Upgrade to Java 25 and Spring Boot 4

README.md

@@ -1,10 +1,10 @@
 # ![RealWorld Example App](logo.png)
 
-> ### **Java 21 + Spring Boot 3** codebase containing real-world examples (CRUD, authentication, advanced patterns, etc.) that adheres to the [RealWorld](https://github.com/gothinkster/realworld) specification and API.
+> ### **Java 25 + Spring Boot 4** codebase containing real-world examples (CRUD, authentication, advanced patterns, etc.) that adheres to the [RealWorld](https://github.com/gothinkster/realworld) specification and API.
 
 ### [Demo](https://demo.realworld.io/)      [RealWorld](https://github.com/gothinkster/realworld)
 
-This codebase demonstrates a fully-fledged fullstack application built with **Java 21 + Spring Boot 3**, including CRUD operations, authentication, routing, pagination, and more.
+This codebase demonstrates a fully-fledged fullstack application built with **Java 25 + Spring Boot 4**, including CRUD operations, authentication, routing, pagination, and more.
 
 If you want to see the API documentation related to this, please refer to https://1chz.github.io/realworld-java21-springboot3
 
@@ -65,9 +65,9 @@ This application provides the following key features:
 
 ### Project Structure
 
-The project is implemented using Java 21 and Spring Boot 3, leveraging technologies such as Spring MVC, Spring Data JPA, and Spring Security. It uses H2 DB (in-memory, MySQL mode) as the database and JUnit 5 for testing.
+The project is implemented using Java 25 and Spring Boot 4, leveraging technologies such as Spring MVC, Spring Data JPA, and Spring Security. It uses H2 DB (in-memory, MySQL mode) as the database and JUnit 5 for testing.
 
