diff --git a/recursion-print/src/main/java/com/bvn13/example/recursion/print/RecursionPrint.java b/recursion-print/src/main/java/com/bvn13/example/recursion/print/RecursionPrint.java
new file mode 100644
index 0000000..be7a671
--- /dev/null
+++ b/recursion-print/src/main/java/com/bvn13/example/recursion/print/RecursionPrint.java
@@ -0,0 +1,23 @@
+package com.bvn13.example.recursion.print;
+
+/**
+ * @author bvn13
+ * @since 21.09.2019
+ */
+public class RecursionPrint {
+
+ public static void main(String... args) {
+
+ long n = 20;
+
+ boolean result = printIt(1, n);
+
+ }
+
+ private static boolean printIt(long x, long n) {
+ System.out.println(x);
+
+ return String.valueOf(x).equals(String.valueOf(n)) || printIt(x+1, n);
+ }
+
+}
diff --git a/springboot2-request-logger/.gitignore b/springboot2-request-logger/.gitignore
new file mode 100644
index 0000000..6c01878
--- /dev/null
+++ b/springboot2-request-logger/.gitignore
@@ -0,0 +1,32 @@
+HELP.md
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**
+!**/src/test/**
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
diff --git a/springboot2-request-logger/README.md b/springboot2-request-logger/README.md
new file mode 100644
index 0000000..5a225b5
--- /dev/null
+++ b/springboot2-request-logger/README.md
@@ -0,0 +1,64 @@
+# How to log every Request in SpringBoot
+
+## Prerequesites
+
+Imagine we have an web SpringBoot application containing a [Controller](./src/main/java/com/bvn13/example/springboot/springrequestlogger/controllers/FirstController.java).
+It returns a template [index](/src/main/resources/templates/index.html) containing two links: on [css file](./src/main/resources/static/test.css) and on [js file](./src/main/resources/static/test.js).
+
+So we want to log every request from client while opening `index.html`:
+1. `index.html`
+2. `test.css`
+3. `test.js`
+
+## Enabling logging
+
+We must set up the logging of our classes. Take a look at example of [logback-spring.xml](./src/main/resources/logback-spring.xml).
+
+## Build a Filter
+
+Every Spring Web application have a chain on different filters. Every request flows through this filter chain before getting a controller.
+
+So we can implement a [logging filter](./src/main/java/com/bvn13/example/springboot/springrequestlogger/filters/RequestLoggingFilter.java) and put it into Spring Filter Chain to achieve our goal.
+
+```java
+@Slf4j
+@Component
+public class RequestLoggingFilter extends OncePerRequestFilter {
+ @Override
+ protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
+ log.debug(
+ String.format("FILTERED URL: %s", request.getRequestURI())
+ );
+
+ //continue filtering
+ filterChain.doFilter(request, response);
+ }
+}
+```
+
+Using `@Slf4j` annotation get us to decrease boilerplate code to have a logger in a class.
+
+We must annotate our class with `@Component` annotation to make SpringBoot to instantiate this class as spring bean in Singleton scope.
+
+Our class extends `OncePerRequestFilter` abstract class so every request goes through our filter only once.
+
+And we are able to log anything regarding the request inside `doFilterInternal` method.
+
+### Result
+
+You may run [testControllerLoggingWithFilter](./src/test/java/com/bvn13/example/springboot/springrequestlogger/SpringrequestloggerApplicationTests.java) to see the result
+
+```java
+ @Test(expected = HttpClientErrorException.NotFound.class)
+ public void testControllerLoggingWithFilter() {
+ restTemplate.getForObject("http://localhost:"+port+"/", String.class);
+ restTemplate.getForObject("http://localhost:"+port+"/test.js", String.class);
+ restTemplate.getForObject("http://localhost:"+port+"/test.css", String.class);
+ restTemplate.getForObject("http://localhost:"+port+"/does-not-exist.file", String.class);
+ }
+```
+
+![](./img/2019-09-29_21-09.png)
+
+So our goal is achieved. We can see all files we request and not existing file too.
