This is the first checkin of the working code

.gitignore

+# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio and WebStorm
+# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
+
+# User-specific stuff
+.idea/**/workspace.xml
+.idea/**/tasks.xml
+.idea/**/usage.statistics.xml
+.idea/**/dictionaries
+.idea/**/shelf
+
+# Generated files
+.idea/**/contentModel.xml
+
+# Sensitive or high-churn files
+.idea/**/dataSources/
+.idea/**/dataSources.ids
+.idea/**/dataSources.local.xml
+.idea/**/sqlDataSources.xml
+.idea/**/dynamic.xml
+.idea/**/uiDesigner.xml
+.idea/**/dbnavigator.xml
+
+# Gradle
+.idea/**/gradle.xml
+.idea/**/libraries
+.gradle/
+
+# Gradle and Maven with auto-import
+# When using Gradle or Maven with auto-import, you should exclude module files,
+# since they will be recreated, and may cause churn.  Uncomment if using
+# auto-import.
+# .idea/modules.xml
+# .idea/*.iml
+# .idea/modules
+
+# CMake
+cmake-build-*/
+
+# Mongo Explorer plugin
+.idea/**/mongoSettings.xml
+
+# File-based project format
+*.iws
+
+# IntelliJ
+out/
+build/
+
+# mpeltonen/sbt-idea plugin
+.idea_modules/
+
+# JIRA plugin
+atlassian-ide-plugin.xml
+
+# Cursive Clojure plugin
+.idea/replstate.xml
+
+# Crashlytics plugin (for Android Studio and IntelliJ)
+com_crashlytics_export_strings.xml
+crashlytics.properties
+crashlytics-build.properties
+fabric.properties
+
+# Editor-based Rest Client
+.idea/httpRequests
+
+# Android studio 3.1+ serialized cache file
+.idea/caches/build_file_checksums.ser

build.gradle

+buildscript {
+	ext {
+		springBootVersion = '2.1.1.RELEASE'
+	}
+	repositories {
+		mavenCentral()
+	}
+	dependencies {
+		classpath("org.springframework.boot:spring-boot-gradle-plugin:${springBootVersion}")
+	}
+}
+
+plugins {
+    id "org.flywaydb.flyway" version "5.2.4"
+}
+
+flyway {
+    url= "jdbc:postgresql://localhost:26257/testdb"
+    user= "user17"
+}
+
+apply plugin: 'java'
+apply plugin: 'eclipse'
+apply plugin: 'org.springframework.boot'
+apply plugin: 'io.spring.dependency-management'
+
+group = 'com.gmu.bookshare'
+version = '0.0.1-SNAPSHOT'
+sourceCompatibility = 1.8
+
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	implementation('org.springframework.boot:spring-boot-starter-data-jpa')
+	implementation('org.springframework.boot:spring-boot-starter-data-rest')
+	implementation('org.springframework.boot:spring-boot-starter-web')
+	implementation('org.modelmapper:modelmapper:2.3.1')
+    compile group: 'org.postgresql', name: 'postgresql', version: '42.2.5'
+	compileOnly('org.projectlombok:lombok')
+	testImplementation('org.springframework.boot:spring-boot-starter-test')
+	testImplementation('org.assertj:assertj-core')
+	testImplementation('com.h2database:h2')
+}

gradle/wrapper/gradle-wrapper.properties

+#Sun Dec 09 21:00:01 EST 2018
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-4.10.2-all.zip

gradlew

+#!/usr/bin/env sh
+
+##############################################################################
+##
+##  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 "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS=""
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+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, switch paths to Windows format before running java
+if $cygwin ; then
+    APP_HOME=`cygpath --path --mixed "$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" "$@"

gradlew.bat

+@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=
+
+@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

settings.gradle

+rootProject.name = 'demo'

src/main/java/com/gmu/bookshare/BookshareApplication.java

+package com.gmu.bookshare;
+
+import org.modelmapper.ModelMapper;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+@SpringBootApplication
+public class BookshareApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(BookshareApplication.class, args);
+    }
+
+    @Bean
+    public ModelMapper modelMapper() {
+        return new ModelMapper();
+    }
+}

src/main/java/com/gmu/bookshare/beer/Beer.java

+package com.gmu.bookshare.beer;
+
+import lombok.Data;
+import lombok.NoArgsConstructor;
+import lombok.NonNull;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Id;
+
+@Data
+@NoArgsConstructor
+@Entity
+class Beer {
+
+    public Beer(String name) {
+        this.name = name;
+    }
+
+    @Id
+    @GeneratedValue
+    private Long id;
+
+    @NonNull
+    private String name;
+}
\ No newline at end of file

