diff --git a/.gitignore b/.gitignore
index 188fae84..6e4b2269 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,7 @@
-.idea
-out
 *.iml
+.gradle
+.idea
+build
+lib
 log
-
-
-
+out
diff --git a/build.gradle b/build.gradle
new file mode 100644
index 00000000..daca46ff
--- /dev/null
+++ b/build.gradle
@@ -0,0 +1,33 @@
+plugins {
+	id 'java'
+	id 'idea'
+}
+
+group = 'ru.topjava.webapp'
+version '1.0'
+
+repositories {
+	mavenLocal()
+	mavenCentral()
+//	maven { url "http://artapp/artifactory/public/" }
+}
+
+sourceSets {
+	test.java.srcDir 'test'
+
+    main {
+        java {
+            srcDirs = ['src']
+        }
+    }
+}
+
+configurations{
+	implementation { 
+		transitive = true
+	}
+}
+
+dependencies {
+	implementation 'junit:junit:4.13.1'
+}
diff --git a/gradle/wrapper/gradle-wrapper.jar b/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 00000000..e708b1c0
Binary files /dev/null and b/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 00000000..77a56e49
--- /dev/null
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,7 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.7.1-bin.zip
+#distributionUrl=http\://artapp/artifactory/gradle-wrapper-remote-cache/distributions/gradle-6.7.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+file.encoding=utf-8
diff --git a/gradlew b/gradlew
new file mode 100644
index 00000000..3f4e36b5
--- /dev/null
+++ b/gradlew
@@ -0,0 +1,186 @@
+#!/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 "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+GRADLE_OPTS="-Dfile.encoding=utf-8"
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+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=`expr $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"
+
+exec "$JAVACMD" "$@"
diff --git a/gradlew.bat b/gradlew.bat
new file mode 100644
index 00000000..900fca17
--- /dev/null
+++ b/gradlew.bat
@@ -0,0 +1,90 @@
+@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 Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@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"
+set GRADLE_OPTS="-Dfile.encoding=utf-8"
+
+@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 execute
+
+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 execute
+
+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
+
+: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 %*
+
+: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/lesson/lesson1.md b/lesson/lesson1.md
index a1b848e6..5e077974 100644
--- a/lesson/lesson1.md
+++ b/lesson/lesson1.md
@@ -88,7 +88,7 @@ r1, r2, r3,..., rn, null, null,..., null
 <----- size ----->
 <------- storage.length (10000) ------->
 ```
-- Протестируйте вашу реализацию с помощью классов `MainArray.main()` и `MainTestArrayStorage.main()`
+- Протестируйте вашу реализацию с помощью классов `ru.topjava.webapp.MainArray.main()` и `ru.topjava.webapp.MainTestArrayStorage.main()`
 - Изучите дополнительные материалы по IntelliJ IDEA:
   - [Idea Wiki](https://github.com/JavaOPs/topjava/wiki/IDEA) ([поставьте кодировку UTF-8](https://github.com/JavaOPs/topjava/wiki/IDEA#Поставить-кодировку-utf-8), [поменяйте шрифт по умолчанию на DejaVu](https://github.com/JavaOPs/topjava/wiki/IDEA#Поменять-фонт-по-умолчанию-dejavu))
   - [Руководство пользователя IntelliJ IDEA. Отладчик](http://info.javarush.ru/idea_help/2014/01/22/Руководство-пользователя-IntelliJ-IDEA-Отладчик-.html)
diff --git a/settings.gradle b/settings.gradle
new file mode 100644
index 00000000..4e04e401
--- /dev/null
+++ b/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = "basejava"
diff --git a/src/ArrayStorage.java b/src/ArrayStorage.java
deleted file mode 100644
index 7aff0388..00000000
--- a/src/ArrayStorage.java
+++ /dev/null
@@ -1,30 +0,0 @@
-/**
- * Array based storage for Resumes
- */
-public class ArrayStorage {
-    Resume[] storage = new Resume[10000];
-
-    void clear() {
-    }
-
-    void save(Resume r) {
-    }
-
-    Resume get(String uuid) {
-        return null;
-    }
-
-    void delete(String uuid) {
-    }
-
-    /**
-     * @return array, contains only Resumes in storage (without null)
-     */
-    Resume[] getAll() {
-        return new Resume[0];
-    }
-
-    int size() {
-        return 0;
-    }
-}
diff --git a/src/MainArray.java b/src/MainArray.java
