designpatterns demo

README.md

+# springboot-resilience4j
\ No newline at end of file

catalog-service/.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/

catalog-service/.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

catalog-service/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%

catalog-service/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>2.6.3</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>com.javatechie</groupId>
+	<artifactId>catalog-service</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>order-service</name>
+	<description>order microservice</description>
+	<properties>
+		<java.version>1.8</java.version>
+	</properties>
+	<dependencies>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-data-jpa</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-web</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>com.h2database</groupId>
+			<artifactId>h2</artifactId>
+			<scope>runtime</scope>
+		</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>

catalog-service/src/main/java/com/nisum/cs/CatalogServiceApplication.java

+package com.nisum.cs;
+
+import com.nisum.cs.entity.Order;
+import com.nisum.cs.repository.OrderRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.web.bind.annotation.*;
+
+import javax.annotation.PostConstruct;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+@SpringBootApplication
+@RestController
+@RequestMapping("/orders")
+public class CatalogServiceApplication {
+
+    @Autowired
+    private OrderRepository orderRepository;
+
+    @PostConstruct
+    public void initOrdersTable() {
+        orderRepository.saveAll(Stream.of(
+                new Order("mobile", "electronics", "white", 20000),
+                new Order("T-Shirt", "clothes", "black", 999),
+                new Order("Jeans", "clothes", "blue", 1999),
+                new Order("Laptop", "electronics", "gray", 50000),
+                new Order("digital watch", "electronics", "black", 2500),
+                new Order("Fan", "electronics", "black", 50000),
+                new Order("Pizza", "food", "white", 2000),
+                new Order("Burger", "food", "black", 999),
+                new Order("Pasta", "food", "blue", 199)
+        ).
+                collect(Collectors.toList()));
+    }
+
+    @GetMapping
+    public List<Order> getOrders() {
+        return orderRepository.findAll();
+    }
+
+    @GetMapping("/{category}")
+    public List<Order> getOrdersByCategory(@PathVariable String category) {
+        return orderRepository.findByCategory(category);
+    }
+
+    public static void main(String[] args) {
+        SpringApplication.run(CatalogServiceApplication.class, args);
+    }
+
+}

catalog-service/src/main/java/com/nisum/cs/entity/Order.java

+package com.nisum.cs.entity;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "ORDERS_TBL")
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class Order {
+
+    @Id
+    @GeneratedValue
+    private int id;
+    private String name;
+    private String category;
+    private String color;
+    private double price;
+
+    public Order(String name, String category, String color, double price) {
+        this.name = name;
+        this.category = category;
+        this.color = color;
+        this.price = price;
+    }
+}

catalog-service/src/main/java/com/nisum/cs/repository/OrderRepository.java

+package com.nisum.cs.repository;
+
+import com.nisum.cs.entity.Order;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.List;
+
+public interface OrderRepository extends JpaRepository<Order,Integer> {
+
+    List<Order> findByCategory(String category);
+
+
+}

catalog-service/src/main/resources/application.properties

+

catalog-service/src/main/resources/application.yml

+server:
+  port: 9393
+
+spring:
+  datasource:
+    url: jdbc:h2:mem:testdb
+  h2:
+    console:
+      enabled: true
+      path: /h2
\ No newline at end of file

catalog-service/src/test/java/com/nisum/cs/OrderServiceApplicationTests.java

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

user-service/.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/

user-service/.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

user-service/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%

user-service/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>2.6.3</version>
+		<relativePath/> <!-- lookup parent from repository -->
+	</parent>
+	<groupId>com.javatechie</groupId>
+	<artifactId>user-service</artifactId>
+	<version>0.0.1-SNAPSHOT</version>
+	<name>user-service</name>
+	<description>order microservice</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>
+
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-actuator</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-aop</artifactId>
+		</dependency>
+		<dependency>
+			<groupId>io.github.resilience4j</groupId>
+			<artifactId>resilience4j-spring-boot2</artifactId>
+			<version>1.5.0</version>
+		</dependency>
+		<dependency>
+		<groupId>redis.clients</groupId>
+		<artifactId>jedis</artifactId>
+		<version>3.3.0</version>
+		</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>

