collection examples

.gitignore

+HELP.md
+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/

.mvn/wrapper/maven-wrapper.properties

+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+distributionUrl=https://repo.maven.apache.org/maven2/org/apache/maven/apache-maven/3.8.7/apache-maven-3.8.7-bin.zip
+wrapperUrl=https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.1.1/maven-wrapper-3.1.1.jar

mvnw.cmd

+@REM ----------------------------------------------------------------------------
+@REM Licensed to the Apache Software Foundation (ASF) under one
+@REM or more contributor license agreements.  See the NOTICE file
+@REM distributed with this work for additional information
+@REM regarding copyright ownership.  The ASF licenses this file
+@REM to you under the Apache License, Version 2.0 (the
+@REM "License"); you may not use this file except in compliance
+@REM with the License.  You may obtain a copy of the License at
+@REM
+@REM    https://www.apache.org/licenses/LICENSE-2.0
+@REM
+@REM Unless required by applicable law or agreed to in writing,
+@REM software distributed under the License is distributed on an
+@REM "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+@REM KIND, either express or implied.  See the License for the
+@REM specific language governing permissions and limitations
+@REM under the License.
+@REM ----------------------------------------------------------------------------
+
+@REM ----------------------------------------------------------------------------
+@REM Maven Start Up Batch script
+@REM
+@REM Required ENV vars:
+@REM JAVA_HOME - location of a JDK home dir
+@REM
+@REM Optional ENV vars
+@REM M2_HOME - location of maven2's installed home dir
+@REM MAVEN_BATCH_ECHO - set to 'on' to enable the echoing of the batch commands
+@REM MAVEN_BATCH_PAUSE - set to 'on' to wait for a keystroke before ending
+@REM MAVEN_OPTS - parameters passed to the Java VM when running Maven
+@REM     e.g. to debug Maven itself, use
+@REM set MAVEN_OPTS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=8000
+@REM MAVEN_SKIP_RC - flag to disable loading of mavenrc files
+@REM ----------------------------------------------------------------------------
+
+@REM Begin all REM lines with '@' in case MAVEN_BATCH_ECHO is 'on'
+@echo off
+@REM set title of command window
+title %0
+@REM enable echoing by setting MAVEN_BATCH_ECHO to 'on'
+@if "%MAVEN_BATCH_ECHO%" == "on"  echo %MAVEN_BATCH_ECHO%
+
+@REM set %HOME% to equivalent of $HOME
+if "%HOME%" == "" (set "HOME=%HOMEDRIVE%%HOMEPATH%")
+
+@REM Execute a user defined script before this one
+if not "%MAVEN_SKIP_RC%" == "" goto skipRcPre
+@REM check for pre script, once with legacy .bat ending and once with .cmd ending
+if exist "%USERPROFILE%\mavenrc_pre.bat" call "%USERPROFILE%\mavenrc_pre.bat" %*
+if exist "%USERPROFILE%\mavenrc_pre.cmd" call "%USERPROFILE%\mavenrc_pre.cmd" %*
+:skipRcPre
+
+@setlocal
+
+set ERROR_CODE=0
+
+@REM To isolate internal variables from possible post scripts, we use another setlocal
+@setlocal
+
+@REM ==== START VALIDATION ====
+if not "%JAVA_HOME%" == "" goto OkJHome
+
+echo.
+echo Error: JAVA_HOME not found in your environment. >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+:OkJHome
+if exist "%JAVA_HOME%\bin\java.exe" goto init
+
+echo.
+echo Error: JAVA_HOME is set to an invalid directory. >&2
+echo JAVA_HOME = "%JAVA_HOME%" >&2
+echo Please set the JAVA_HOME variable in your environment to match the >&2
+echo location of your Java installation. >&2
+echo.
+goto error
+
+@REM ==== END VALIDATION ====
+
+:init
+
