Method Trace Log

Method Trace Log

Non-intrusive AOP method tracing + trace tree + alerting for Spring Boot. Includes a standalone MCP server (methodTraceLog-mcp) that exposes the same capabilities to AI agents over stdio.

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Features

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Quick Start

Add the dependency

<dependency>
    <groupId>io.github.wb04307201</groupId>
    <artifactId>methodTraceLog-spring-boot-starter</artifactId>
    <version>1.1.0</version>
</dependency>

Minimal configuration

method-trace-log:
  log:
    enable: true
  file:
    enable: true
    path: ./logs
  security:
    api-key: change-me-in-production   # required in production; empty disables auth (dev only)

management:
  endpoints:
    web:
      exposure:
        include: methodtrace           # for the /actuator/methodtrace panel data

Open the panel

http://localhost:8080/methodTraceLog/panel — single page with 4 tabs: 概览 (overview) / 调用记录 (trace search + export) / 日志文件 (file viewer + real-time tail) / 反编译 (CFR decompile).

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Configuration Reference

method-trace-log:
  log:
    enable: true                                  # AOP master switch
    sample-rate: 1.0                              # 0.0 ~ 1.0; child spans inherit parent decision (clamped on startup)
    exclude-patterns: []                          # method-name blacklist (case-insensitive equals match); hit → proceed() directly, no events emitted. e.g. [equals, hashCode, toString, canEqual]
    service-calls:                                # start-up enable flags
      - { name: CustomLog,         enable: false }   # built-in services: SimpleLogService / SimpleMonitorService / AlertingService / CustomLog
    trace-store:                                  # where the in-memory tree lives
      type: in-memory                             # in-memory | file | none
      path: ./trace-store                         # only when type=file (auto-creates yyyy-MM-dd subdirs)
      max-traces: 1000                            # recent map cap (in-memory & file memory cache)
      ttl-millis: 28800000                        # 8h; clean() drops disk files older than this
      rebuild-index-on-start: false               # type=file only; rebuilds traceId→file index at startup (slows boot on large dirs)
  file:
    enable: true
    path: ./logs
    allowed-extensions: [.log, .txt, .out]
    scan-lines: 10000                             # stream-scan line cap; Files.lines() + limit() is lazy, so the file itself can be arbitrarily large — no size check
    max-file-size: 100MB                          # per-file size cap (default; set to 0/null = no limit)
    total-size-cap: 10GB                          # cumulative cap across all rolled files in the dir
    # log-pattern: (\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}\.\d{3})\s+\[([^\]]+)\]\s+(\w+)\s+([^\s]+)\s*-\s*(.*)
  security:
    api-key: change-me-in-production              # empty = no auth
    session:
      ttl-millis: 28800000                        # 8h sliding session for browser cookies
    cors:                                         # CORS for browser panels on different origins (opt-in: empty allowed-origins = disabled)
      allowed-origins: []                         # ["https://your-panel.example.com"]; ["*"] = all (incompatible with credentials)
      allowed-methods: [GET, POST, OPTIONS, DELETE, PUT]
      allowed-headers: [Content-Type, X-Api-Key, Authorization]
      allow-credentials: false                    # true requires allowed-origins NOT be "*"
      max-age: 0                                  # preflight cache seconds (0 = always re-validate)
  decompile:
    timeout-seconds: 10                           # CFR daemon-thread timeout
  otel:                                           # requires opentelemetry-sdk on classpath
    enable: false
    endpoint: http://localhost:4318/v1/traces
    service-name: method-trace-log
    service-namespace: ""                        # Resource service.namespace label
    export-delay-millis: 5000                    # OTLP client built-in batching delay
    max-queue-size: 2048
    max-export-batch-size: 512
    export-timeout-millis: 30000
  propagate:                                      # W3C traceparent propagation
    http-inbound: true                            # TraceContextFilter reads traceparent
    rest-client-outbound: true                    # RestClient.Builder interceptor
    rest-template-interceptor: true               # exposes a RestTemplate interceptor bean
  alerting:                                       # exception alerting — opt-in; off by default
    enable: false                                 # true registers AlertingService as an ICallService
    webhook-url: ""                               # empty = log only; non-empty POSTs events (best-effort, async)
    threshold:
      error-count: 10                             # errors per class#method within window to fire
      window-seconds: 60                          # sliding-window length
    cooldown-seconds: 300                         # suppress repeat alerts for the same key
    classes: []                                   # whitelist prefix list; empty = alert on every class

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HTTP Surface

All routes require X-Api-Key (or MTRACE_SESSION cookie) when security.api-key is non-empty, except /methodTraceLog/panel (HTML).

