1 /* 2 * Copyright 1999-2001,2004 The Apache Software Foundation. 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package org.apache.commons.workflow; 18 19 20 /** 21 * <p>A <strong>Step</strong> represents a single executable action that 22 * can occur during the completion of an Activity. The dynamic execution 23 * of the implementation of this Step happens within the <code>execute()</code> 24 * method -- everything else about a Step is part of its static definition, 25 * which is shared among all users of the owning Activity.</p> 26 * 27 * @version $Revision: 155475 $ $Date: 2005-02-26 13:31:11 +0000 (Sat, 26 Feb 2005) $ 28 * @author Craig R. McClanahan 29 */ 30 31 public interface Step { 32 33 34 // ------------------------------------------------------------- Properties 35 36 37 /** 38 * Return the unique identifier (within this Activity) of this Step. 39 */ 40 public String getId(); 41 42 43 /** 44 * Set the unique identifier (within this Activity) of this Step. 45 * 46 * @param id The new unique identifier 47 */ 48 public void setId(String id); 49 50 51 /** 52 * Return the next Step in our associated Activity or Block. 53 */ 54 public Step getNextStep(); 55 56 57 /** 58 * Set the next Step in our associated Activity or Block. 59 * 60 * @param nextStep The new next Step 61 */ 62 public void setNextStep(Step nextStep); 63 64 65 /** 66 * Return the Activity or Block that owns this Step. 67 */ 68 public Owner getOwner(); 69 70 71 /** 72 * Set the Activity or Block that owns this Step. 73 * 74 * @param owner The new owning Activity or Block 75 */ 76 public void setOwner(Owner owner); 77 78 79 /** 80 * Return the previous Step in our associated Activity or Block. 81 */ 82 public Step getPreviousStep(); 83 84 85 /** 86 * Set the previous Step in our associated Activity or Block. 87 * 88 * @param previousStep The new previous Step 89 */ 90 public void setPreviousStep(Step previousStep); 91 92 93 // --------------------------------------------------------- Public Methods 94 95 96 /** 97 * Perform the executable actions related to this Step, in the context of 98 * the specified Context. 99 * 100 * @param context The Context that is tracking our execution state 101 * 102 * @exception StepException if a processing error has occurred 103 */ 104 public void execute(Context context) throws StepException; 105 106 107 }