pi-lens/rules/tree-sitter-queries/java/resources-closed.yml

Real-time code feedback for pi — LSP, linters, formatters, type-checking, structural analysis & booboo

# Resources Closed
# Detects resources that should be closed (pre-Java 7 style)
id: resources-closed
name: Resources Should Be Closed
severity: error
category: reliability
defect_class: correctness
inline_tier: blocking
language: java

message: "Resource '{{RESOURCE}}' should be closed in finally block"

description: |
  Resources like streams, connections, and files must be closed
  to prevent leaks. Use try-with-resources (Java 7+) or close()
  in finally block.

  ✅ FIX: Use try-with-resources

  ```java
  try (InputStream in = new FileInputStream(file)) {  // GOOD
      // use stream
  }  // auto-closed
  ```

query: |
  (local_variable_declaration
    type: (type_identifier) @TYPE (#match? @TYPE "^(InputStream|OutputStream|Connection|Statement|ResultSet|Socket|Reader|Writer)$")
    (variable_declarator
      name: (identifier) @RESOURCE) @DECL)

metavars:
  - TYPE
  - RESOURCE
  - DECL

post_filter: not_closed_or_try_with_resources

tags:
  - reliability
  - java
  - leak
  - cert

examples:
  bad: |
    InputStream in = new FileInputStream(file);  // BAD - not closed
    // use stream
    // missing in.close() or try-with-resources

  good: |
    try (InputStream in = new FileInputStream(file)) {  // GOOD
        // use stream
    }

has_fix: true
fix_action: wrap_try_with_resources