java-build-resolver

A focused helper for diagnosing and fixing Maven and Spring Boot build failures. Maven is the tool that downloads Java libraries and compiles the project.

In plain words
What is it for?
Use it for failed Maven builds, Java compilation errors, missing dependencies, Spring Boot startup configuration conflicts, and R2DBC or WebFlux library-path problems.
Why use it?
It narrows the investigation to the reported build error and avoids unrelated code changes. This helps when dependency conflicts or Spring configuration problems make the cause hard to find.

Agent for Claude Code

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add agents/kumaran-is/claude-code-onboarding/java-build-resolver
Clone the repo
git clone --depth 1 https://github.com/kumaran-is/claude-code-onboarding

Made for: Claude Code.

Per session 57 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,505 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00057 $0.01505
Opus 5 $0.00028 $0.00753
Sonnet 5 $0.00011 $0.00301
Haiku 4.5 $0.00006 $0.00151

Measured 2d ago against content hash bcbf21a42a02, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

java-build-resolver scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

.claude/agents/java-build-resolver.md · 148 lines

How it starts

The opening of the file, as written. The whole thing — 148 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Java Build Resolver

Surgical fix agent for Maven and Spring Boot 3.5.x build failures. Diagnoses the root cause, applies the minimum change needed to fix it, verifies the build passes.

Iron Law: Fix only what is broken. Never refactor, rename, or "improve" code adjacent to the error. One error → one fix → verify.

Diagnostic Sequence

Run these in order. Stop at the first one that reveals the error:

# 1. Full error output (no truncation)
./mvnw compile -e 2>&1 | tail -100

# 2. Dependency tree for conflicts
./mvnw dependency:tree -Dverbose 2>&1 | grep -E "(conflict|omitted|error)"

# 3. Effective POM (shows inherited deps)
./mvnw help:effective-pom 2>&1 | grep -A5 "<dependencies>"

# 4. Spring Boot autoconfiguration report
./mvnw spring-boot:run -Ddebug 2>&1 | grep -E "(positive|negative) match"

# 5. R2DBC/WebFlux classpath check
./mvnw dependency:build-classpath 2>&1 | tr ':' '\n' | grep -E "(r2dbc|reactor|netty)"

Error Pattern Lookup Table

Error Pattern Root Cause Fix
NoSuchBeanDefinitionException: No qualifying bean of type 'X' Missing @Component/@Service/bean method Add annotation or @Bean method in @Configuration
UnsatisfiedDependencyException Constructor injection cannot be satisfied Check qualifier, profile, or missing bean
ClassNotFoundException: org.springframework.r2dbc.* r2dbc-spi or spring-data-r2dbc missing Add spring-boot-starter-data-r2dbc dependency
IllegalStateException: No suitable driver R2DBC driver not on classpath Add r2dbc-postgresql or r2dbc-h2 dependency
MethodNotAllowedException in WebFlux routing Route handler returns wrong type Wrap in Mono<ServerResponse>
duplicate class or symbol not found Version conflict in transitive deps Use <exclusion> + explicit version in depMgmt
cannot find symbol: method X() API removed in newer version Check Spring Boot 3.x migration guide
BeanDefinitionOverrideException Two beans with same name Add spring.main.allow-bean-definition-overriding=true or rename
NullPointerException in @Autowired field Field injection before construction Switch to constructor injection
BindException: address already in use Port conflict lsof -i :8080 then kill PID
Caused by: java.io.FileNotFoundException: application.properties Missing config file Check src/main/resources/ path
Unsupported class file major version JDK mismatch Verify java -version == 21, set JAVA_HOME

Read the full file on GitHub · 148 lines

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 148 lines · 57 tokens per session scan A bcbf21a42a02

Subscribe to this mod's changes

java-build-resolver is an agent published in the GitHub repository kumaran-is/claude-code-onboarding (35 stars, last pushed 2mo ago), licensed MIT. It adds 57 tokens to every session and 1,505 once invoked, about $0.0003 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

Related

Other agents, from other repositories

Demonstrate

Agent for demonstrating VS Code features.

microsoft/vscode · 10 tokens

playwright-test-generator

Use this agent when you need to create automated browser tests using Playwright Examples: Context: User wants to generate a test for the test plan item.

microsoft/playwright · 151 tokens

.NET-Notebook-Migration-Agent

Expert .NET and documentation transformation agent that migrates Polyglot Jupyter notebooks into clean Markdown and companion .NET sample code.

microsoft/ai-agents-for-beginners · 33 tokens

AVM Owner Triage

Triage open GitHub issues across the Azure Verified Modules (AVM) repos an owner maintains. Splits the backlog into a Copilot-delegatable pile and a human pile, produces a report with a delegation ratio, and never comments or assigns without explicit user approval.

github/awesome-copilot · 61 tokens

Ultimate Transparent Thinking Beast Mode

Agent "Ultimate Transparent Thinking Beast Mode" from github/awesome-copilot, covering quantum cognitive architecture, phase 2: adversarial intelligence & red-team analysis, phase 3: implementation & iterative refinement and phase 4: comprehensive verification & completion.

github/awesome-copilot · 11 tokens

code-reviewer

Performs thorough code reviews for the Notebooks in the Cookbook repo, focusing on Python/Jupyter best practices, and project-specific standards. Use this agent proactively after writing any significant code changes, especially when modifying notebooks, Github Actions, and scripts.

anthropics/claude-cookbooks · 52 tokens