jons-mcp-java
Server Configuration
Describes the environment variables required to run the server.
| Name | Required | Description | Default |
|---|---|---|---|
| JAVA_HOME | No | Java 21+ installation | Auto-detect |
| JDTLS_HOME | No | JDT.LS installation directory | Auto-detect |
| JONS_MCP_JAVA_WORKSPACE | No | Root workspace for Java projects | Current directory |
Instructions
Guidance the server publishes about itself, which clients place ahead of the tool catalog so the model reads it before choosing anything.
This server publishes no instructions, or was last inspected before Glama recorded them.
Capabilities
Features and capabilities supported by this server
Protocol revision2025-11-25
| Capability | Details |
|---|---|
| tools | {
"listChanged": true
} |
| logging | {} |
| prompts | {
"listChanged": false
} |
| resources | {
"subscribe": false,
"listChanged": false
} |
| extensions | {
"io.modelcontextprotocol/ui": {}
} |
| experimental | {} |
Tools
Functions exposed to the LLM to take actions
| Name | Description |
|---|---|
| diagnosticsC | Get fresh diagnostics for one Java file. |
| restart_serverA | Stop JDT.LS server(s) and clear runtime state. Servers restart lazily on the next file-backed tool call. |
| symbol_infoC | Get hover information for a symbol at the given position. |
| definitionC | Navigate to the definition of a symbol at the given position. |
| referencesC | Find all references to the symbol at the given position. |
| implementationB | Find implementations of an interface or abstract method. |
| type_definitionC | Navigate to the type definition of a symbol at the given position. |
| preview_renameC | Preview a symbol rename across the project without writing files. |
| document_symbolsC | Get all symbols defined in a Java file. |
| workspace_symbolsD | Search for symbols in an initialized project workspace. |
Prompts
Interactive templates invoked by user choice
| Name | Description |
|---|---|
No prompts | |
Resources
Contextual data attached and managed by the client
| Name | Description |
|---|---|
No resources | |
TDQS
Scored across 10 tools
Each tool targets a distinct operation (e.g., definition, references, diagnostics). The slight overlap between definition and type_definition is clarified by their descriptions, and all tools have clear boundaries.
All tool names follow a consistent lowercase_snake_case pattern using descriptive nouns (e.g., definition, references) or verb_actions (preview_rename). No mixing of conventions.
10 tools is well within the ideal range for a focused Java language server. Each tool serves a distinct purpose without unnecessary bloat or deficiency.
Covers navigation, search, diagnostics, and rename preview. Missing an actual rename apply tool and code completion, but the core workflow for symbol analysis is well-supported.