deleted file mode 100644
index b1cb33b7..00000000
--- a/src/MainArray.java
+++ /dev/null
@@ -1,71 +0,0 @@
-import java.io.BufferedReader;
-import java.io.IOException;
-import java.io.InputStreamReader;
-
-/**
- * Interactive test for ArrayStorage implementation
- * (just run, no need to understand)
- */
-public class MainArray {
-    private final static ArrayStorage ARRAY_STORAGE = new ArrayStorage();
-
-    public static void main(String[] args) throws IOException {
-        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
-        Resume r;
-        while (true) {
-            System.out.print("Введите одну из команд - (list | save uuid | delete uuid | get uuid | clear | exit): ");
-            String[] params = reader.readLine().trim().toLowerCase().split(" ");
-            if (params.length < 1 || params.length > 2) {
-                System.out.println("Неверная команда.");
-                continue;
-            }
-            String uuid = null;
-            if (params.length == 2) {
-                uuid = params[1].intern();
-            }
-            switch (params[0]) {
-                case "list":
-                    printAll();
-                    break;
-                case "size":
-                    System.out.println(ARRAY_STORAGE.size());
-                    break;
-                case "save":
-                    r = new Resume();
-                    r.uuid = uuid;
-                    ARRAY_STORAGE.save(r);
-                    printAll();
-                    break;
-                case "delete":
-                    ARRAY_STORAGE.delete(uuid);
-                    printAll();
-                    break;
-                case "get":
-                    System.out.println(ARRAY_STORAGE.get(uuid));
-                    break;
-                case "clear":
-                    ARRAY_STORAGE.clear();
-                    printAll();
-                    break;
-                case "exit":
-                    return;
-                default:
-                    System.out.println("Неверная команда.");
-                    break;
-            }
-        }
-    }
-
-    static void printAll() {
-        Resume[] all = ARRAY_STORAGE.getAll();
-        System.out.println("----------------------------");
-        if (all.length == 0) {
-            System.out.println("Empty");
-        } else {
-            for (Resume r : all) {
-                System.out.println(r);
-            }
-        }
-        System.out.println("----------------------------");
-    }
-}
\ No newline at end of file
diff --git a/src/MainTestArrayStorage.java b/src/MainTestArrayStorage.java
deleted file mode 100644
index b15b81e2..00000000
--- a/src/MainTestArrayStorage.java
+++ /dev/null
@@ -1,39 +0,0 @@
-/**
- * Test for your ArrayStorage implementation
- */
-public class MainTestArrayStorage {
-    static final ArrayStorage ARRAY_STORAGE = new ArrayStorage();
-
-    public static void main(String[] args) {
-        Resume r1 = new Resume();
-        r1.uuid = "uuid1";
-        Resume r2 = new Resume();
-        r2.uuid = "uuid2";
-        Resume r3 = new Resume();
-        r3.uuid = "uuid3";
-
-        ARRAY_STORAGE.save(r1);
-        ARRAY_STORAGE.save(r2);
-        ARRAY_STORAGE.save(r3);
-
-        System.out.println("Get r1: " + ARRAY_STORAGE.get(r1.uuid));
-        System.out.println("Size: " + ARRAY_STORAGE.size());
-
-        System.out.println("Get dummy: " + ARRAY_STORAGE.get("dummy"));
-
-        printAll();
-        ARRAY_STORAGE.delete(r1.uuid);
-        printAll();
-        ARRAY_STORAGE.clear();
-        printAll();
-
-        System.out.println("Size: " + ARRAY_STORAGE.size());
-    }
-
-    static void printAll() {
-        System.out.println("\nGet All");
-        for (Resume r : ARRAY_STORAGE.getAll()) {
-            System.out.println(r);
-        }
-    }
-}
diff --git a/src/Resume.java b/src/Resume.java
deleted file mode 100644
index 8de4e4b8..00000000
--- a/src/Resume.java
+++ /dev/null
@@ -1,13 +0,0 @@
-/**
- * Initial resume class
- */
-public class Resume {
-
-    // Unique identifier
-    String uuid;
-
-    @Override
-    public String toString() {
-        return uuid;
-    }
-}
diff --git a/src/ru/topjava/webapp/MainArray.java b/src/ru/topjava/webapp/MainArray.java
