src/main/java/org/eclipse/openk/elogbook/auth2/util/JwtHelper.java

/**
******************************************************************************
* Copyright © 2017-2018 PTA GmbH.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* 
*     http://www.eclipse.org/legal/epl-v10.html
* 
******************************************************************************
*/
package org.eclipse.openk.elogbook.auth2.util;

import com.google.gson.JsonSyntaxException;
import com.google.gson.reflect.TypeToken;
import org.apache.commons.codec.binary.Base64;
import org.apache.log4j.Logger;
import org.eclipse.openk.elogbook.auth2.model.JwtPayload;
import org.eclipse.openk.elogbook.auth2.model.KeyCloakUser;
import org.eclipse.openk.elogbook.common.JsonGeneratorBase;
import org.eclipse.openk.elogbook.exceptions.BtbInternalServerError;

import java.lang.reflect.Type;
import java.util.List;

public class JwtHelper {

  private static final Logger LOGGER = Logger.getLogger(JwtHelper.class.getName());

  private JwtHelper() {}

  public static JwtPayload getJwtPayload(String token) {

    String plainToken = JwtHelper.formatToken(token);
    String[] parts = plainToken.split("[.]");


    String jwtPayload = parts[1]; // we need only this here

    Base64 decoder = new Base64(true);
    byte[] decodedBytes = decoder.decode(jwtPayload);
    jwtPayload = new String(decodedBytes);

    return getJwtPayloadFromJson(jwtPayload);
  }

  public static JwtPayload getJwtPayloadFromJson(String json) {
    JwtPayload jwtPayload = JsonGeneratorBase.getGson().fromJson(json, JwtPayload.class);
    return JsonGeneratorBase.getGson().fromJson(json, JwtPayload.class);
  }

  public static List<KeyCloakUser> getUserListFromJson(String json) throws BtbInternalServerError {
    try {
      Type listType = new TypeToken<List<KeyCloakUser>>(){}.getType();
      return JsonGeneratorBase.getGson().fromJson(json, listType);
    } catch (JsonSyntaxException ex) {
      LOGGER.error("Error in getUserListFromJson", ex);
      throw new BtbInternalServerError("JsonSyntaxException");
    }
  }

  public static String formatToken(String accessToken) {
    return accessToken != null ? accessToken.replace("Bearer", "").trim() : "";
  }
}