(error);
}
}
/**
* Holds the API response and stream
* @author Philippe
*/
static class FluxResponse {
final CompletableFuture<FluxResponse> cf = new CompletableFuture<>();
GetObjectResponse sdkResponse;
Flux<ByteBuffer> flux;
}
}
aws-modules/pom.xml
+1 -1
View File
@@ -22,7 +22,7 @@
</modules>
<properties>
<aws-java-sdk.version>1.11.290</aws-java-sdk.version>
<aws-java-sdk.version>1.12.331</aws-java-sdk.version>
<maven-shade-plugin.version>3.0.0</maven-shade-plugin.version>
</properties>
axon/README.md
+1 -1
View File
@@ -13,4 +13,4 @@ One script is included to easily start middleware using Docker:
- [A Guide to the Axon Framework](https://www.baeldung.com/axon-cqrs-event-sourcing)
- [Multi-Entity Aggregates in Axon](https://www.baeldung.com/java-axon-multi-entity-aggregates)
- [Snapshotting Aggregates in Axon](https://www.baeldung.com/axon-snapshotting-aggregates)
- [Dispatching Queries in Axon Framework](https://www.baeldung.com/axon-query-dispatching/)
- [Dispatching Queries in Axon Framework](https://www.baeldung.com/axon-query-dispatching)
baeldung-pmd-rules.xml
+4 -1
View File
@@ -3,7 +3,10 @@
xsi:schemaLocation="http://pmd.sf.net/ruleset/1.0.0 http://pmd.sf.net/ruleset_xml_schema.xsd"
xsi:noNamespaceSchemaLocation="http://pmd.sf.net/ruleset_xml_schema.xsd">
<description>Baeldung custom PMD rules</description>
<rule name="UnitTestMustFollowNamingConventionRule" message="Unit test class names need to end in 'UnitTest', integration tests with 'IntegrationTest', etc " class="org.baeldung.pmd.UnitTestNamingConventionRule">
<rule name="UnitTestMustFollowNamingConventionRule"
message="Unit test class names need to end in 'UnitTest', integration tests with 'IntegrationTest', etc "
class="org.baeldung.pmd.UnitTestNamingConventionRule"
language="java">
<description>Test does not follow Baeldung naming convention</description>
<priority>3</priority>
</rule>
core-java-modules/core-java-arrays-operations-advanced/src/test/java/com/baeldung/arrayslicing/SlicingArrayUnitTest.java
+43
View File
@@ -0,0 +1,43 @@
package com.baeldung.arrayslicing;
import org.apache.commons.lang3.ArrayUtils;
import org.junit.jupiter.api.Test;
import java.util.Arrays;
import static org.junit.jupiter.api.Assertions.assertArrayEquals;
public class SlicingArrayUnitTest {
private static final String[] LANGUAGES = new String[] { "Python", "Java", "Kotlin", "Scala", "Ruby", "Go", "Rust" };
private static final String[] JVM_LANGUAGES = new String[] { "Java", "Kotlin", "Scala" };
@Test
void givenAnArray_whenSlicingUsingStream_shouldGetExpectedResult() {
String[] result = Arrays.stream(LANGUAGES, 1, 4).toArray(String[]::new);
assertArrayEquals(JVM_LANGUAGES, result);
}
@Test
void givenAnArray_whenSlicingUsingArraysCopyOfRange_shouldGetExpectedResult() {
String[] result = Arrays.copyOfRange(LANGUAGES, 1, 4);
assertArrayEquals(JVM_LANGUAGES, result);
}
@Test
void givenAnArray_whenSlicingUsingSystemArraycopy_shouldGetExpectedResult() {
String[] result = new String[3];
System.arraycopy(LANGUAGES, 1, result, 0, 3);
assertArrayEquals(JVM_LANGUAGES, result);
String[] result2 = new String[] { "value one", "value two", "value three", "value four", "value five", "value six", "value seven" };
System.arraycopy(LANGUAGES, 1, result2, 2, 3);
assertArrayEquals(new String[] { "value one", "value two", "Java", "Kotlin", "Scala", "value six", "value seven" }, result2);
}
@Test
void givenAnArray_whenSlicingUsingArrayUtils_shouldGetExpectedResult() {
String[] result = ArrayUtils.subarray(LANGUAGES, 1, 4);
assertArrayEquals(JVM_LANGUAGES, result);
}
}
core-java-modules/core-java-arrays-operations-basic/README.md
+1
View File
@@ -10,3 +10,4 @@ This module contains articles about Java array fundamentals. They assume no prev
- [Removing an Element from an Array in Java](https://www.baeldung.com/java-array-remove-element)