new file mode 100644
index 00000000..ff3f8cd8
--- /dev/null
+++ b/src/ru/topjava/webapp/MainArray.java
@@ -0,0 +1,107 @@
+package ru.topjava.webapp;
+
+import ru.topjava.webapp.model.Resume;
+import ru.topjava.webapp.storage.ArrayStorage;
+import ru.topjava.webapp.storage.SortedArrayStorage;
+import ru.topjava.webapp.storage.Storage;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+/**
+ * Interactive test for ArrayStorage implementation
+ * (just run, no need to understand)
+ */
+public class MainArray {
+    private static Storage arrayStorage;
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
+        Resume resume;
+        String[] params;
+        storageChoice:
+        while (true) {
+            System.out.print("Выберите тип хранилища - (sort | unsort | exit): ");
+            params = reader.readLine().trim().toLowerCase().split(" ");
+            if (params.length < 1 || params.length > 2) {
+                System.out.println("Неверная команда.");
+                continue;
+            }
+            switch (params[0]) {
+                case "sort":
+                    System.out.println("Выбранный тип хранилища: отсортированный массив.");
+                    arrayStorage = new SortedArrayStorage();
+                    break storageChoice;
+                case "unsort":
+                    System.out.println("Выбранный тип хранилища: неотсортированный массив.");
+                    arrayStorage = new ArrayStorage();
+                    break storageChoice;
+                case "exit":
+                    return;
+                default:
+                    System.out.println("Неверная команда.");
+                    break;
+            }
+        }
+        while (true) {
+            System.out.print("Введите одну из команд - (list | save uuid | update uuid | delete uuid | get uuid | clear | exit): ");
+            params = reader.readLine().trim().toLowerCase().split(" ");
+            if (params.length < 1 || params.length > 2) {
+                System.out.println("Неверная команда.");
+                continue;
+            }
+            String uuid = null;
+            if (params.length == 2) {
+                uuid = params[1].intern();
+            }
+            switch (params[0]) {
+                case "list":
+                    printAll();
+                    break;
+                case "size":
+                    System.out.println(arrayStorage.size());
+                    break;
+                case "save":
+                    resume = new Resume(uuid);
+                    arrayStorage.save(resume);
+                    printAll();
+                    break;
+                case "update":
+                    resume = new Resume(uuid);
+                    arrayStorage.update(resume);
+                    printAll();
+                    break;
+                case "delete":
+                    arrayStorage.delete(uuid);
+                    printAll();
+                    break;
+                case "get":
+                    System.out.println(arrayStorage.get(uuid));
+                    break;
+                case "clear":
+                    arrayStorage.clear();
+                    printAll();
+                    break;
+                case "exit":
+                    return;
+                default:
+                    System.out.println("Неверная команда.");
+                    break;
+            }
+        }
+    }
+
+    static void printAll() {
+        Resume[] all = arrayStorage.getAll();
+        System.out.println("----------------------------");
+        if (all.length == 0) {
+            System.out.println("Empty");
+        } else {
+            for (Resume resume : all) {
+                System.out.println(resume);
+            }
+        }
+        System.out.println("----------------------------");
+    }
+}
\ No newline at end of file
diff --git a/src/ru/topjava/webapp/MainReflection.java b/src/ru/topjava/webapp/MainReflection.java
new file mode 100644
index 00000000..66613b5f
--- /dev/null
+++ b/src/ru/topjava/webapp/MainReflection.java
@@ -0,0 +1,14 @@
+package ru.topjava.webapp;
+
+import ru.topjava.webapp.model.Resume;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+public class MainReflection {
