Upgrade to Spring Boot 3.2.5 and Java 17

[devin-ai-integration]

Summary

Upgrades the project from Spring Boot 2.0.2.RELEASE / Java 8 to Spring Boot 3.2.5 / Java 17, plus the related code fixes that the upgrade requires.

Build configuration

• pom.xml: bump spring-boot-starter-parent to 3.2.5, set <java.version>17</java.version>, drop the obsolete spring-boot-properties-migrator (was only needed for the 1.x → 2.x migration)
• build.gradle: bump spring-boot-gradle-plugin to 3.2.5, set sourceCompatibility / targetCompatibility to 17, replace deprecated compile / testCompile with implementation / testImplementation, add spring-boot-starter-jdbc + h2 so it matches pom.xml, and replace the removed bootJar { baseName / version } properties with archiveBaseName / archiveVersion
• gradle/wrapper/gradle-wrapper.properties: bump the wrapper from Gradle 4.6 to 8.5 (required for Spring Boot 3.x); gradlew is now executable

Code fixes in src/main/java/hello/Application.java

• DROP TABLE customers IF EXISTS → DROP TABLE IF EXISTS customers (H2 2.x dropped the legacy syntax)
• Switched JdbcTemplate.query(...) to the RowMapper-before-varargs overload, replacing the deprecated Object[]-args form
• Removed the dead http://gturnquist-quoters.cfapps.io/api/random calls (both the one in main and the CommandLineRunner run bean), the RestTemplate bean, and the unused RestTemplateBuilder import
• Removed the now-unused hello.model.Quote and hello.model.Value classes

Docs / hygiene

• README.md: prerequisites updated to Java 17 SDK and a note that the project now targets Spring Boot 3.x
• .gitignore: ignore target/, build/, .gradle/; the previously-committed stale target/classes/*.class artifacts (which were compiled against Java 8 / Spring Boot 2 and no longer match the source) are removed. src/main/resources/public/index.html is the real welcome-page source and is unaffected

Verification

Both build systems succeed locally on Java 17:

• JAVA_HOME=java-17 mvn -B clean package → BUILD SUCCESS (Maven 3.6.3)
• JAVA_HOME=java-17 ./gradlew --no-daemon build → BUILD SUCCESSFUL (Gradle 8.5)

The packaged Gradle jar (build/libs/gs-spring-boot-0.1.0.jar) was started with Java 17 and:

• Reported Spring Boot :: (v3.2.5) in the banner
• Booted Tomcat 10.1.20 on port 8080
• Created the customers H2 table, batch-inserted the four rows, and queried the two Josh* rows back through the new JdbcTemplate.query(..., rowMapper, args...) signature — Customer{id=3, firstName='Josh', lastName='Bloch'} and Customer{id=4, firstName='Josh', lastName='Long'}

Review & Testing Checklist for Human

• Confirm CI passes on Java 17 for both Maven and Gradle paths (the repo had no .github/workflows, so CI may be a separate concern)
• mvn clean package and ./gradlew build on a clean checkout with JDK 17 set as JAVA_HOME
• Smoke test the running app: java -jar build/libs/gs-spring-boot-0.1.0.jar, then exercise GET /, GET /topic, GET /datetime, GET /topic/string/operation, GET /topic/file/operation — these existing endpoints were not touched but should be confirmed still work end-to-end on Spring Boot 3
• Confirm you're OK with deleting the previously-committed target/classes/*.class build artifacts; if you want them kept, I can revert that piece

Notes

• pom.xml packaging is pom, which means mvn package does not produce a runnable jar. I left the packaging as-is because changing it is outside the scope of this upgrade. The Gradle build does produce a runnable jar in build/libs/, which is what I used to verify the app actually starts.
• No javax.* imports exist in src/, so no javax → jakarta changes were required.
• No .pre-commit-config.yaml or .husky/ is present in the repo, so no hook setup was needed.

Link to Devin session: https://app.devin.ai/sessions/9025b18a88794071956d8a9761324e2b
Requested by: @bcmake

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[devin-ai-integration]

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[devin-ai-integration]

Runtime test results — all 11 tests passed

I booted build/libs/gs-spring-boot-0.1.0.jar on Java 17 from the repo root and exercised every existing REST endpoint plus the H2 startup demo. Shell-only testing (no GUI to record).

#	Test	Result
T1	Banner shows (v3.2.5), log shows Java 17, Tomcat/10.1.20, port 8080	✅ passed
T2	H2 DDL: Creating tables + 4 customer inserts, no JdbcSQLSyntaxErrorException	✅ passed
T3	New JdbcTemplate.query(sql, RowMapper, args) overload returns Josh Bloch (id=3) and Josh Long (id=4)	✅ passed
T4	GET / → 200, JSON greeting, counter increments across calls	✅ passed
T5	GET /topic → 200, 3 seeded items, ids [spring, java, javascript]	✅ passed
T6	Topic CRUD round-trip: POST→GET→PUT→GET→DELETE→GET	✅ passed
T7	GET /topic/sort → ids ordered [java, javascript, spring]	✅ passed
T8	GET /topic/minimum/length/{4,9} → [javascript, spring] and [javascript]	✅ passed
T9	GET /datetime → 200, all expected substrings, "tomorrow" = "now" + 1 day	✅ passed
T10	GET /topic/string/operation → 200, returns [spring] for "id has 'g'" filter	✅ passed
T11	GET /topic/file/operation → 200, Hello, this, is, Rehman (NOT IO exception)	✅ passed

Key evidence — startup log proves the H2 + JdbcTemplate fixes (click to expand)

 :: Spring Boot ::                (v3.2.5)
... Starting Application using Java 17.0.18 ...
... Starting Servlet engine: [Apache Tomcat/10.1.20]
... Tomcat started on port 8080 (http) with context path ''
... Started Application in 2.37 seconds ...
... hello.Application : Creating tables
... hello.Application : Inserting customer record for John Woo
... hello.Application : Inserting customer record for Jeff Dean
... hello.Application : Inserting customer record for Josh Bloch
... hello.Application : Inserting customer record for Josh Long
... hello.Application : Querying for customer records where first_name = 'Josh':
... hello.Application : Customer{id=3, firstName='Josh', lastName='Bloch'}
... hello.Application : Customer{id=4, firstName='Josh', lastName='Long'}

These two Customer{...} lines are the exact assertion the plan demanded — they prove BOTH the H2 2.x DDL fix (no syntax error blocking startup) AND the new JdbcTemplate.query(sql, RowMapper, args...) overload binding the ? placeholder correctly to "Josh".

Topic CRUD round-trip evidence

POST   /topic     → HTTP 200
GET    /topic/py  → 200 {"id":"py","subjectName":"Python","subjectDescription":"Python Description"}
PUT    /topic/py  → HTTP 200
GET    /topic/py  → 200 {"id":"py","subjectName":"Python 3","subjectDescription":"Updated"}
DELETE /topic/py  → HTTP 200
GET    /topic     → 200 (back to original 3 items: spring, java, javascript)

Notes / things I did NOT test

• No unit tests exist in src/test/.
• mvn package runtime jar — pom.xml uses <packaging>pom</packaging> so it doesn't emit a runnable jar; called out in the PR description. The Gradle jar is what was tested.
• One small plan correction: the Topic POJO actually serializes as subjectName / subjectDescription (not name / description). I adjusted the assertions accordingly during execution. T5/T6 verified the real JSON contract.

Devin session: https://app.devin.ai/sessions/9025b18a88794071956d8a9761324e2b