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MDC Trace IDs

LogAspect puts traceid / spanid / pspanid into SLF4J MDC. Use them in your logback pattern to correlate logs across the call chain:

<pattern>%d{HH:mm:ss.SSS} [%thread] [trace=%X{traceid} span=%X{spanid}] %-5level %logger - %msg%n</pattern>

For HTTP boundaries, TraceContextFilter reads traceparent on the way in, and the RestClient interceptor writes it on the way out — upstream and downstream traceids join automatically.

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Web Panel Authentication

When security.api-key is non-empty, the panel UI uses a top banner (not a modal) to collect the API Key:

• Banner is shown above the tab content the first time you visit /methodTraceLog/panel without a valid session.
• Submitting a valid Key (button or Enter) hides the banner, sets the MTRACE_SESSION cookie, and auto-loads the current tab's data — no manual refresh.
• Wrong / empty Key shows an inline error (请输入 API Key / ❌ API Key 无效或鉴权未启用).
• Session is a sliding 8-hour cookie (security.session.ttl-millis, default 28 800 000). It renews on use, so you only re-enter the Key after 8h of inactivity or after clicking the 🚪 注销 button.
• The logout button only appears in the header when a session is active; the /methodTraceLog/logout endpoint invalidates the cookie and re-mounts the banner.
• In dev mode (api-key: ""), the banner is suppressed entirely and no logout button is shown.

GET /methodTraceLog/session/status returns { authEnabled, sessionValid } so the panel JS can decide whether to show the banner. While the banner is up, the in-page mtlFetch queues 401 responses and replays them on successful login, so the user never sees an "unauthorized" toast during the login flow.

CLI / MCP clients should keep using the X-Api-Key header directly — the cookie session is purely a browser convenience.

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@AspectLog Annotation

Method-level opt-in (the class doesn't have to be a @Component). Use it to rename the method in the trace tree and on the OTel span:

public class MyHelper {
    @AspectLog("do-something")
    public void doSomething(String s) { ... }
}

The trace list and OTel span name will show do-something instead of the raw method signature.

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Custom ICallService

Extend AbstractCallService and implement consumer(ServiceCallInfo). It's auto-picked up by the CallServiceStrategy:

@Component
public class MyService extends AbstractCallService {

    @Override
    public void consumer(ServiceCallInfo info) {
        // logActionEnum is one of BEFORE / AFTER_RETURN / AFTER_THROW
        log.info("{} {}", info.getClassName(), info.getMethodName());
    }

    @Override public String getCallServiceName() { return "MyService"; }
    @Override public String getCallServiceDesc() { return "My desc"; }
}

Start it disabled: service-calls: [{ name: MyService, enable: false }], then flip via the panel.

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MCP Server

A separate, standalone Spring Boot process that speaks Model Context Protocol over stdio. It forwards @Tool calls to one or more hosts (each host = an app that has the starter on the classpath) over HTTP.

MCP server config (mcpServers JSON block) for AI clients like Claude Desktop, Cursor, Cline:

{
  "mcpServers": {
    "sql-forge-mcp": {
      "command": "jbang.cmd",
      "args": [
        "io.github.wb04307201:methodTraceLog-mcp:1.1.0",
        "--method-trace-log.mcp.hosts[0].name=local-dev",
        "--method-trace-log.mcp.hosts[0].url=http://localhost:8080",
        "--method-trace-log.mcp.hosts[0].description=Local dev",
        "--method-trace-log.mcp.hosts[0].api-key=change-me-in-production"
      ]
    }
  }
}

15 tools exposed: getHosts, ping, getCallServices, setCallServiceEnable, getMethodTraceList, getMethodTraceByTraceId, getAlerts, getSlowMethods, decompileMethod, getLogFiles, queryLogContent, downloadLog, startMonitor, stopMonitor, getMonitorStatus.

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Gotchas

• LogAspect exclusions: framework-internal types (ICallService, MethodTraceLogEndPoint, LogFileService, LogFileRealTimeService) are excluded. Add yours to the pointcut if you have similar internal beans.
• Path traversal: FileUtils.pathInspection is the whitelist for LogFileService and LogFileRealTimeService — [a-zA-Z0-9._-]+, no .., ≤ 255 chars.
• Log pattern: the default log-pattern only matches the standard logback pattern. If you change <pattern> in logback.xml, update log-pattern in YAML or LogLineInfo.parse will not split keyword / level / time.
• CFR resources: decompile reads class bytes through the classloader's getResourceAsStream — works uniformly for file paths, thin jars, and Spring Boot fat-jar nested jars. Don't parse the URL.getPath() string.
• Spring Boot fat-jar: the test module does not declare spring-boot-maven-plugin. Use mvn package then java -cp target/classes;<classpath> cn.wubo.method.trace.log.MethodTraceLogTestApplication.
• Maven on this machine: invoke mvn as /c/developer/apache-maven-3.9.16/bin/mvn — the default mvn shim is broken.