src/main/java/com/gmu/bookshare/beer/BeerCommandLineRunner.java

+package com.gmu.bookshare.beer;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class BeerCommandLineRunner {//implements CommandLineRunner {
+
+//    private final BeerRepository repository;
+//
+//    public BeerCommandLineRunner(BeerRepository repository) {
+//        this.repository = repository;
+//    }
+//
+//    @Override
+//    public void run(String... strings) throws Exception {
+//        // Top beers from https://www.beeradvocate.com/lists/us, November 2018
+//        Stream.of("Kentucky Brunch Brand Stout", "Marshmallow Handjee", "Barrel-Aged Abraxas",
+//                "Hunahpu's Imperial Stout", "King Julius", "Heady Topper",
+//                "Budweiser", "Coors Light", "PBR").forEach(name ->
+//                repository.save(new Beer(name))
+//        );
+//        repository.findAll().forEach(System.out::println);
+//    }
+}
\ No newline at end of file

src/main/java/com/gmu/bookshare/beer/BeerController.java

+package com.gmu.bookshare.beer;
+
+import org.springframework.web.bind.annotation.CrossOrigin;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Collection;
+import java.util.stream.Collectors;
+
+@RestController
+public class BeerController {
+    private BeerRepository repository;
+
+    public BeerController(BeerRepository repository) {
+        this.repository = repository;
+    }
+
+    @GetMapping("/good-beers")
+    @CrossOrigin(origins = "http://localhost:8081")
+    public Collection<Beer> goodBeers() {
+        return repository.findAll().stream()
+                .filter(this::isGreat)
+                .collect(Collectors.toList());
+    }
+
+    private boolean isGreat(Beer beer) {
+        return !beer.getName().equals("Budweiser") &&
+                !beer.getName().equals("Coors Light") &&
+                !beer.getName().equals("PBR");
+    }
+}
\ No newline at end of file

src/main/java/com/gmu/bookshare/beer/BeerRepository.java

+package com.gmu.bookshare.beer;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.rest.core.annotation.RepositoryRestResource;
+
+@RepositoryRestResource
+interface BeerRepository extends JpaRepository<Beer, Long> {
+}
\ No newline at end of file

src/main/java/com/gmu/bookshare/entity/Bid.java

+package com.gmu.bookshare.entity;
+
+import lombok.*;
+
+import javax.persistence.*;
+import java.util.Date;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@Entity
+@Table(name = "bid")
+@Getter
+@Setter
+public class Bid {
+
+    @Id
+    @GeneratedValue
+    @Column(name = "id", updatable = false)
+    private Long id;
+
+    @Column(name = "createDate")
+    private Date createDate;
+
+    @Column(name = "price")
+    private double price;
+
+    @Column(name = "flag")
+    private int flagged;
+
+    @Column(name = "userId")
+    private Long userId;
+
+    @Column(name = "listingId")
+    private Long listingId;
+}

src/main/java/com/gmu/bookshare/entity/ListingEntity.java

+package com.gmu.bookshare.entity;
+
+import lombok.*;
+
+import javax.persistence.*;
+import java.util.Date;
+
+@Data
+@NoArgsConstructor
+@RequiredArgsConstructor
+@AllArgsConstructor
+@Entity
+@Getter
+@Setter
+@Table(name = "listing")
+public class ListingEntity {
+
+    @Id
+    @GeneratedValue
+    @Column(name = "id", updatable = false)
+    private Long id;
+
+    @Column(name = "course")
+    private String course;
+
+    @NonNull
+    @Column(name = "isbn")
+    private int isbn;
+
+    @NonNull
+    @Column(name = "condition")
+    private int condition;
+
+    @Column(name = "accessCode")
+    private boolean accessCode;
+
+    @NonNull
+    @Column(name = "price")
+    private double price;
+
+    @Column(name = "image")
+    private byte[] image;
+
+    @Column(name = "description")
+    private String description;
+
+    @NonNull
+    @Column(name = "createDate")
+    private Date createDate;
+
+    @NonNull
+    @Column(name = "bid_id")
+    private Long bid_id;
+
+    @NonNull
+    @Column(name = "owner")
+    private Long owner;
+
+    @NonNull
+    @Column(name = "title")
+    private String title;
+}

src/main/java/com/gmu/bookshare/entity/ShareUser.java

+package com.gmu.bookshare.entity;
+
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+
+import javax.persistence.*;
+
+@Data
+@NoArgsConstructor
+@AllArgsConstructor
+@Entity
+@Table(name = "user")
+@Getter
+public class ShareUser {
+
+    @Id
+    @GeneratedValue
+    @Column(name = "id", updatable = false)