1. Introduction

In this tutorial, we will retrieve metadata and binary content of a DMS object of which we know the value for system:objectId.

2. Requirements

Please work through the following tutorials to get prepared:

3. Java Libraries

Import the following Java libraries (if not already done).

Used Java Libraries
import okhttp3.*;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.CookieManager;
import java.net.CookiePolicy;
import java.util.Base64;

4. Variables with Login and Content Types Configuration

Specify your access credentials and content type configurations (if not already done).

Specify the objectId variable.

Definition of Variables
public static final String username = "root";
public static final String userpassword = "changeme";
public static final String auth = "Basic "+ Base64.getEncoder().encodeToString((username+":"+userpassword).getBytes());
public static final String tenant = "myfirsttenant";
public static final String baseUrl = "http://123.456.78.9:30080";

public static final MediaType JSON = MediaType.parse("application/json; charset=utf-8");
public static final MediaType PLAINTEXT = MediaType.parse("text/plain; charset=utf-8");

public static final String objectId = "ecc0f6cc-7467-4e02-9903-073b893afdfd";

5. Client

To send our requests, we again use the Java client.

Client with Cookie Handling
try {
    CookieJar cookieJar = new JavaNetCookieJar(new CookieManager(null, CookiePolicy.ACCEPT_ALL));
    OkHttpClient client = new OkHttpClient.Builder().cookieJar(cookieJar).build();

} catch (Exception e) {
    e.printStackTrace();

}

5.1. Retrieving the Metadata

The direct access to the metadata of a DMS object is requested via the endpoint GET /api/dms/objects/{objectId}. The objectId serves as a unique identifier of the DMS object.

Retrieving Metadata of an Object
Request metadataRequest = new Request.Builder()
        .header("Authorization", auth)
        .header("X-ID-TENANT-NAME", tenant)
        .url(baseUrl+ "/api/dms/objects/" + objectId)
        .get().build();

Response response = client.newCall(metadataRequest).execute();
String responseString = response.body().string();
System.out.println(responseString);

The API call response will contain the current version of the objects' metadata in JSON format.

To retrieve the content of an object, a GET request is sent to the endpoint /api/dms/objects/{objectId}/contents/file. As we imported a plain text binary content file, we can download it in TXT format again. The result will be stored as downloaded_file.txt file in your project directory.

Retrieving Content of an Object
Request contentRequest = new Request.Builder()
            .header("Authorization", auth)
            .header("X-ID-TENANT-NAME", tenant)
            .url(baseUrl+ "/api/dms/objects/" + objectId + "/contents/file")
            .get().build();

Response contentResponse = client.newCall(contentRequest).execute();
InputStream in = contentResponse.body().byteStream();
FileOutputStream out = new FileOutputStream("downloaded_file.txt");
out.write(in.readAllBytes());

6. Summary

This tutorial showed how to use an OkHttpClient to retrieve documents via Core API.

Continue with Deleting Objects

Back to Tutorials Overview

A complete code example can be found in this Git repository.