DefaultMVCWorkflow.java

/*
` * Copyright (c) 2001-2016, Inversoft Inc., All Rights Reserved
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 */
package org.primeframework.mvc.workflow;

import javax.servlet.ServletException;
import java.io.IOException;
import java.util.List;

import org.primeframework.mvc.ErrorException;
import org.primeframework.mvc.action.ActionInvocationWorkflow;
import org.primeframework.mvc.action.ActionMappingWorkflow;
import org.primeframework.mvc.action.result.ResultInvocationWorkflow;
import org.primeframework.mvc.content.ContentWorkflow;
import org.primeframework.mvc.message.MessageWorkflow;
import org.primeframework.mvc.parameter.ParameterWorkflow;
import org.primeframework.mvc.parameter.PostParameterWorkflow;
import org.primeframework.mvc.parameter.RequestBodyWorkflow;
import org.primeframework.mvc.parameter.URIParameterWorkflow;
import org.primeframework.mvc.scope.ScopeRetrievalWorkflow;
import org.primeframework.mvc.scope.ScopeStorageWorkflow;
import org.primeframework.mvc.security.SavedRequestWorkflow;
import org.primeframework.mvc.security.SecurityWorkflow;
import org.primeframework.mvc.validation.ValidationWorkflow;

import com.google.inject.Inject;
import static java.util.Arrays.asList;
import static java.util.Collections.singletonList;

/**
 * This class is the main entry point for the Prime MVC. It uses the workflows passed into the constructor in the order
 * they are passed in. It also catches {@link ErrorException} and then processes errors using a error workflow set. The
 * error set consists of the {@link ScopeStorageWorkflow} followed by the {@link ResultInvocationWorkflow}.
 *
 * @author Brian Pontarelli
 */
public class DefaultMVCWorkflow implements MVCWorkflow {
  private final ErrorWorkflow errorWorkflow;

  private final ExceptionHandler exceptionHandler;

  private final List<Workflow> workflows;

  @Inject
  public DefaultMVCWorkflow(SavedRequestWorkflow savedRequestWorkflow,
                            RequestBodyWorkflow requestBodyWorkflow,
                            StaticResourceWorkflow staticResourceWorkflow,
                            ActionMappingWorkflow actionMappingWorkflow,
                            MessageWorkflow messageWorkflow,
                            ScopeRetrievalWorkflow scopeRetrievalWorkflow,
                            URIParameterWorkflow uriParameterWorkflow,
                            ParameterWorkflow parameterWorkflow,
                            ContentWorkflow contentWorkflow,
                            PostParameterWorkflow postParameterWorkflow,
                            SecurityWorkflow securityWorkflow,
                            ValidationWorkflow validationWorkflow,
                            ActionInvocationWorkflow actionInvocationWorkflow,
                            ScopeStorageWorkflow scopeStorageWorkflow,
                            ResultInvocationWorkflow resultInvocationWorkflow,
                            ErrorWorkflow errorWorkflow,
                            ExceptionHandler exceptionHandler) {
    this.exceptionHandler = exceptionHandler;
    this.errorWorkflow = errorWorkflow;
    this.workflows = asList(savedRequestWorkflow, requestBodyWorkflow, staticResourceWorkflow, actionMappingWorkflow,
        messageWorkflow, scopeRetrievalWorkflow, uriParameterWorkflow, parameterWorkflow,
        contentWorkflow, postParameterWorkflow, securityWorkflow, validationWorkflow, actionInvocationWorkflow, scopeStorageWorkflow, resultInvocationWorkflow);
  }

  /**
   * Creates a sub-chain of the MVC workflows and invokes it.
   *
   * @param workflowChain The chain.
   * @throws IOException If the sub-chain throws an IOException
   * @throws ServletException If the sub-chain throws an ServletException
   */
  public void perform(WorkflowChain workflowChain) throws IOException, ServletException {
    try {
      WorkflowChain chain = new SubWorkflowChain(workflows, workflowChain);
      chain.continueWorkflow();
    } catch (RuntimeException | Error e) {
      exceptionHandler.handle(e);

      WorkflowChain errorChain = new SubWorkflowChain(singletonList(errorWorkflow), workflowChain);
      errorChain.continueWorkflow();
    }
  }
}