java-to-type

Convert Java POJO / enum / Spring controller source files to JSDoc or TypeScript type definitions — a lightweight alternative to protobuf for teams that need front-end types from a Java back-end without an IDL layer.

It is aimed at legacy or non-standardized Java back-ends that have no OpenAPI/Swagger contract and no shared schema layer. Instead of hand-mirroring types on the front end, it parses the business data structures directly from the Java source and gives you a semi-automated type layer — the practical effect of a protobuf middle layer, without asking the back-end to change anything.

Install

npm i -D @tonylua/java-to-type

Usage

const { parseDir, parseJava } = require('@tonylua/java-to-type')

// directory
const results = parseDir('/path/to/java', { parserMeta: { apiPrefix: '/api' } })

// single file
const results = parseJava(fs.readFileSync('MyPojo.java', 'utf8'), 'MyPojo.java')

See samples/buildJSDoc.ts and samples/buildJSDocWithTS.ts for full examples.

Options

parseDir(dir, option?) / parseJava(code, path, option?)

| option | type | description | |--------|------|-------------| | isEnum | boolean | force enum/constant parser | | excludePaths | string[] | skip files containing these strings | | parserMeta.outputTS | boolean | emit TypeScript instead of JSDoc | | parserMeta.apiPrefix | string | prepend to service URLs | | parserMeta.jsDocServiceRequestInstanceName | string | HTTP client name (default request) | | parserMeta.jsDocServiceTopImport | string | import line at top of service output |

Dev

npm run build          # compile
npm run examples       # JSDoc sample
npm run examples:withTS  # TypeScript sample
npm test               # snapshot tests
npm run test:u         # update snapshots

Supported

• POJO → @typedef / export type
  • nested static classes (each emitted as its own type)
  • Java record
  • Lombok @Data / @Getter / @Setter
  • generics (List<T> → Array.<T> / T[], Map<K,V> → Object)
  • @NotNull marks a property required
• enum (incl. multi-arg constructors like OK("0", "正常")) → @enum / export enum
• static final constants → @enum / export enum
• Spring @RestController with @GetMapping, @PostMapping, @RequestMapping(method=...), @PathVariable, @RequestBody, @RequestHeader, generic return types → typed request functions (JSDoc and TypeScript)

Requires valid Java syntax. Files with syntax errors are skipped.