tomcon / tika-server-1

Apache Tika Server as a Background Service in Node.js

Tika-Server

Apache Tika Server as a Background Service in Node.js

About

This is a small JavaScript library for use in Node.js environments, providing the possibility to run Apache Tika Server as a local background service and query it through a frontend JavaScript API.

NOTICE

The Apache Tika Server is written in Java and hence this Node.js modules requires an installed java executable in the environment.

Installation

$ npm install tika-server

Usage

const TikaServer = require("tika-server")

;(async () => {
    const ts = new TikaServer()
    ts.on("debug", (msg) => {
        console.log(`DEBUG: ${msg}`)
    })
    await ts.start()
    await ts.queryText("foo").then((data) => {
        console.log(data)
    })
    await ts.stop()
})().catch((err) => {
    console.log(`ERROR: ${err}`)
})

Application Programming Interface

declare class TikaServer {
    constructor(options?: {
        javaBinary?: string   /* default: "java" */
        javaOptions?: string  /* default: "-server -Xms1G -Xmx1G" */
        tikaBinary?: string   /* default: "${__dirname}/tika-server-cli.jar" */
        tikaConfig?: string   /* default: "${__dirname}/tika-server-cli.xml" */
        tikaOptions?: string  /* default: "--log info" */
        tikaHost?: string     /* default: "127.0.0.1" */
        tikaPortMin?: number  /* default: 41000 */
        tikaPortMax?: number  /* default: 42000 */
    })

    public on(
        event: string,
        callback: (event: any) => void
    ): void

    public start(
    ): Promise<void>

    public query(
        content: any,
        options?: {
            endpoint?: string  /* default: "tika" */
            type?: string      /* default: "application/octet-stream" */
            accept?: string    /* default: "text/xml" */
            response?: string  /* default: "blob" */
            filename?: string  /* default: "" */
        }
    ): Promise<any>

    public queryMeta(
        content: any,
        options?: {
            type?: string      /* default: "application/octet-stream" */
            filename?: string  /* default: "" */
        }
    ): Promise<object>

    public queryText(
        content: any,
        options?: {
            type?: string      /* default: "application/octet-stream" */
            filename?: string  /* default: "" */
        }
    ): Promise<string>

    public stop(
    ): Promise<void>
}

Motivation

The major differences of tika-server to similar NPM modules and the motivation for the existence of tika-server are:

1. tika-server, in contrast to the tika module, does not depend on the native java module. Instead, it just requires the java executable to be available.

2. tika-server, in contrast to the tika module, does not spawn Apache Tika for every query. Instead, it uses a continuously running Apache Tika Server in a background process.

3. tika-server, in contrast to the tika module, does not ship with an old Tika JAR. Instead, it automatically downloads and uses a more recent one.

4. tika-server, in contrast to the tika-server-client module, does not need a pre-installed Apache Tika Server. Instead, it automatically starts and stops a local instance of it in the background.

5. tika-server, in contrast to the tika-text-extract module, does not use the hard-coded (default) TCP/IP port 9998 for the background Apache Tika Server process. Instead, it automatically determines and uses a free TCP/IP port on localhost.

License

Copyright (c) 2018-2021 Dr. Ralf S. Engelschall (http://engelschall.com/)

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.