# Send Java to your agent
Hand the extracted package to your coding agent with a concrete install brief instead of figuring it out manually.
## Fast path
- Download the package from Yavira.
- Extract it into a folder your agent can access.
- Paste one of the prompts below and point your agent at the extracted folder.
## Suggested prompts
### New install

```text
I downloaded a skill package from Yavira. Read SKILL.md from the extracted folder and install it by following the included instructions. Tell me what you changed and call out any manual steps you could not complete.
```
### Upgrade existing

```text
I downloaded an updated skill package from Yavira. Read SKILL.md from the extracted folder, compare it with my current installation, and upgrade it while preserving any custom configuration unless the package docs explicitly say otherwise. Summarize what changed and any follow-up checks I should run.
```
## Machine-readable fields
```json
{
  "schemaVersion": "1.0",
  "item": {
    "slug": "java",
    "name": "Java",
    "source": "tencent",
    "type": "skill",
    "category": "开发工具",
    "sourceUrl": "https://clawhub.ai/ivangdavila/java",
    "canonicalUrl": "https://clawhub.ai/ivangdavila/java",
    "targetPlatform": "OpenClaw"
  },
  "install": {
    "downloadUrl": "/downloads/java",
    "sourceDownloadUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=java",
    "sourcePlatform": "tencent",
    "targetPlatform": "OpenClaw",
    "packageFormat": "ZIP package",
    "primaryDoc": "SKILL.md",
    "includedAssets": [
      "SKILL.md",
      "classes.md",
      "collections.md",
      "concurrency.md",
      "generics.md",
      "jvm.md"
    ],
    "downloadMode": "redirect",
    "sourceHealth": {
      "source": "tencent",
      "slug": "java",
      "status": "healthy",
      "reason": "direct_download_ok",
      "recommendedAction": "download",
      "checkedAt": "2026-05-04T11:56:33.333Z",
      "expiresAt": "2026-05-11T11:56:33.333Z",
      "httpStatus": 200,
      "finalUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=java",
      "contentType": "application/zip",
      "probeMethod": "head",
      "details": {
        "probeUrl": "https://wry-manatee-359.convex.site/api/v1/download?slug=java",
        "contentDisposition": "attachment; filename=\"java-1.0.1.zip\"",
        "redirectLocation": null,
        "bodySnippet": null,
        "slug": "java"
      },
      "scope": "item",
      "summary": "Item download looks usable.",
      "detail": "Yavira can redirect you to the upstream package for this item.",
      "primaryActionLabel": "Download for OpenClaw",
      "primaryActionHref": "/downloads/java"
    },
    "validation": {
      "installChecklist": [
        "Use the Yavira download entry.",
        "Review SKILL.md after the package is downloaded.",
        "Confirm the extracted package contains the expected setup assets."
      ],
      "postInstallChecks": [
        "Confirm the extracted package includes the expected docs or setup files.",
        "Validate the skill or prompts are available in your target agent workspace.",
        "Capture any manual follow-up steps the agent could not complete."
      ]
    }
  },
  "links": {
    "detailUrl": "https://openagent3.xyz/skills/java",
    "downloadUrl": "https://openagent3.xyz/downloads/java",
    "agentUrl": "https://openagent3.xyz/skills/java/agent",
    "manifestUrl": "https://openagent3.xyz/skills/java/agent.json",
    "briefUrl": "https://openagent3.xyz/skills/java/agent.md"
  }
}
```
## Documentation

### Quick Reference

TopicFileNulls, Optional, autoboxingnulls.mdCollections and iteration trapscollections.mdGenerics and type erasuregenerics.mdConcurrency and synchronizationconcurrency.mdClasses, inheritance, memoryclasses.mdStreams and CompletableFuturestreams.mdTesting (JUnit, Mockito)testing.mdJVM, GC, modulesjvm.md

### Critical Rules

== compares references, not content — always use .equals() for strings
Override equals() must also override hashCode() — HashMap/HashSet break otherwise
Optional.get() throws if empty — use orElse(), orElseGet(), or ifPresent()
Modifying while iterating throws ConcurrentModificationException — use Iterator.remove()
Type erasure: generic type info gone at runtime — can't do new T() or instanceof List<String>
volatile ensures visibility, not atomicity — count++ still needs synchronization
Unboxing null throws NPE — Integer i = null; int x = i; crashes
Integer == Integer uses reference for values outside -128 to 127 — use .equals()
Try-with-resources auto-closes — implement AutoCloseable, Java 7+
Inner classes hold reference to outer — use static nested class if not needed
Streams are single-use — can't reuse after terminal operation
thenApply vs thenCompose — compose for chaining CompletableFutures
Records are implicitly final — can't extend, components are final
serialVersionUID mismatch breaks deserialization — always declare explicitly
## Trust
- Source: tencent
- Verification: Indexed source record
- Publisher: ivangdavila
- Version: 1.0.1
## Source health
- Status: healthy
- Item download looks usable.
- Yavira can redirect you to the upstream package for this item.
- Health scope: item
- Reason: direct_download_ok
- Checked at: 2026-05-04T11:56:33.333Z
- Expires at: 2026-05-11T11:56:33.333Z
- Recommended action: Download for OpenClaw
## Links
- [Detail page](https://openagent3.xyz/skills/java)
- [Send to Agent page](https://openagent3.xyz/skills/java/agent)
- [JSON manifest](https://openagent3.xyz/skills/java/agent.json)
- [Markdown brief](https://openagent3.xyz/skills/java/agent.md)
- [Download page](https://openagent3.xyz/downloads/java)