+@REM Find the project base dir, i.e. the directory that contains the folder ".mvn".
+@REM Fallback to current working directory if not found.
+
+set MAVEN_PROJECTBASEDIR=%MAVEN_BASEDIR%
+IF NOT "%MAVEN_PROJECTBASEDIR%"=="" goto endDetectBaseDir
+
+set EXEC_DIR=%CD%
+set WDIR=%EXEC_DIR%
+:findBaseDir
+IF EXIST "%WDIR%"\.mvn goto baseDirFound
+cd ..
+IF "%WDIR%"=="%CD%" goto baseDirNotFound
+set WDIR=%CD%
+goto findBaseDir
+
+:baseDirFound
+set MAVEN_PROJECTBASEDIR=%WDIR%
+cd "%EXEC_DIR%"
+goto endDetectBaseDir
+
+:baseDirNotFound
+set MAVEN_PROJECTBASEDIR=%EXEC_DIR%
+cd "%EXEC_DIR%"
+
+:endDetectBaseDir
+
+IF NOT EXIST "%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config" goto endReadAdditionalConfig
+
+@setlocal EnableExtensions EnableDelayedExpansion
+for /F "usebackq delims=" %%a in ("%MAVEN_PROJECTBASEDIR%\.mvn\jvm.config") do set JVM_CONFIG_MAVEN_PROPS=!JVM_CONFIG_MAVEN_PROPS! %%a
+@endlocal & set JVM_CONFIG_MAVEN_PROPS=%JVM_CONFIG_MAVEN_PROPS%
+
+:endReadAdditionalConfig
+
+SET MAVEN_JAVA_EXE="%JAVA_HOME%\bin\java.exe"
+set WRAPPER_JAR="%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.jar"
+set WRAPPER_LAUNCHER=org.apache.maven.wrapper.MavenWrapperMain
+
+set DOWNLOAD_URL="https://repo.maven.apache.org/maven2/org/apache/maven/wrapper/maven-wrapper/3.1.0/maven-wrapper-3.1.0.jar"
+
+FOR /F "usebackq tokens=1,2 delims==" %%A IN ("%MAVEN_PROJECTBASEDIR%\.mvn\wrapper\maven-wrapper.properties") DO (
+    IF "%%A"=="wrapperUrl" SET DOWNLOAD_URL=%%B
+)
+
+@REM Extension to allow automatically downloading the maven-wrapper.jar from Maven-central
+@REM This allows using the maven wrapper in projects that prohibit checking in binary data.
+if exist %WRAPPER_JAR% (
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Found %WRAPPER_JAR%
+    )
+) else (
+    if not "%MVNW_REPOURL%" == "" (
+        SET DOWNLOAD_URL="%MVNW_REPOURL%/org/apache/maven/wrapper/maven-wrapper/3.1.0/maven-wrapper-3.1.0.jar"
+    )
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Couldn't find %WRAPPER_JAR%, downloading it ...
+        echo Downloading from: %DOWNLOAD_URL%
+    )
+
+    powershell -Command "&{"^
+		"$webclient = new-object System.Net.WebClient;"^
+		"if (-not ([string]::IsNullOrEmpty('%MVNW_USERNAME%') -and [string]::IsNullOrEmpty('%MVNW_PASSWORD%'))) {"^
+		"$webclient.Credentials = new-object System.Net.NetworkCredential('%MVNW_USERNAME%', '%MVNW_PASSWORD%');"^
+		"}"^
+		"[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12; $webclient.DownloadFile('%DOWNLOAD_URL%', '%WRAPPER_JAR%')"^
+		"}"
+    if "%MVNW_VERBOSE%" == "true" (
+        echo Finished downloading %WRAPPER_JAR%
+    )
+)
+@REM End of extension
+
+@REM Provide a "standardized" way to retrieve the CLI args that will
+@REM work with both Windows and non-Windows executions.
+set MAVEN_CMD_LINE_ARGS=%*
+
+%MAVEN_JAVA_EXE% ^
+  %JVM_CONFIG_MAVEN_PROPS% ^
+  %MAVEN_OPTS% ^
+  %MAVEN_DEBUG_OPTS% ^
+  -classpath %WRAPPER_JAR% ^
+  "-Dmaven.multiModuleProjectDirectory=%MAVEN_PROJECTBASEDIR%" ^
+  %WRAPPER_LAUNCHER% %MAVEN_CONFIG% %*
+if ERRORLEVEL 1 goto error
+goto end
+
+:error
+set ERROR_CODE=1
+
+:end
+@endlocal & set ERROR_CODE=%ERROR_CODE%
+
+if not "%MAVEN_SKIP_RC%"=="" goto skipRcPost
+@REM check for post script, once with legacy .bat ending and once with .cmd ending
+if exist "%USERPROFILE%\mavenrc_post.bat" call "%USERPROFILE%\mavenrc_post.bat"
+if exist "%USERPROFILE%\mavenrc_post.cmd" call "%USERPROFILE%\mavenrc_post.cmd"
+:skipRcPost
+
+@REM pause the script if MAVEN_BATCH_PAUSE is set to 'on'
+if "%MAVEN_BATCH_PAUSE%"=="on" pause
+
+if "%MAVEN_TERMINATE_CMD%"=="on" exit %ERROR_CODE%
+
+cmd /C exit /B %ERROR_CODE%