- [Removing the First Element of an Array](https://www.baeldung.com/java-array-remove-first-element)
- [Extending an Array’s Length](https://www.baeldung.com/java-array-add-element-at-the-end)
- [Initializing a Boolean Array in Java](https://www.baeldung.com/java-initializing-boolean-array)
core-java-modules/core-java-collections-4/README.md
+1
View File
@@ -10,3 +10,4 @@
- [Create an Empty Map in Java](https://www.baeldung.com/java-create-empty-map)
- [Sorting Objects in a List by Date](https://www.baeldung.com/java-sort-list-by-date)
- [Fixed Size Queue Implementations in Java](https://www.baeldung.com/java-fixed-size-queue)
- [Difference Between Java Enumeration and Iterator](https://www.baeldung.com/java-enumeration-vs-iterator)
core-java-modules/core-java-collections-4/src/main/java/com/baeldung/enumerationiteratordifferences/DataUtil.java
+18
View File
@@ -0,0 +1,18 @@
package com.baeldung.enumerationiteratordifferences;
import java.util.Arrays;
import java.util.List;
public final class DataUtil {
private DataUtil() {
}
static List<Person> getPersons() {
Person person1 = new Person("amit", "kumar");
Person person2 = new Person("yogi", "kuki");
Person person3 = new Person("raj", "dosi");
Person person4 = new Person("prakash", "kumar");
return Arrays.asList(person1, person2, person3, person4);
}
}
core-java-modules/core-java-collections-4/src/main/java/com/baeldung/enumerationiteratordifferences/EnumerationExample.java
+19
View File
@@ -0,0 +1,19 @@
package com.baeldung.enumerationiteratordifferences;
import java.util.Enumeration;
import java.util.Vector;
import static com.baeldung.enumerationiteratordifferences.DataUtil.getPersons;
public class EnumerationExample {
public static void main(String[] args) {
Vector<Person> people = new Vector<>(getPersons());
Enumeration<Person> enumeration = people.elements();
while (enumeration.hasMoreElements()) {
System.out.println("First Name = " + enumeration.nextElement()
.getFirstName());
}
}
}
core-java-modules/core-java-collections-4/src/main/java/com/baeldung/enumerationiteratordifferences/IteratorExample.java
+17
View File
@@ -0,0 +1,17 @@
package com.baeldung.enumerationiteratordifferences;
import java.util.Iterator;
import java.util.List;
import static com.baeldung.enumerationiteratordifferences.DataUtil.getPersons;
public class IteratorExample {
public static void main(String[] args) {
List<Person> persons = getPersons();
Iterator<Person> iterator = persons.iterator();
while (iterator.hasNext()) {
System.out.println("First Name = " + iterator.next()
.getFirstName());
}
}
}
core-java-modules/core-java-collections-4/src/main/java/com/baeldung/enumerationiteratordifferences/Person.java
+27
View File
@@ -0,0 +1,27 @@
package com.baeldung.enumerationiteratordifferences;
public class Person {
private String firstName;
private String lastName;
public Person(String firstName, String lastName) {
this.firstName = firstName;
this.lastName = lastName;
}
public String getFirstName() {
return firstName;
}
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public String getLastName() {
return lastName;
}
public void setLastName(String lastName) {
this.lastName = lastName;
}
}
core-java-modules/core-java-collections-list-4/src/test/java/com/baeldung/list/tostring/ListToStringUnitTest.java
+2 -4
View File
@@ -27,15 +27,13 @@ class ListToStringUnitTest {
List<String> arraysAsList = Arrays.asList("ONE", "TWO", "THREE");
StringJoiner stringJoiner = new StringJoiner(",");
arraysAsList.stream()
.forEach(v -> stringJoiner.add(v));
arraysAsList.forEach(stringJoiner::add);
String commaSeparatedString = stringJoiner.toString();
assertThat(commaSeparatedString).isEqualTo("ONE,TWO,THREE");
StringJoiner stringJoinerWithDelimiterPrefixSuffix = new StringJoiner(",", "[", "]");
arraysAsList.stream()