+    public static void main(String[] args) throws NoSuchMethodException, InvocationTargetException, IllegalAccessException {
+        Resume resume = new Resume("test_reflection");
+        Method toStringMethod = resume.getClass().getMethod("toString");
+        System.out.println(toStringMethod.invoke(resume));
+    }
+}
diff --git a/src/ru/topjava/webapp/MainTestArrayStorage.java b/src/ru/topjava/webapp/MainTestArrayStorage.java
new file mode 100644
index 00000000..2a01664b
--- /dev/null
+++ b/src/ru/topjava/webapp/MainTestArrayStorage.java
@@ -0,0 +1,54 @@
+package ru.topjava.webapp;
+
+import ru.topjava.webapp.model.Resume;
+import ru.topjava.webapp.storage.SortedArrayStorage;
+import ru.topjava.webapp.storage.Storage;
+
+import java.util.Arrays;
+
+/**
+ * Test for your ArrayStorage implementation
+ */
+public class MainTestArrayStorage {
+    static final Storage ARRAY_STORAGE = new SortedArrayStorage();
+
+    public static void main(String[] args) {
+        Resume resume1 = new Resume("uuid1");
+        Resume resume3 = new Resume("uuid3");
+        Resume resume2 = new Resume("uuid2");
+        Resume resume3Update = new Resume("uuid3");
+        Resume resume4 = new Resume("uuid4");
+
+        ARRAY_STORAGE.save(resume1);
+        ARRAY_STORAGE.save(resume2);
+        ARRAY_STORAGE.save(resume3);
+
+        System.out.println("Get resume1: " + ARRAY_STORAGE.get(resume1.getUuid()));
+        System.out.println("Size: " + ARRAY_STORAGE.size());
+
+        System.out.println("Get dummy: " + ARRAY_STORAGE.get("dummy"));
+
+        ARRAY_STORAGE.update(resume3Update);
+        System.out.println("Update resume3: " + (ARRAY_STORAGE.get("uuid3") == resume3Update));
+        System.out.println("Update non-existing resume4");
+        ARRAY_STORAGE.update(resume4);
+
+        System.out.println("resume2 index: " + Arrays.binarySearch(ARRAY_STORAGE.getAll(), resume2));
+        printAll();
+        ARRAY_STORAGE.delete(resume2.getUuid());
+        printAll();
+        System.out.println("resume2 index: " + Arrays.binarySearch(ARRAY_STORAGE.getAll(), resume2));
+        ARRAY_STORAGE.clear();
+        printAll();
+        System.out.println("resume2 index: " + Arrays.binarySearch(ARRAY_STORAGE.getAll(), resume2));
+
+        System.out.println("Size: " + ARRAY_STORAGE.size());
+    }
+
+    static void printAll() {
+        System.out.println("\nGet All");
+        for (Resume r : ARRAY_STORAGE.getAll()) {
+            System.out.println(r);
+        }
+    }
+}
diff --git a/src/ru/topjava/webapp/exception/ExistStorageException.java b/src/ru/topjava/webapp/exception/ExistStorageException.java
new file mode 100644
index 00000000..23abe86b
--- /dev/null
+++ b/src/ru/topjava/webapp/exception/ExistStorageException.java
@@ -0,0 +1,7 @@
+package ru.topjava.webapp.exception;
+
+public class ExistStorageException extends StorageException {
+    public ExistStorageException(String uuid) {
+        super(String.format("uuid '%1$s' is already exists", uuid), uuid);
+    }
+}
diff --git a/src/ru/topjava/webapp/exception/NotExistStorageException.java b/src/ru/topjava/webapp/exception/NotExistStorageException.java
new file mode 100644
index 00000000..9257fab3
--- /dev/null
+++ b/src/ru/topjava/webapp/exception/NotExistStorageException.java
@@ -0,0 +1,7 @@
+package ru.topjava.webapp.exception;
+
+public class NotExistStorageException extends StorageException {
+    public NotExistStorageException(String uuid) {
+        super(String.format("uuid '%1$s' is not exists", uuid), uuid);
+    }
+}
diff --git a/src/ru/topjava/webapp/exception/StorageException.java b/src/ru/topjava/webapp/exception/StorageException.java
new file mode 100644
index 00000000..864a4c54
--- /dev/null
+++ b/src/ru/topjava/webapp/exception/StorageException.java
@@ -0,0 +1,14 @@
+package ru.topjava.webapp.exception;
+
+public class StorageException extends RuntimeException{
+    private final String uuid;
+
+    public StorageException(String message, String uuid) {
+        super(message);
+        this.uuid = uuid;
+    }
+
+    public String getUuid() {
+        return uuid;
+    }
+}
diff --git a/src/ru/topjava/webapp/model/Resume.java b/src/ru/topjava/webapp/model/Resume.java
new file mode 100644