-To run the project, ensure that JDK (or JRE) 21 is installed. Then, execute the following command in the project root directory:
+To run the project, ensure that JDK (or JRE) 25 is installed. Then, execute the following command in the project root directory:
 
 ```shell
 ./gradlew realworld:bootRun
@@ -110,7 +110,7 @@ Many developers using JPA tend to use `Long` as the ID type. However, consider w
 
 ## Getting Started
 
-> **Note:** Ensure JDK 21 is installed.
+> **Note:** Ensure JDK 25 is installed.
 >
 > **Note:** If you encounter a permission denied error when running Gradle tasks, run `chmod +x gradlew` to grant execution permission.
 

build.gradle.kts

@@ -36,7 +36,8 @@ allprojects {
 
     spotless {
         java {
-            palantirJavaFormat().formatJavadoc(true)
+            // https://github.com/palantir/palantir-java-format/releases/tag/2.71.0
+            palantirJavaFormat("2.71.0").formatJavadoc(true)
 
             formatAnnotations()
             removeUnusedImports()

gradle/libs.versions.toml

@@ -1,10 +1,9 @@
 [versions]
-java = "21"
-spotless = "7.0.3"
+java = "25"
+spotless = "7.2.1"
 
-spring-boot = "3.3.0"
-spring-dependency-management = "1.1.5"
-spring-boot-p6spy = "1.9.0"
+spring-boot = "4.0.0-M2"
+spring-dependency-management = "1.1.7"
 
 [libraries]
 lombok = { group = "org.projectlombok", name = "lombok" }
@@ -19,7 +18,6 @@ spring-boot-starter-web = { group = "org.springframework.boot", name = "spring-b
 spring-boot-starter-cache = { group = "org.springframework.boot", name = "spring-boot-starter-cache" }
 spring-boot-starter-data-jpa = { group = "org.springframework.boot", name = "spring-boot-starter-data-jpa" }
 spring-boot-starter-oauth2-resource-server = { group = "org.springframework.boot", name = "spring-boot-starter-oauth2-resource-server" }
-spring-boot-starter-p6spy = { group = "com.github.gavlyukovskiy", name = "p6spy-spring-boot-starter", version.ref = "spring-boot-p6spy" }
 
 cache-caffeine = { group = "com.github.ben-manes.caffeine", name = "caffeine" }
 

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-8.5-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.1.0-bin.zip
 networkTimeout=10000
 validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME

gradlew

@@ -1,7 +1,7 @@
 #!/bin/sh
 
 #
-# Copyright © 2015-2021 the original authors.
+# Copyright © 2015 the original authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -15,6 +15,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 
 ##############################################################################
 #
@@ -55,7 +57,7 @@
 #       Darwin, MinGW, and NonStop.
 #
 #   (3) This script is generated from the Groovy template
-#       https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
 #       within the Gradle project.
 #
 #       You can find Gradle at https://github.com/gradle/gradle/.
@@ -80,13 +82,11 @@ do
     esac
 done
 
-APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit
-
-APP_NAME="Gradle"
+# This is normally unused
+# shellcheck disable=SC2034
 APP_BASE_NAME=${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"'
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
 MAX_FD=maximum
@@ -114,7 +114,6 @@ case "$( uname )" in                #(
   NONSTOP* )        nonstop=true ;;
 esac
 
-CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
 
 # Determine the Java command to use to start the JVM.
@@ -133,22 +132,29 @@ 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.
+    if ! command -v java >/dev/null 2>&1
+    then
+        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
 fi
 
 # Increase the maximum file descriptors if we can.
 if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
     case $MAX_FD in #(
       max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
         MAX_FD=$( ulimit -H -n ) ||
             warn "Could not query maximum file descriptor limit"
     esac
     case $MAX_FD in  #(
       '' | soft) :;; #(
       *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
         ulimit -n "$MAX_FD" ||
             warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
@@ -165,7 +171,6 @@ fi
 # For Cygwin or MSYS, switch paths to Windows format before running java
 if "$cygwin" || "$msys" ; then
     APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
-    CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" )
 
     JAVACMD=$( cygpath --unix "$JAVACMD" )
 
@@ -193,16 +198,19 @@ if "$cygwin" || "$msys" ; then
     done
 fi
 
-# Collect all arguments for the java command;
-#   * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of
-#     shell script including quotes and variable substitutions, so put them in
-#     double quotes to make sure that they get re-expanded; and
-#   * put everything else in single quotes, so that it's not re-expanded.
+
+# 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"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
 
 set -- \
         "-Dorg.gradle.appname=$APP_BASE_NAME" \
-        -classpath "$CLASSPATH" \
-        org.gradle.wrapper.GradleWrapperMain \
+        -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
         "$@"
 
 # Stop when "xargs" is not available.

gradlew.bat

@@ -13,6 +13,8 @@
 @rem See the License for the specific language governing permissions and
 @rem limitations under the License.
 @rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
 
 @if "%DEBUG%"=="" @echo off
 @rem ##########################################################################
@@ -26,6 +28,7 @@ if "%OS%"=="Windows_NT" setlocal
 
 set DIRNAME=%~dp0
 if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
@@ -42,11 +45,11 @@ set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
 if %ERRORLEVEL% equ 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.
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail
 
@@ -56,22 +59,21 @@ 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.
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 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 %*
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
 
 :end
 @rem End local scope for the variables with windows NT shell

module/core/src/main/java/io/zhc1/realworld/model/Tag.java

@@ -1,6 +1,7 @@
 package io.zhc1.realworld.model;
 
 import java.time.LocalDateTime;
+import java.util.Comparator;
 import java.util.Objects;
 
 import jakarta.persistence.Column;
@@ -17,7 +18,7 @@
 @Table(name = "tag")
 @SuppressWarnings("JpaDataSourceORMInspection")
 @NoArgsConstructor(access = AccessLevel.PROTECTED)
-public class Tag {
+public class Tag implements Comparable<Tag> {
     @Id
     @Column(length = 20)
     private String name;
@@ -42,4 +43,9 @@ public boolean equals(Object o) {
     public int hashCode() {
         return Objects.hash(this.getName());
     }
+
+    @Override
+    public int compareTo(Tag other) {
+        return Comparator.comparing(Tag::getName).compare(this, other);
+    }
 }

module/core/src/main/java/io/zhc1/realworld/service/ArticleService.java

@@ -75,6 +75,10 @@ public List<ArticleDetails> getFeeds(User user, ArticleFacets facets) {
                 .map(UserFollow::getFollowing)
                 .toList();
 
+        if (following.isEmpty()) {
+            return List.of();
+        }
+
         return articleRepository.findByAuthors(following, facets).stream()
                 .map(article -> articleRepository.findArticleDetails(user, article))
                 .toList();

module/core/src/test/java/io/zhc1/realworld/service/ArticleServiceTest.java

@@ -194,7 +194,6 @@ void whenGetFeedsWithEmptyFollowings_thenShouldReturnEmptyList() {
         User user = new User("email", "username", "password");
         ArticleFacets facets = new ArticleFacets(1, 10);
         when(userRelationshipRepository.findByFollower(user)).thenReturn(List.of());
-        when(articleRepository.findByAuthors(List.of(), facets)).thenReturn(List.of());
 
         // when
         List<ArticleDetails> actualArticleDetailsList = sut.getFeeds(user, facets);

module/persistence/build.gradle.kts

@@ -5,7 +5,6 @@ dependencies {
 
     implementation(libs.spring.boot.starter.data.jpa)
     implementation(libs.spring.boot.starter.cache)
-    implementation(libs.spring.boot.starter.p6spy)
 
     implementation(libs.cache.caffeine)
 }