user-service/src/main/java/com/nisum/us/UserServiceApplication.java

+package com.nisum.us;
+
+import com.nisum.us.dto.OrderDTO;
+import io.github.resilience4j.bulkhead.annotation.Bulkhead;
+import io.github.resilience4j.circuitbreaker.annotation.CircuitBreaker;
+import io.github.resilience4j.ratelimiter.annotation.RateLimiter;
+import io.github.resilience4j.retry.annotation.Retry;
+import io.github.resilience4j.timelimiter.annotation.TimeLimiter;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cache.annotation.CacheEvict;
+import org.springframework.cache.annotation.Cacheable;
+import org.springframework.cache.annotation.Caching;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Lazy;
+import org.springframework.web.bind.annotation.*;
+import org.springframework.web.client.RestTemplate;
+
+import java.util.ArrayList;
+import java.util.Date;
+import java.util.List;
+import java.util.stream.Collectors;
+import java.util.stream.IntStream;
+import java.util.stream.Stream;
+
+@SpringBootApplication
+@RestController
+@RequestMapping("/user-service")
+public class UserServiceApplication {
+
+    @Autowired
+    @Lazy
+    private RestTemplate restTemplate;
+
+    public static final String USER_SERVICE = "userService";
+
+    private static final String BASEURL = "http://localhost:9393/orders";
+
+    private int attempt = 1;
+
+    @GetMapping
+    public List<OrderDTO> testMethod() {
+        return restTemplate.getForObject(BASEURL, ArrayList.class);
+    }
+
+    @GetMapping("/displayOrders")
+    @CircuitBreaker(name = USER_SERVICE, fallbackMethod = "getAllAvailableProducts")
+    public List<OrderDTO> displayOrders(@RequestParam("category") String category) {
+        String url = category == null ? BASEURL : BASEURL + "/" + category;
+        return restTemplate.getForObject(url, ArrayList.class);
+    }
+
+    @GetMapping("/retryDisplayOrders")
+    @Retry(name = USER_SERVICE, fallbackMethod = "getAllAvailableProducts")
+    public List<OrderDTO> displayOrders2(@RequestParam("category") String category) {
+        String url = category == null ? BASEURL : BASEURL + "/" + category;
+        System.out.println("retry method called " + attempt++ + " times " + " at " + new Date());
+        return restTemplate.getForObject(url, ArrayList.class);
+    }
+
+    @GetMapping("/bulkHeadDisplayOrders")
+    @Bulkhead(name = USER_SERVICE, fallbackMethod = "getAllAvailableProducts")
+    public List<OrderDTO> displayOrders3(@RequestParam("category") String category) {
+        String url = category == null ? BASEURL : BASEURL + "/" + category;
+        System.out.println("bulkhead method called at " + new Date());
+        try {
+            Thread.sleep(4000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        return restTemplate.getForObject(url, ArrayList.class);
+    }
+
+    @GetMapping("/rateLimiterDisplayOrders")
+    @RateLimiter(name = USER_SERVICE, fallbackMethod = "getAllAvailableProducts")
+    public List<OrderDTO> displayOrders4(@RequestParam("category") String category) {
+        String url = category == null ? BASEURL : BASEURL + "/" + category;
+        return restTemplate.getForObject(url, ArrayList.class);
+    }
+
+    @GetMapping("/timeLimitDisplayOrders")
+    @TimeLimiter(name = USER_SERVICE)
+    public List<OrderDTO> displayOrders5(@RequestParam("category") String category) {
+        String url = category == null ? BASEURL : BASEURL + "/" + category;
+        System.out.println("bulkhead method called at " + new Date());
+        try {
+            Thread.sleep(4000);
+        } catch (InterruptedException e) {
+            e.printStackTrace();
+        }
+        return restTemplate.getForObject(url, ArrayList.class);
+    }
+
+    @GetMapping("/aggregate")
+    public List<OrderDTO> displayOrders6(@RequestParam("category") String category) {
+        String url = category == null ? BASEURL : BASEURL + "/electronics"  ;
+        ArrayList<OrderDTO> forObject1 = restTemplate.getForObject(url, ArrayList.class);
+        url = category == null ? BASEURL : BASEURL + "/clothes";
+        ArrayList<OrderDTO> forObject = restTemplate.getForObject(url, ArrayList.class);
+        List<OrderDTO> aggList = new ArrayList<>();
+        aggList.addAll(forObject);
+        aggList.addAll(forObject1);
+        return aggList;
+    }
+
+    public List<OrderDTO> getAllAvailableProducts(Exception e) {
+        return Stream.of(
+                new OrderDTO(119, "dummy11", "electronics", "white", 45000),
+                new OrderDTO(345, "dummy12", "electronics", "black", 7000),
+                new OrderDTO(475, "dummy13", "electronics", "black", 13000),
+                new OrderDTO(574, "dummy14", "foot wear", "black & white", 4600),
+                new OrderDTO(678, "dummy15", "kitchen", "blue", 999),
+                new OrderDTO(532, "dummy16", "kitchen", "gray", 745)
+        ).collect(Collectors.toList());
+    }
+
+    @GetMapping("/{id}")
+    @Cacheable(key = "#id",value = "OrderDTO",unless = "#result.price > 1000")
+    public OrderDTO findProduct(@PathVariable int id) {
+        return null;
+    }
+
+    @DeleteMapping("/{id}")
+    @CacheEvict(key = "#id",value = "Product")
+    public String remove(@PathVariable int id) {
+        return null;
+    }
+
+    public static void main(String[] args) {
+
+        SpringApplication.run(UserServiceApplication.class, args);
+
+        //bulkhead demo
+//        int i = 1;
+//        IntStream.range(i, 10).parallel().forEach(t -> {
+//            new RestTemplate().getForObject("http://localhost:9191/user-service/bulkHeadDisplayOrders?category=", String.class);
+//        });
+    }
+
+    @Bean
+    public RestTemplate restTemplate() {
+        return new RestTemplate();
+    }
+}