+
diff --git a/springboot2-request-logger/build.gradle b/springboot2-request-logger/build.gradle
new file mode 100644
index 0000000..57af482
--- /dev/null
+++ b/springboot2-request-logger/build.gradle
@@ -0,0 +1,28 @@
+plugins {
+ id 'org.springframework.boot' version '2.1.8.RELEASE'
+ id 'io.spring.dependency-management' version '1.0.8.RELEASE'
+ id 'java'
+}
+
+group = 'com.bvn13.example.springboot'
+version = '0.0.1-SNAPSHOT'
+sourceCompatibility = '1.8'
+
+
+configurations {
+ compileOnly {
+ extendsFrom annotationProcessor
+ }
+}
+
+repositories {
+ mavenCentral()
+}
+
+dependencies {
+ implementation 'org.springframework.boot:spring-boot-starter-thymeleaf'
+ implementation 'org.springframework.boot:spring-boot-starter-web'
+ compileOnly 'org.projectlombok:lombok'
+ annotationProcessor 'org.projectlombok:lombok'
+ testImplementation 'org.springframework.boot:spring-boot-starter-test'
+}
diff --git a/springboot2-request-logger/gradle/wrapper/gradle-wrapper.jar b/springboot2-request-logger/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..5c2d1cf
Binary files /dev/null and b/springboot2-request-logger/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/springboot2-request-logger/gradle/wrapper/gradle-wrapper.properties b/springboot2-request-logger/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..7c4388a
--- /dev/null
+++ b/springboot2-request-logger/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-5.6.2-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/springboot2-request-logger/gradlew b/springboot2-request-logger/gradlew
new file mode 100755
index 0000000..5ce4a33
--- /dev/null
+++ b/springboot2-request-logger/gradlew
@@ -0,0 +1,188 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed 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.
+#
+
+##############################################################################
+##
+## Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ]; do
+ ls=$(ls -ld "$PRG")
+ link=$(expr "$ls" : '.*-> \(.*\)$')
+ if expr "$link" : '/.*' >/dev/null; then
+ PRG="$link"
+ else
+ PRG=$(dirname "$PRG")"/$link"
+ fi
+done
+SAVED="$(pwd)"
+cd "$(dirname \"$PRG\")/" >/dev/null
+APP_HOME="$(pwd -P)"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=$(basename "$0")
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn() {
+ echo "$*"
+}
+
+die() {
+ echo
+ echo "$*"
+ echo
+ exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "$(uname)" in
+CYGWIN*)
+ cygwin=true
+ ;;
+Darwin*)
+ darwin=true
+ ;;
+MINGW*)
+ msys=true
+ ;;
+NONSTOP*)
+ nonstop=true
+ ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ]; then
+ if [ -x "$JAVA_HOME/jre/sh/java" ]; then
+ # IBM's JDK on AIX uses strange locations for the executables
+ JAVACMD="$JAVA_HOME/jre/sh/java"
+ else
+ JAVACMD="$JAVA_HOME/bin/java"
+ fi
+ if [ ! -x "$JAVACMD" ]; then
+ die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+ fi
+else
+ JAVACMD="java"
+ which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ]; then
+ MAX_FD_LIMIT=$(ulimit -H -n)
+ if [ $? -eq 0 ]; then
+ if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ]; then
+ MAX_FD="$MAX_FD_LIMIT"
+ fi
+ ulimit -n $MAX_FD
+ if [ $? -ne 0 ]; then
+ warn "Could not set maximum file descriptor limit: $MAX_FD"
+ fi
+ else
+ warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+ fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+ GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ]; then
+ APP_HOME=$(cygpath --path --mixed "$APP_HOME")
+ CLASSPATH=$(cygpath --path --mixed "$CLASSPATH")
+ JAVACMD=$(cygpath --unix "$JAVACMD")
+
+ # We build the pattern for arguments to be converted via cygpath
+ ROOTDIRSRAW=$(find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null)
+ SEP=""
+ for dir in $ROOTDIRSRAW; do
+ ROOTDIRS="$ROOTDIRS$SEP$dir"
+ SEP="|"
+ done
+ OURCYGPATTERN="(^($ROOTDIRS))"
+ # Add a user-defined pattern to the cygpath arguments
+ if [ "$GRADLE_CYGPATTERN" != "" ]; then
+ OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+ fi
+ # Now convert the arguments - kludge to limit ourselves to /bin/sh
+ i=0
+ for arg in "$@"; do
+ CHECK=$(echo "$arg" | egrep -c "$OURCYGPATTERN" -)
+ CHECK2=$(echo "$arg" | egrep -c "^-") ### Determine if an option
+
+ if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ]; then ### Added a condition
+ eval $(echo args$i)=$(cygpath --path --ignore --mixed "$arg")
+ else
+ eval $(echo args$i)="\"$arg\""
+ fi
+ i=$((i + 1))
+ done
+ case $i in
+ 0) set -- ;;
+ 1) set -- "$args0" ;;
+ 2) set -- "$args0" "$args1" ;;
+ 3) set -- "$args0" "$args1" "$args2" ;;
+ 4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+ 5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+ 6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+ 7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+ 8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+ 9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+ esac