.forEach(v -> stringJoinerWithDelimiterPrefixSuffix.add(v));
arraysAsList.forEach(stringJoinerWithDelimiterPrefixSuffix::add);
String commaSeparatedStringWithDelimiterPrefixSuffix = stringJoinerWithDelimiterPrefixSuffix.toString();
assertThat(commaSeparatedStringWithDelimiterPrefixSuffix).isEqualTo("[ONE,TWO,THREE]");
core-java-modules/core-java-collections-maps-2/pom.xml
+2 -2
View File
@@ -54,11 +54,11 @@
</dependencies>
<properties>
<streamex.version>0.6.5</streamex.version>
<streamex.version>0.8.1</streamex.version>
<avaitility.version>1.7.0</avaitility.version>
<eclipse-collections.version>8.2.0</eclipse-collections.version>
<hppc.version>0.7.2</hppc.version>
<fastutil.version>8.1.0</fastutil.version>
</properties>
</project>
</project>
core-java-modules/core-java-collections-maps-4/pom.xml
+7 -2
View File
@@ -15,6 +15,11 @@
</parent>
<dependencies>
<dependency>
<groupId>jakarta.ws.rs</groupId>
<artifactId>jakarta.ws.rs-api</artifactId>
<version>3.1.0</version>
</dependency>
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-collections4</artifactId>
@@ -62,8 +67,8 @@
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>1.9</maven.compiler.source>
<maven.compiler.target>1.9</maven.compiler.target>
<maven.compiler.source>11</maven.compiler.source>
<maven.compiler.target>11</maven.compiler.target>
</properties>
</project>
core-java-modules/core-java-collections-maps-4/src/test/java/com/baeldung/multivaluedmap/MultivaluedMapUnitTest.java
+43
View File
@@ -0,0 +1,43 @@
package com.baeldung.multivaluedmap;
import org.junit.jupiter.api.Test;
import java.util.HashMap;
import java.util.Map;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNotNull;
// Unit test for MultivaluedMap.
public class MultivaluedMapUnitTest {
// Testing MultivaluedHashMap.
@Test
public void givenMultivaluedHashMap_whenEquals_thenTrue() {
jakarta.ws.rs.core.MultivaluedMap<String, Integer> mulmap = new jakarta.ws.rs.core.MultivaluedHashMap<>();
// Mapping keys to values.
mulmap.addAll("first", 1, 2, 3);
mulmap.add(null, null);
assertNotNull(mulmap, "The MultivaluedHashMap is null!");
assertEquals(1, mulmap.getFirst("first"), "The key isn't mapped to the right values!");
assertEquals(null, mulmap.getFirst(null), "MultivaluedHashMap didn't accept null!");
}
// Testing HashMap.
@Test
public void givenHashMap_whenEquals_thenTrue() {
Map<String, Integer> map = new HashMap<>();
// Putting key-value pairs into our map.
map.put("first", 1);
map.put(null, 2);
map.put("third", null);
assertNotNull(map, "The HashMap is null!");
assertEquals(1, map.get("first"), "The key isn't mapped to the right value!");
assertEquals(2, map.get(null), "HashMap didn't accept null as key!");
assertEquals(null, map.get("third"), "HashMap didn't accept null value!");
}
}
core-java-modules/core-java-collections-set-2/README.md
+4
View File
@@ -0,0 +1,4 @@
## Relevant articles
- [Using Streams to Collect Into a TreeSet](https://www.baeldung.com/java-stream-collect-into-treeset)
- [A Guide to LinkedHashSet in Java](https://www.baeldung.com/java-linkedhashset)
core-java-modules/core-java-collections-set-2/pom.xml
+39
View File
@@ -0,0 +1,39 @@
<?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>
<artifactId>core-java-collections-set-2</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>core-java-collections-set-2</name>
<packaging>jar</packaging>
<parent>
<groupId>com.baeldung.core-java-modules</groupId>
<artifactId>core-java-modules</artifactId>
<version>0.0.1-SNAPSHOT</version>
</parent>
<dependencies>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>${maven-compiler-plugin.version}</version>
<configuration>
<source>${maven.compiler.source}</source>
<target>${maven.compiler.target}</target>
</configuration>
</plugin>
</plugins>
</build>
<properties>
<maven.compiler.source>8</maven.compiler.source>