user-service/src/main/java/com/nisum/us/dto/OrderDTO.java

+package com.nisum.us.dto;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+public class OrderDTO {
+    private int id;
+    private String name;
+    private String category;
+    private String color;
+    private double price;
+}

user-service/src/main/resources/application.properties

+server.port=9191

user-service/src/main/resources/application.yml

+management:
+  health:
+    circuitbreakers:
+      enabled: true
+  endpoints:
+    web:
+      exposure:
+        include: health
+  endpoint:
+    health:
+      show-details: always
+
+
+resilience4j:
+  circuitbreaker:
+    instances:
+      userService:
+        registerHealthIndicator: true
+        eventConsumerBufferSize: 10
+        failureRateThreshold: 50
+        minimumNumberOfCalls: 5
+        automaticTransitionFromOpenToHalfOpenEnabled: true
+        waitDurationInOpenState: 5s
+        permittedNumberOfCallsInHalfOpenState: 3
+        slidingWindowSize: 10
+        slidingWindowType: COUNT_BASED
+
+
+  retry:
+    instances:
+      userService:
+        maxRetryAttempts: 5
+        waitDuration: 6s
+
+
+  bulkhead:
+    instances:
+      userService:
+        maxWaitDuration: 3000
+        maxConcurrentCalls: 4
+
+  ratelimiter:
+    instances:
+      userService:
+        limitForPeriod: 2
+        limitRefreshPeriod: 4s
+        timeoutDuration: 10s
+        registerHealthIndicator: true
+        eventConsumerBufferSize: 100
+
+  timelimiter:
+    instances:
+      userService:
+        timeoutDuration: 10s
+        cancelRunningFuture: true
+
+
+
+
+
+
+
+
+

user-service/src/test/java/com/nisum/us/UserServiceApplicationTests.java

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