pom.xml

+<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
+	<modelVersion>4.0.0</modelVersion>
+	<parent>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-parent</artifactId>
+		<version>2.7.9</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>com.example</groupId>
+	<artifactId>collections</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>collections</name>
+	<description>Demo project for Spring Boot collection example</description>
+	<properties>
+		<java.version>1.8</java.version>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>org.projectlombok</groupId>
+			<artifactId>lombok</artifactId>
+			<optional>true</optional>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
+	</dependencies>
+
+	<build>
+		<plugins>
+			<plugin>
+				<groupId>org.springframework.boot</groupId>
+				<artifactId>spring-boot-maven-plugin</artifactId>
+				<configuration>
+					<excludes>
+						<exclude>
+							<groupId>org.projectlombok</groupId>
+							<artifactId>lombok</artifactId>
+						</exclude>
+					</excludes>
+				</configuration>
+			</plugin>
+		</plugins>
+	</build>
+
+</project>

src/main/java/com/example/collections/CollectionsApplication.java

+package com.example.collections;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class CollectionsApplication {
+
+	public static void main(String[] args) {
+		SpringApplication.run(CollectionsApplication.class, args);
+	}
+
+}

src/main/java/com/example/collections/list/ArrayListExample.java

+package com.example.collections.list;
+import java.util.*;
+class ArrayListExample{
+    public static void main(String args[]){
+
+        ArrayList al=new ArrayList();  // creating array list
+        al.add("Jack");                // adding elements
+        al.add("Tyler");
+        Iterator itr=al.iterator();
+        while(itr.hasNext()){
+            System.out.println(itr.next());
+        }
+    }
+}

src/main/java/com/example/collections/list/LinkedlistExample.java

+package com.example.collections.list;
+
+import java.util.*;
+public class LinkedlistExample{
+    public static void main(String args[]){
+        LinkedList<String> al=new LinkedList<String>();// creating linked list
+        al.add("sarika"); // adding elements
+        al.add("sony");
+        al.add("honey");
+        Iterator<String> itr = al.iterator();
+        while(itr.hasNext()){
+            System.out.println(itr.next());
+        }
+    }
+}

src/main/java/com/example/collections/list/StackExample.java

+package com.example.collections.list;
+import java.util.*;
+public class StackExample {
+        public static void main(String args[]){
+            Stack<String> stack = new Stack<String>();
+            stack.push("keyboard");
+            stack.push("laptop");
+            stack.push("mouse");
+            stack.push("computer");
+            stack.push("tab");
+            stack.pop();
+            Iterator<String> itr=stack.iterator();
+            while(itr.hasNext()){
+                System.out.println(itr.next());
+            }
+        }
+    }
+

src/main/java/com/example/collections/list/VectorExample.java

+package com.example.collections.list;
+import java.util.*;
+public class VectorExample {
+        public static void main(String args[]){
+            Vector<String> v=new Vector<String>();
+            v.add("sarika");
+            v.add("anjali");
+            v.add("rajesham");
+            v.add("shivasai");
+            Iterator<String> itr=v.iterator();
+            while(itr.hasNext()){
+                System.out.println(itr.next());
+            }
+        }
+    }
+

src/main/java/com/example/collections/map/ComparingKeyDo.java

+package com.example.collections.map;
+import java.util.*;
+public class ComparingKeyDo {
+    public static void main(String args[]){
+            Map<Integer,String> map=new HashMap<Integer,String>();
+            map.put(100,"sarika");
+            map.put(101,"navya");
+            map.put(102,"sri");
+            //Returns a Set view of the mappings contained in this map
+            map.entrySet()
+                    //Returns a sequential Stream with this collection as its source
+                    .stream()
+                    //Sorted according to the provided Comparator
+                    .sorted(Map.Entry.comparingByKey(Comparator.reverseOrder()))
+                    //Performs an action for each element of this stream
+                    .forEach(System.out::println);
+        }
+    }
+