index 00000000..eea592b6
--- /dev/null
+++ b/src/ru/topjava/webapp/model/Resume.java
@@ -0,0 +1,49 @@
+package ru.topjava.webapp.model;
+
+import java.util.UUID;
+
+/**
+ * Initial resume class
+ */
+public class Resume implements Comparable<Resume> {
+
+    // Unique identifier
+    private final String uuid;
+
+    public Resume() {
+        this(UUID.randomUUID().toString());
+    }
+
+    public Resume(String uuid) {
+        this.uuid = uuid;
+    }
+
+    public String getUuid() {
+        return uuid;
+    }
+
+    @Override
+    public String toString() {
+        return uuid;
+    }
+
+    @Override
+    public boolean equals(Object object) {
+        if (this == object) return true;
+        if (object == null || getClass() != object.getClass()) return false;
+
+        Resume resume = (Resume) object;
+
+        return uuid.equals(resume.uuid);
+    }
+
+    @Override
+    public int hashCode() {
+        return uuid.hashCode();
+    }
+
+    @Override
+    public int compareTo(Resume resume) {
+        return uuid.compareTo(resume.uuid);
+    }
+}
diff --git a/src/ru/topjava/webapp/storage/AbstractArrayStorage.java b/src/ru/topjava/webapp/storage/AbstractArrayStorage.java
new file mode 100644
index 00000000..4a26b053
--- /dev/null
+++ b/src/ru/topjava/webapp/storage/AbstractArrayStorage.java
@@ -0,0 +1,66 @@
+package ru.topjava.webapp.storage;
+
+import ru.topjava.webapp.exception.StorageException;
+import ru.topjava.webapp.model.Resume;
+
+import java.util.Arrays;
+
+/**
+ * Array based storage for Resumes
+ */
+public abstract class AbstractArrayStorage extends AbstractStorage {
+    protected static final int STORAGE_LENGTH = 10000;
+    protected final Resume[] storage = new Resume[STORAGE_LENGTH];
+    protected int size = 0;
+
+    @Override
+    public void clear() {
+        Arrays.fill(storage, 0, size, null);
+        size = 0;
+    }
+
+    private void checkStorageIsNotFull(String uuid) {
+        if (size >= STORAGE_LENGTH) {
+            throw new StorageException("storage is full", uuid);
+        }
+    }
+
+    protected abstract void saveByIndexToArray(int resumeIndex, Resume resume);
+
+    @Override
+    protected void saveByKey(Object resumeKey, Resume resume) {
+        final String uuid = resume.getUuid();
+        checkStorageIsNotFull(uuid);
+        saveByIndexToArray((int) resumeKey, resume);
+        size++;
+    }
+
+    @Override
+    protected Resume getFromStorage(Object resumeKey) {
+        return storage[(int) resumeKey];
+    }
+
+    protected abstract void deleteByIndexFromArray(int resumeIndex);
+
+    @Override
+    protected void deleteByKey(Object resumeKey) {
+        deleteByIndexFromArray((int) resumeKey);
+        storage[size - 1] = null;
+        size--;
+    }
+
+    @Override
+    public Resume[] getAll() {
+        return Arrays.copyOf(storage, size);
+    }
+
+    @Override
+    public int size() {
+        return size;
+    }
+
+    @Override
+    protected void updateInStorage(Object resumeKey, Resume resume) {
+        storage[(int) resumeKey] = resume;
+    }
+}
diff --git a/src/ru/topjava/webapp/storage/AbstractStorage.java b/src/ru/topjava/webapp/storage/AbstractStorage.java
new file mode 100644
index 00000000..04ff56d7
--- /dev/null
+++ b/src/ru/topjava/webapp/storage/AbstractStorage.java
@@ -0,0 +1,56 @@
+package ru.topjava.webapp.storage;
+
+import ru.topjava.webapp.exception.ExistStorageException;
+import ru.topjava.webapp.exception.NotExistStorageException;
+import ru.topjava.webapp.model.Resume;
+
+public abstract class AbstractStorage implements Storage {
+
+    protected abstract Object getKey(String uuid);
+
+    protected abstract void saveByKey(Object resumeKey, Resume resume);
+
+    protected abstract void deleteByKey(Object resumeKey);
+
+    protected boolean isResumeExists(Object resumeKey) {
+        return ((int) resumeKey >= 0);
+    }
+
+    private Object findKeyIfResumeNotExist(String uuid) {
+        final Object resumeKey = getKey(uuid);
+        if (isResumeExists(resumeKey)) {
+            throw new ExistStorageException(uuid);
+        }
+        return resumeKey;
+    }
+
+    private Object findKeyIfResumeExist(String uuid) {
+        final Object resumeKey = getKey(uuid);
+        if (!isResumeExists(resumeKey)) {