+fi
+
+# Escape application args
+save() {
+ for i; do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/"; done
+ echo " "
+}
+APP_ARGS=$(save "$@")
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+# by default we should be in the correct project dir, but when run from Finder on Mac, the cwd is wrong
+if [ "$(uname)" = "Darwin" ] && [ "$HOME" = "$PWD" ]; then
+ cd "$(dirname "$0")"
+fi
+
+exec "$JAVACMD" "$@"
diff --git a/springboot2-request-logger/gradlew.bat b/springboot2-request-logger/gradlew.bat
new file mode 100644
index 0000000..9618d8d
--- /dev/null
+++ b/springboot2-request-logger/gradlew.bat
@@ -0,0 +1,100 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem 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, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/springboot2-request-logger/img/2019-09-29_21-09.png b/springboot2-request-logger/img/2019-09-29_21-09.png
new file mode 100644
index 0000000..f141180
Binary files /dev/null and b/springboot2-request-logger/img/2019-09-29_21-09.png differ
diff --git a/springboot2-request-logger/settings.gradle b/springboot2-request-logger/settings.gradle
new file mode 100644
index 0000000..7e3dd44
--- /dev/null
+++ b/springboot2-request-logger/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'springboot2-request-logger'
diff --git a/springboot2-request-logger/src/main/java/com/bvn13/example/springboot/springrequestlogger/SpringrequestloggerApplication.java b/springboot2-request-logger/src/main/java/com/bvn13/example/springboot/springrequestlogger/SpringrequestloggerApplication.java
new file mode 100644
index 0000000..e7beb68
--- /dev/null
+++ b/springboot2-request-logger/src/main/java/com/bvn13/example/springboot/springrequestlogger/SpringrequestloggerApplication.java
@@ -0,0 +1,13 @@
+package com.bvn13.example.springboot.springrequestlogger;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class SpringrequestloggerApplication {
+
+ public static void main(String[] args) {
+ SpringApplication.run(SpringrequestloggerApplication.class, args);
+ }
+
+}
diff --git a/springboot2-request-logger/src/main/java/com/bvn13/example/springboot/springrequestlogger/controllers/FirstController.java b/springboot2-request-logger/src/main/java/com/bvn13/example/springboot/springrequestlogger/controllers/FirstController.java
new file mode 100644
index 0000000..09f937f
--- /dev/null
+++ b/springboot2-request-logger/src/main/java/com/bvn13/example/springboot/springrequestlogger/controllers/FirstController.java
@@ -0,0 +1,26 @@
+package com.bvn13.example.springboot.springrequestlogger.controllers;
+
+import org.springframework.stereotype.Controller;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+
+/**
+ * @author bvn13
+ * @since 29.09.2019
+ */
+@Controller
+@RequestMapping(value = "/first")
+public class FirstController {
+
+ @GetMapping
+ public String getFirst() {
+ return "index";
+ }
+
+ @PostMapping
+ public String postFirst() {
+ return "redirect:/";
+ }
+
+}
diff --git a/springboot2-request-logger/src/main/java/com/bvn13/example/springboot/springrequestlogger/filters/RequestLoggingFilter.java b/springboot2-request-logger/src/main/java/com/bvn13/example/springboot/springrequestlogger/filters/RequestLoggingFilter.java
new file mode 100644
index 0000000..065a0d0
--- /dev/null
+++ b/springboot2-request-logger/src/main/java/com/bvn13/example/springboot/springrequestlogger/filters/RequestLoggingFilter.java
@@ -0,0 +1,29 @@
+package com.bvn13.example.springboot.springrequestlogger.filters;
+
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.stereotype.Component;
+import org.springframework.web.filter.OncePerRequestFilter;
+
+import javax.servlet.FilterChain;
+import javax.servlet.ServletException;
+import javax.servlet.http.HttpServletRequest;
+import javax.servlet.http.HttpServletResponse;
+import java.io.IOException;
+
+/**
+ * @author bvn13
+ * @since 29.09.2019
+ */
+@Slf4j
+@Component
+public class RequestLoggingFilter extends OncePerRequestFilter {
+ @Override
+ protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
+ log.debug(
+ String.format("FILTERED URL: %s", request.getRequestURI())
+ );
+
+ //continue filtering
+ filterChain.doFilter(request, response);
+ }
+}
diff --git a/springboot2-request-logger/src/main/resources/application.properties b/springboot2-request-logger/src/main/resources/application.properties
new file mode 100644
index 0000000..8b13789
--- /dev/null
+++ b/springboot2-request-logger/src/main/resources/application.properties
@@ -0,0 +1 @@
+
diff --git a/springboot2-request-logger/src/main/resources/logback-spring.xml b/springboot2-request-logger/src/main/resources/logback-spring.xml
new file mode 100644
index 0000000..a3ad456
--- /dev/null
+++ b/springboot2-request-logger/src/main/resources/logback-spring.xml
@@ -0,0 +1,23 @@
+
+