src/main/java/com/example/collections/map/ComparingValueDo.java

+package com.example.collections.map;
+import java.util.*;
+public class ComparingValueDo {
+      public static void main(String args[]){
+       Map<Integer,String> map=new HashMap<Integer,String>();
+          //  SortedMap<Integer,String> map=new TreeMap<>();
+            map.put(101,"sony");
+            map.put(100,"sweety");
+            map.put(102,"honey");
+            //Returns a Set view of the mappings contained in this map
+            map.entrySet()
+                    //Returns a sequential Stream with this collection as its source
+                    .stream()
+                    //Sorted according to the provided Comparator
+                    .sorted(Map.Entry.comparingByValue(Comparator.reverseOrder()))
+                    //Performs an action for each element of this stream
+                    .forEach(System.out::println);
+        }
+    }
+

src/main/java/com/example/collections/map/MapExample.java

+package com.example.collections.map;
+import java.util.*;
+public class MapExample {
+        public static void main(String args[]){
+            Map<Integer,String> map=new HashMap<Integer,String>();
+            map.put(100,"sarika");
+            map.put(101,"sony");
+            map.put(102,"honey");
+            //Elements can traverse in any order
+            for(Map.Entry m:map.entrySet()){
+                System.out.println(m.getKey()+" "+m.getValue());
+            }
+        }
+    }
+

src/main/java/com/example/collections/queue/ArrayDeqeueExample.java

+package com.example.collections.queue;
+import java.util.*;
+public class ArrayDeqeueExample {
+        public static void main(String[] args) {
+//Creating Deque and adding elements
+            Deque<String> deque = new ArrayDeque<String>();
+            deque.add("anjali");
+            deque.add("shivasai");
+            deque.add("Rajesham");
+//Traversing elements
+            for (String str : deque) {
+                System.out.println(str);
+            }
+        }
+    }
+

src/main/java/com/example/collections/queue/QueueExample.java

+package com.example.collections.queue;
+import java.util.*;
+
+class QueueExample {
+    public static void main(String args[]) {
+        PriorityQueue<String> queue = new PriorityQueue<String>();
+        // creating priority queue
+        queue.add("sarika");
+        // adding elements
+        queue.add("sony");
+        queue.add("honey");
+        System.out.println("head:" + queue.element());
+        System.out.println("head:" + queue.peek());
+        System.out.println("iterating the queue elements:");
+        Iterator itr = queue.iterator();
+        while (itr.hasNext()) {
+            System.out.println(itr.next());
+        }
+        queue.remove();
+        queue.poll();
+        System.out.println("after removing two elements:");
+        Iterator<String> itr2 = queue.iterator();
+        while (itr2.hasNext()) {
+            System.out.println(itr2.next());
+        }
+    }
+}

src/main/java/com/example/collections/set/HashSetExample.java

+package com.example.collections.set;
+import java.util.*;
+public class HashSetExample {
+        public static void main(String args[]){
+//Creating HashSet and adding elements
+            HashSet<String> set=new HashSet<String>();
+            set.add("Ravi");
+            set.add("Vijay");
+            set.add("Ravi");
+            set.add("Ajay");
+//Traversing elements
+            Iterator<String> itr=set.iterator();
+            while(itr.hasNext()){
+                System.out.println(itr.next());
+            }
+        }
+    }
+

src/main/java/com/example/collections/set/LinkedHashsetExample.java

+package com.example.collections.set;
+import java.util.*;
+public class LinkedHashsetExample {
+
+    public static void main(String args[]){
+        LinkedHashSet<String> set=new LinkedHashSet<String>();
+        set.add("Ravi");
+        set.add("Vijay");
+        set.add("Ravi");
+        set.add("Ajay");
+        Iterator<String> itr=set.iterator();
+        while(itr.hasNext()){
+            System.out.println(itr.next());
+        }
+    }
+}

src/main/java/com/example/collections/set/TreesetExample.java

+package com.example.collections.set;
+import java.util.*;
+public class TreesetExample {
+        public static void main(String args[]){
+//Creating and adding elements
+            SortedSet<String> set=new TreeSet<String>();
+            set.add("Ravi");
+            set.add("Vijay");
+            set.add("Ravi");
+            set.add("Ajay");
+//traversing elements
+            Iterator<String> itr=set.iterator();
+            while(itr.hasNext()){
+                System.out.println(itr.next());
+            }
+        }
+    }
+

src/main/resources/application.properties

+

src/test/java/com/example/collections/CollectionsApplicationTests.java

+package com.example.collections;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.test.context.SpringBootTest;
+
+@SpringBootTest
+class CollectionsApplicationTests {
+
+	@Test
+	void contextLoads() {
+	}
+
+}