+            throw new NotExistStorageException(uuid);
+        }
+        return resumeKey;
+    }
+
+    public final void save(Resume resume) {
+        final String uuid = resume.getUuid();
+        saveByKey(findKeyIfResumeNotExist(uuid), resume);
+    }
+
+    protected abstract Resume getFromStorage(Object resumeKey);
+
+    public final Resume get(String uuid) {
+        return getFromStorage(findKeyIfResumeExist(uuid));
+    }
+
+    public final void delete(String uuid) {
+        deleteByKey(findKeyIfResumeExist(uuid));
+    }
+
+    protected abstract void updateInStorage(Object resumeKey, Resume resume);
+
+    public final void update(Resume resume) {
+        final String uuid = resume.getUuid();
+        updateInStorage(findKeyIfResumeExist(uuid), resume);
+    }
+}
diff --git a/src/ru/topjava/webapp/storage/ArrayStorage.java b/src/ru/topjava/webapp/storage/ArrayStorage.java
new file mode 100644
index 00000000..9b5269de
--- /dev/null
+++ b/src/ru/topjava/webapp/storage/ArrayStorage.java
@@ -0,0 +1,28 @@
+package ru.topjava.webapp.storage;
+
+import ru.topjava.webapp.model.Resume;
+
+/**
+ * Unsorted array based storage for Resumes
+ */
+public class ArrayStorage extends AbstractArrayStorage {
+    @Override
+    protected Object getKey(String uuid) {
+        for (int i = 0; i < size; i++) {
+            if (storage[i].getUuid().equals(uuid)) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    @Override
+    protected void saveByIndexToArray(int resumeIndex, Resume resume) {
+        storage[size] = resume;
+    }
+
+    @Override
+    protected void deleteByIndexFromArray(int resumeIndex) {
+        storage[resumeIndex] = storage[size - 1];
+    }
+}
diff --git a/src/ru/topjava/webapp/storage/ListStorage.java b/src/ru/topjava/webapp/storage/ListStorage.java
new file mode 100644
index 00000000..9884b75c
--- /dev/null
+++ b/src/ru/topjava/webapp/storage/ListStorage.java
@@ -0,0 +1,56 @@
+package ru.topjava.webapp.storage;
+
+import ru.topjava.webapp.model.Resume;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ListStorage extends AbstractStorage {
+    private final List<Resume> storage = new ArrayList<>();
+
+    @Override
+    protected Object getKey(String uuid) {
+        for (int i = 0; i < storage.size(); i++) {
+            if (storage.get(i).getUuid().equals(uuid)) {
+                return i;
+            }
+        }
+        return -1;
+    }
+
+    @Override
+    protected void saveByKey(Object resumeKey, Resume resume) {
+        storage.add(resume);
+    }
+
+    @Override
+    protected void deleteByKey(Object resumeKey) {
+        storage.remove((int) resumeKey);
+    }
+
+    @Override
+    public void clear() {
+        storage.clear();
+    }
+
+    @Override
+    protected Resume getFromStorage(Object resumeKey) {
+        return storage.get((int) resumeKey);
+    }
+
+    @Override
+    public Resume[] getAll() {
+        final Resume[] tempArray = new Resume[this.size()];
+        return storage.toArray(tempArray);
+    }
+
+    @Override
+    public int size() {
+        return storage.size();
+    }
+
+    @Override
+    protected void updateInStorage(Object resumeKey, Resume resume) {
+        storage.set((int) resumeKey, resume);
+    }
+}
diff --git a/src/ru/topjava/webapp/storage/MapStorage.java b/src/ru/topjava/webapp/storage/MapStorage.java
new file mode 100644
index 00000000..86319a3b
--- /dev/null
+++ b/src/ru/topjava/webapp/storage/MapStorage.java
@@ -0,0 +1,56 @@
+package ru.topjava.webapp.storage;
+
+import ru.topjava.webapp.model.Resume;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class MapStorage extends AbstractStorage {
+    private final Map<String, Resume> storage = new HashMap<>();
+
+    @Override
+    protected Object getKey(String uuid) {
+        return uuid;
+    }
+
+    @Override
+    protected void saveByKey(Object uuid, Resume resume) {
+        storage.put((String) uuid, resume);
+    }
+
+    @Override
+    protected void deleteByKey(Object uuid) {
+        storage.remove((String) uuid);
+    }
+
+    @Override
+    protected boolean isResumeExists(Object uuid) {
+        return storage.containsKey((String) uuid);
+    }
+
+    @Override
+    public void clear() {
+        storage.clear();
+    }
+