<maven.compiler.target>8</maven.compiler.target>
</properties>
</project>
core-java-modules/core-java-collections-set-2/src/main/java/com/baeldung/treeset/collectintotreeset/Player.java
+36
View File
@@ -0,0 +1,36 @@
package com.baeldung.treeset.collectintotreeset;
public class Player implements Comparable<Player> {
private String name;
private int age;
private int numberOfPlayed;
private int numberOfWins;
public Player(String name, int age, int numberOfPlayed, int numberOfWins) {
this.name = name;
this.age = age;
this.numberOfPlayed = numberOfPlayed;
this.numberOfWins = numberOfWins;
}
public String getName() {
return name;
}
public int getAge() {
return age;
}
public int getNumberOfPlayed() {
return numberOfPlayed;
}
public int getNumberOfWins() {
return numberOfWins;
}
@Override
public int compareTo(Player o) {
return Integer.compare(age, o.age);
}
}
core-java-modules/core-java-collections-set-2/src/test/java/com/baeldung/linkedhashset/LinkedHashSetUnitTest.java
+141
View File
@@ -0,0 +1,141 @@
package com.baeldung.linkedhashset;
import org.junit.jupiter.api.Test;
import java.util.*;
import java.util.concurrent.atomic.AtomicInteger;
import static org.junit.Assert.*;
public class LinkedHashSetUnitTest{
@Test
void whenCreatingLinkedHashSet_shouldBeEmpty(){
Set<String> linkedHashSet = new LinkedHashSet<>();
assertTrue(linkedHashSet.isEmpty());
}
@Test
void whenCreatingLinkedHashSetWithInitialCapacity_shouldBeEmpty(){
LinkedHashSet<String> linkedHashSet = new LinkedHashSet<>(20);
assertTrue(linkedHashSet.isEmpty());
}
@Test
void whenCreatingLinkedHashSetWithExistingCollection_shouldContainAllElementOfCollection(){
Collection<String> data = Arrays.asList("first", "second", "third", "fourth", "fifth");
LinkedHashSet<String> linkedHashSet = new LinkedHashSet<>(data);
assertFalse(linkedHashSet.isEmpty());
assertEquals(data.size(), linkedHashSet.size());
assertTrue(linkedHashSet.containsAll(data) && data.containsAll(linkedHashSet));
}
@Test
void whenCreatingLinkedHashSetWithInitialCapacityAndLoadFactor_shouldBeEmpty(){
LinkedHashSet<String> linkedHashSet = new LinkedHashSet<>(20, 3);
assertTrue(linkedHashSet.isEmpty());
}
@Test
void whenAddingElement_shouldAddElement(){
Set<Integer> linkedHashSet = new LinkedHashSet<>();
assertTrue(linkedHashSet.add(0));
assertFalse(linkedHashSet.add(0));
assertTrue(linkedHashSet.contains(0));
}
@Test
void whenAddingCollection_shouldAddAllContentOfCollection(){
Collection<Integer> data = Arrays.asList(1,2,3);
LinkedHashSet<Integer> linkedHashSet = new LinkedHashSet<>();
assertTrue(linkedHashSet.addAll(data));
assertTrue(data.containsAll(linkedHashSet) && linkedHashSet.containsAll(data));
}
@Test
void whenAddingCollectionWithDuplicateElements_shouldMaintainUniqueValuesInSet(){
LinkedHashSet<Integer> linkedHashSet = new LinkedHashSet<>();
linkedHashSet.add(2);
Collection<Integer> data = Arrays.asList(1, 1, 2, 3);
assertTrue(linkedHashSet.addAll(data));
assertEquals(3, linkedHashSet.size());
assertTrue(data.containsAll(linkedHashSet) && linkedHashSet.containsAll(data));
}
@Test
void whenIteratingWithIterator_assertThatElementIsPresent(){
LinkedHashSet<Integer> linkedHashSet = new LinkedHashSet<>();
linkedHashSet.add(0);
linkedHashSet.add(1);
linkedHashSet.add(2);
Iterator<Integer> iterator = linkedHashSet.iterator();
for (int i = 0; i < linkedHashSet.size(); i++) {
int nextData = iterator.next();
assertEquals(i, nextData);
}
}
@Test
void whenIteratingWithSpliterator_assertThatElementIsPresent(){
LinkedHashSet<Integer> linkedHashSet = new LinkedHashSet<>();
linkedHashSet.add(0);
linkedHashSet.add(1);
linkedHashSet.add(2);
Spliterator<Integer> spliterator = linkedHashSet.spliterator();
AtomicInteger counter = new AtomicInteger();
spliterator.forEachRemaining(data -> {
assertEquals(counter.get(), (int)data);
