salesforce-case-attachment.java

public String createAttachment(String caseId, String path, String filename) throws Exception {
		Path file = Paths.get(path);
		byte[] data = Files.readAllBytes(file);

		JSONObject obj = new JSONObject();
		obj.put("ParentId", caseId);
		obj.put("Name", filename);
		obj.put("body", new String(Base64.encodeBase64(data)));

		List<JSONObject> response = doPost("Attachment", obj.toString());
		String documentId = "";
		if(response.size() > 0) {
			JSONObject result = response.get(0);
			if(result.getBoolean("success")) {
				documentId = (String) result.getString("id");
			}
		}
		return documentId;
	}