java-jdtls-mcp-server
Server Configuration
Describes the environment variables required to run the server.
| Name | Required | Description | Default |
|---|---|---|---|
| JDTLS_HOME | Yes | Path to JDT.LS installation root directory | |
| JDTLS_JAVA_HOME | No | Dedicated JDK path for JDT.LS (overrides JAVA_HOME). Defaults to system JAVA_HOME. | |
| JAVA_WORKSPACE_PATH | No | Root path of your Java project. Defaults to current working directory. | |
| JDTLS_JAVA_RUNTIMES | No | JSON list of Java Runtimes for different project versions | |
| JDTLS_MAVEN_OFFLINE | No | Enable Maven offline mode (true/false). Defaults to false. | |
| JDTLS_MAVEN_USER_SETTINGS | No | Path to custom Maven user settings.xml | |
| JDTLS_MAVEN_GLOBAL_SETTINGS | No | Path to custom Maven global settings.xml |
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 | {} |
Tools
Functions exposed to the LLM to take actions
| Name | Description |
|---|---|
| java_startA | Start the Java Language Server (JDT.LS). Required before other commands. If already running, it will restart. |
| java_restartB | Restart the Java Language Server (JDT.LS). |
| java_open_fileB | Notify the language server that a file is open (didOpen). |
| java_get_definitionB | Get definition location for a symbol. |
| java_get_referencesC | Get references for a symbol. |
| java_get_hoverB | Get hover information for a symbol. |
| java_get_diagnosticsA | Get diagnostics (errors/warnings) for a file. This tool now attempts to pull diagnostics actively from the server if supported (LSP 3.17+), otherwise falls back to cached results from asynchronous publishing. |
| java_get_workspace_diagnosticsA | Pull diagnostics for the entire workspace (LSP 3.17+). Note: This may not be supported by all language server versions. |
| java_load_maven_projectA | Load a Maven Java project into the language server workspace. This causes JDTLS to index the project, resolving dependencies and symbols across the entire project without needing to open files individually. |
| java_search_symbolsA | Search for symbols (classes, methods, fields) across the entire workspace by name. |
| java_get_file_symbolsB | Get all symbols (classes, methods, fields) defined in a specific file. |
| java_get_statusA | Get the current status of the Java Language Server. |
| configure_jdt_lsB | Dynamically update JDT.LS configuration (e.g. enable source downloading). |
| find_referencesA | Find references for a symbol. This is an enhanced version of java_get_references that marks external library results. |
| read_java_contentA | Read the content of a Java file, including local files and external library source code (jdt:// or jrt:// URIs). |
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 15 tools
Most tools have distinct purposes, but 'find_references' and 'java_get_references' are very similar and could cause confusion. 'java_get_diagnostics' and 'java_get_workspace_diagnostics' also overlap somewhat. Overall, descriptions help differentiate, but ambiguity exists.
The majority of tools follow the 'java_verb_noun' pattern (12 out of 15). However, 'configure_jdt_ls', 'find_references', and 'read_java_content' deviate from this convention, breaking perfect consistency.
15 tools is well-scoped for a Java language server integration. The set covers key operations like startup, diagnostics, symbol queries, references, and project loading without being overly large or trivial.
The tool set covers common LSP operations (hover, definition, references, diagnostics, symbols) and includes workspace-level diagnostics. Missing features like code completion, formatting, or rename, but the set is sufficient for typical agent interactions with JDT LS.