counter.getAndIncrement();
});
}
@Test
void whenRemovingAnElement_shouldRemoveElement(){
Collection<String> data = Arrays.asList("first", "second", "third", "fourth", "fifth");
LinkedHashSet<String> linkedHashSet = new LinkedHashSet<>(data);
assertTrue(linkedHashSet.remove("second"));
assertFalse(linkedHashSet.contains("second"));
}
@Test
void whenRemovingAnElementGreaterThanTwo_shouldRemoveElement(){
LinkedHashSet<Integer> linkedHashSet = new LinkedHashSet<>();
linkedHashSet.add(0);
linkedHashSet.add(1);
linkedHashSet.add(2);
linkedHashSet.add(3);
linkedHashSet.add(4);
linkedHashSet.removeIf(data -> data > 2);
assertFalse(linkedHashSet.contains(3));
assertFalse(linkedHashSet.contains(4));
}
@Test
void whenRemovingAnElementWithIterator_shouldRemoveElement(){
LinkedHashSet<Integer> linkedHashSet = new LinkedHashSet<>();
linkedHashSet.add(0);
linkedHashSet.add(1);
linkedHashSet.add(2);
Iterator<Integer> iterator = linkedHashSet.iterator();
int elementToRemove = 1;
assertTrue(linkedHashSet.contains(elementToRemove));
while(iterator.hasNext()){
if(elementToRemove == iterator.next()){
iterator.remove();
}
}
assertFalse(linkedHashSet.contains(elementToRemove));
}
}
core-java-modules/core-java-collections-set-2/src/test/java/com/baeldung/treeset/collectintotreeset/CollectIntoTreeSetUnitTest.java
+52
View File
@@ -0,0 +1,52 @@
package com.baeldung.treeset.collectintotreeset;
import static org.assertj.core.api.Assertions.assertThat;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Comparator;
import java.util.TreeSet;
import java.util.stream.Collectors;
import java.util.stream.Stream;
import org.junit.jupiter.api.Test;
public class CollectIntoTreeSetUnitTest {
Player kai = new Player("Kai", 26, 28, 7);
Player eric = new Player("Eric", 28, 30, 11);
Player saajan = new Player("Saajan", 30, 100, 66);
Player kevin = new Player("Kevin", 24, 50, 49);
@Test
void givenAStream_whenCollectIntoTreeSetWithNaturalOrder_thenGetExpectedResult() {
String kotlin = "Kotlin";
String java = "Java";
String python = "Python";
String ruby = "Ruby";
TreeSet<String> myTreeSet = Stream.of(ruby, java, kotlin, python)
.collect(Collectors.toCollection(TreeSet::new));
assertThat(myTreeSet).containsExactly(java, kotlin, python, ruby);
}
@Test
void givenAPlayerStream_whenCollectIntoTreeSet_thenGetExpectedResult() {
TreeSet<Player> myTreeSet = Stream.of(saajan, eric, kai, kevin)
.collect(Collectors.toCollection(TreeSet::new));
assertThat(myTreeSet).containsExactly(kevin, kai, eric, saajan);
}
@Test
void givenAPlayerStream_whenCollectIntoTreeSetWithNoOfWinsComparator_thenGetExpectedResult() {
TreeSet<Player> myTreeSet = Stream.of(saajan, eric, kai, kevin)
.collect(Collectors.toCollection(() -> new TreeSet<>(Comparator.comparingInt(Player::getNumberOfWins))));
assertThat(myTreeSet).containsExactly(kai, eric, kevin, saajan);
}
@Test
void givenAPlayerStream_whenCollectIntoTreeSetWithWinRateComparator_thenGetExpectedResult() {
TreeSet<Player> myTreeSet = Stream.of(saajan, eric, kai, kevin)
.collect(Collectors.toCollection(() -> new TreeSet<>(Comparator.comparing(player -> BigDecimal.valueOf(player.getNumberOfWins())
.divide(BigDecimal.valueOf(player.getNumberOfPlayed()), 2, RoundingMode.HALF_UP)))));
assertThat(myTreeSet).containsExactly(kai, eric, saajan, kevin);
}
}
core-java-modules/core-java-concurrency-2/src/main/java/com/baeldung/donerunnables/RunnableCompletionCheckerWithCompletableFuture.java
+46
View File
@@ -0,0 +1,46 @@
package com.baeldung.donerunnables;
import java.util.List;
import java.util.concurrent.CompletableFuture;
import java.util.stream.Collectors;
import java.util.stream.IntStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class RunnableCompletionCheckerWithCompletableFuture {
private static final Logger LOGGER = LoggerFactory.getLogger(RunnableCompletionCheckerWithCompletableFuture.class);