+    @Override
+    protected Resume getFromStorage(Object uuid) {
+        return storage.get((String) uuid);
+    }
+
+    @Override
+    public Resume[] getAll() {
+        final Resume[] tempArray = new Resume[this.size()];
+        return storage.values().toArray(tempArray);
+    }
+
+    @Override
+    public int size() {
+        return storage.size();
+    }
+
+    @Override
+    protected void updateInStorage(Object uuid, Resume resume) {
+        storage.replace((String) uuid, resume);
+    }
+}
diff --git a/src/ru/topjava/webapp/storage/SortedArrayStorage.java b/src/ru/topjava/webapp/storage/SortedArrayStorage.java
new file mode 100644
index 00000000..4b23a22a
--- /dev/null
+++ b/src/ru/topjava/webapp/storage/SortedArrayStorage.java
@@ -0,0 +1,28 @@
+package ru.topjava.webapp.storage;
+
+import ru.topjava.webapp.model.Resume;
+
+import java.util.Arrays;
+
+/**
+ * Sorted array based storage for Resumes
+ */
+public class SortedArrayStorage extends AbstractArrayStorage {
+    @Override
+    protected Object getKey(String uuid) {
+        final Resume resumeToSearch = new Resume(uuid);
+        return Arrays.binarySearch(storage, 0, size, resumeToSearch);
+    }
+
+    @Override
+    protected void saveByIndexToArray(int resumeIndex, Resume resume) {
+        final int resumeIndexToSave = -resumeIndex - 1;
+        System.arraycopy(storage, resumeIndexToSave, storage, resumeIndexToSave + 1, size - resumeIndexToSave);
+        storage[resumeIndexToSave] = resume;
+    }
+
+    @Override
+    protected void deleteByIndexFromArray(int resumeIndex) {
+        System.arraycopy(storage, resumeIndex + 1, storage, resumeIndex, size - resumeIndex - 1);
+    }
+}
diff --git a/src/ru/topjava/webapp/storage/Storage.java b/src/ru/topjava/webapp/storage/Storage.java
new file mode 100644
index 00000000..749438a3
--- /dev/null
+++ b/src/ru/topjava/webapp/storage/Storage.java
@@ -0,0 +1,26 @@
+package ru.topjava.webapp.storage;
+
+import ru.topjava.webapp.model.Resume;
+
+/**
+ * Array based storage for Resumes
+ */
+public interface Storage {
+
+    void clear();
+
+    void save(Resume resume);
+
+    Resume get(String uuid);
+
+    void delete(String uuid);
+
+    /**
+     * @return array, contains only Resumes in storage (without null)
+     */
+    Resume[] getAll();
+
+    int size();
+
+    void update(Resume resume);
+}
diff --git a/test/ru/topjava/webapp/storage/AbstractArrayStorageTest.java b/test/ru/topjava/webapp/storage/AbstractArrayStorageTest.java
new file mode 100644
index 00000000..224ee3ee
--- /dev/null
+++ b/test/ru/topjava/webapp/storage/AbstractArrayStorageTest.java
@@ -0,0 +1,28 @@
+package ru.topjava.webapp.storage;
+
+import org.junit.Assert;
+import org.junit.Test;
+import ru.topjava.webapp.exception.StorageException;
+import ru.topjava.webapp.model.Resume;
+
+import static ru.topjava.webapp.storage.AbstractArrayStorage.STORAGE_LENGTH;
+
+public abstract class AbstractArrayStorageTest extends AbstractStorageTest {
+
+    public AbstractArrayStorageTest(Storage storage) {
+        super(storage);
+    }
+
+    @Test(expected = StorageException.class)
+    public void saveStorageFull() {
+        int initialSize = storage.size();
+        try {
+            for (int i = 0; i < STORAGE_LENGTH - initialSize; i++) {
+                storage.save(new Resume());
+            }
+        } catch (StorageException e) {
+            Assert.fail("StorageException thrown earlier, than expected");
+        }
+        storage.save(new Resume());
+    }
+}
\ No newline at end of file
diff --git a/test/ru/topjava/webapp/storage/AbstractStorageTest.java b/test/ru/topjava/webapp/storage/AbstractStorageTest.java
new file mode 100644
index 00000000..7e4c6c9d
--- /dev/null
+++ b/test/ru/topjava/webapp/storage/AbstractStorageTest.java
@@ -0,0 +1,102 @@
+package ru.topjava.webapp.storage;
+
+import org.junit.Assert;
+import org.junit.Before;
+import org.junit.Test;
+import ru.topjava.webapp.exception.ExistStorageException;
+import ru.topjava.webapp.exception.NotExistStorageException;
+import ru.topjava.webapp.model.Resume;
+
+import java.util.Arrays;
+
+public abstract class AbstractStorageTest {
+    protected final Storage storage;
+    protected final Resume resume1;
+    protected final Resume resume2;