private static final int NUMBER_OF_RUNNABLES = 5;
private static final int PAUSE_MILLIS = 1000;
private static Runnable RUNNABLE = () -> {
try {
LOGGER.info("launching runnable");
Thread.sleep(PAUSE_MILLIS);
} catch (InterruptedException e) {
}
};
public static void main(String args[]) throws InterruptedException {
List<Runnable> runnables = IntStream.range(0, NUMBER_OF_RUNNABLES)
.mapToObj(x -> RUNNABLE)
.collect(Collectors.toList());
CompletableFuture<?>[] completableFutures = runAsynchronousTasks(runnables);
LOGGER.info("Right after the creation of the completable future array, every completable future is done: {}", isEveryCompletableFutureDone(completableFutures));
Thread.sleep((NUMBER_OF_RUNNABLES + 1) * PAUSE_MILLIS);
LOGGER.info("After {} seconds, every completable future is done: {}", NUMBER_OF_RUNNABLES + 1, isEveryCompletableFutureDone(completableFutures));
}
public static CompletableFuture<?>[] runAsynchronousTasks(List<Runnable> runnables) {
return runnables.stream()
.map(CompletableFuture::runAsync)
.toArray(CompletableFuture<?>[]::new);
}
public static boolean isEveryCompletableFutureDone(CompletableFuture<?>[] completableFutures) {
return CompletableFuture.allOf(completableFutures)
.isDone();
}
}
core-java-modules/core-java-concurrency-2/src/main/java/com/baeldung/donerunnables/RunnableCompletionCheckerWithThreadPoolExecutor.java
+51
View File
@@ -0,0 +1,51 @@
package com.baeldung.donerunnables;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.stream.Collectors;
import java.util.stream.IntStream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class RunnableCompletionCheckerWithThreadPoolExecutor {
private static final Logger LOGGER = LoggerFactory.getLogger(RunnableCompletionCheckerWithCompletableFuture.class);
private static final int NUMBER_OF_RUNNABLES = 5;
private static final int PAUSE_MILLIS = 1000;
private static final int NUMBER_OF_THREADS = 5;
private static Runnable RUNNABLE = () -> {
try {
LOGGER.info("launching runnable");
Thread.sleep(PAUSE_MILLIS);
} catch (InterruptedException e) {
}
};
public static void main(String args[]) throws InterruptedException {
List<Runnable> runnables = IntStream.range(0, NUMBER_OF_RUNNABLES)
.mapToObj(x -> RUNNABLE)
.collect(Collectors.toList());
ThreadPoolExecutor executor = createThreadPoolExecutor(runnables);
executor.shutdown();
LOGGER.info("After a timeout of 0 seconds, every Runnable is done: {}", isEveryRunnableDone(executor, 0));
Thread.sleep(100);
LOGGER.info("After a timeout of 100 milliseconds, every Runnable is done: {}", isEveryRunnableDone(executor, 100));
Thread.sleep(2000);
LOGGER.info("After a timeout of 2 seconds, every Runnable is done: {}", isEveryRunnableDone(executor, 1500));
}
public static ThreadPoolExecutor createThreadPoolExecutor(List<Runnable> runnables) {
ThreadPoolExecutor executor = (ThreadPoolExecutor) Executors.newFixedThreadPool(NUMBER_OF_THREADS);
runnables.forEach(executor::execute);
return executor;
}
public static boolean isEveryRunnableDone(ThreadPoolExecutor executor, int timeout) throws InterruptedException {
return executor.awaitTermination(timeout, TimeUnit.MILLISECONDS);
}
}
core-java-modules/core-java-concurrency-advanced-4/README.md
+1
View File
@@ -9,3 +9,4 @@
- [Differences Between set() and lazySet() in Java Atomic Variables](https://www.baeldung.com/java-atomic-set-vs-lazyset)
- [Volatile vs. Atomic Variables in Java](https://www.baeldung.com/java-volatile-vs-atomic)
- [What Is “Locked Ownable Synchronizers” in Thread Dump?](https://www.baeldung.com/locked-ownable-synchronizers)
- [Understanding java.lang.Thread.State: WAITING (parking)](https://www.baeldung.com/java-lang-thread-state-waiting-parking)

Some files were not shown because too many files have changed in this diff Show More