+    protected final Resume resume3;
+    protected final Resume resume4;
+
+    public AbstractStorageTest(Storage storage) {
+        this.storage = storage;
+        resume1 = new Resume("uuid1");
+        resume2 = new Resume("uuid2");
+        resume3 = new Resume("uuid3");
+        resume4 = new Resume("uuid4");
+    }
+
+    @Before
+    public void setUp() {
+        storage.clear();
+        storage.save(resume1);
+        storage.save(resume2);
+        storage.save(resume3);
+    }
+
+    @Test
+    public void save() {
+        storage.save(resume4);
+        Assert.assertEquals(resume4, storage.get("uuid4"));
+        Assert.assertEquals(4, storage.size());
+    }
+
+    @Test(expected = ExistStorageException.class)
+    public void saveExist() {
+        storage.save(resume2);
+    }
+
+    @Test(expected = NotExistStorageException.class)
+    public void delete() {
+        try {
+            storage.delete(resume2.getUuid());
+            Assert.assertEquals(2, storage.size());
+        } catch (NotExistStorageException e) {
+            Assert.fail("NotExistStorageException thrown earlier, than expected");
+        }
+        storage.get("uuid2");
+    }
+
+    @Test(expected = NotExistStorageException.class)
+    public void deleteNotExist() {
+        storage.delete(resume4.getUuid());
+    }
+
+    @Test
+    public void update() {
+        final Resume resume3Update = new Resume("uuid3");
+        storage.update(resume3Update);
+        Assert.assertEquals(resume3Update, storage.get("uuid3"));
+    }
+
+    @Test(expected = NotExistStorageException.class)
+    public void updateNotExist() {
+        storage.update(resume4);
+    }
+
+    @Test
+    public void get() {
+        Assert.assertEquals(resume1, storage.get("uuid1"));
+    }
+
+    @Test(expected = NotExistStorageException.class)
+    public void getNotExist() {
+        storage.get(resume4.getUuid());
+    }
+
+    @Test
+    public void getAll() {
+        final Resume[] expected = new Resume[]{resume1, resume2, resume3};
+        final Resume[] actual = storage.getAll();
+        Arrays.sort(actual);
+        Assert.assertArrayEquals(expected, actual);
+    }
+
+    @Test
+    public void size() {
+        Assert.assertEquals(3, storage.size());
+    }
+
+    @Test
+    public void clear() {
+        storage.clear();
+    }
+}
\ No newline at end of file
diff --git a/test/ru/topjava/webapp/storage/ArrayStorageTest.java b/test/ru/topjava/webapp/storage/ArrayStorageTest.java
new file mode 100644
index 00000000..8d56dc60
--- /dev/null
+++ b/test/ru/topjava/webapp/storage/ArrayStorageTest.java
@@ -0,0 +1,8 @@
+package ru.topjava.webapp.storage;
+
+public class ArrayStorageTest extends AbstractArrayStorageTest {
+
+    public ArrayStorageTest() {
+        super(new ArrayStorage());
+    }
+}
\ No newline at end of file
diff --git a/test/ru/topjava/webapp/storage/ListStorageTest.java b/test/ru/topjava/webapp/storage/ListStorageTest.java
new file mode 100644
index 00000000..3db08fb5
--- /dev/null
+++ b/test/ru/topjava/webapp/storage/ListStorageTest.java
@@ -0,0 +1,8 @@
+package ru.topjava.webapp.storage;
+
+public class ListStorageTest extends AbstractStorageTest {
+
+    public ListStorageTest() {
+        super(new ListStorage());
+    }
+}
\ No newline at end of file
diff --git a/test/ru/topjava/webapp/storage/MapStorageTest.java b/test/ru/topjava/webapp/storage/MapStorageTest.java
new file mode 100644
index 00000000..5b797ba3
--- /dev/null
+++ b/test/ru/topjava/webapp/storage/MapStorageTest.java
@@ -0,0 +1,8 @@
+package ru.topjava.webapp.storage;
+
+public class MapStorageTest extends AbstractStorageTest {
+
+    public MapStorageTest() {
+        super(new MapStorage());
+    }
+}
\ No newline at end of file
diff --git a/test/ru/topjava/webapp/storage/SortedArrayStorageTest.java b/test/ru/topjava/webapp/storage/SortedArrayStorageTest.java
new file mode 100644
index 00000000..3812fe52
--- /dev/null
+++ b/test/ru/topjava/webapp/storage/SortedArrayStorageTest.java
@@ -0,0 +1,8 @@
+package ru.topjava.webapp.storage;
+
+public class SortedArrayStorageTest extends AbstractArrayStorageTest {
+
+    public SortedArrayStorageTest() {
+        super(new SortedArrayStorage());
+    }
+}
\ No newline at end of file