| 1 | /* |
| 2 | * @(#) $Id: SluggishProcess.java,v 1.1.1.1 2006/03/19 06:09:42 rossen Exp $ |
| 3 | * |
| 4 | * Copyright (c) 2006, WebHydra.com |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions are met: |
| 9 | * |
| 10 | * * Redistributions of source code must retain the above copyright notice, |
| 11 | * this list of conditions and the following disclaimer. |
| 12 | * * Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * * Neither the name of the WebHydra.com nor the names of its contributors |
| 16 | * may be used to endorse or promote products derived from this software |
| 17 | * without specific prior written permission. |
| 18 | * |
| 19 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| 20 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 21 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 22 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| 23 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 24 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 25 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 26 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 27 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 28 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 29 | * POSSIBILITY OF SUCH DAMAGE. |
| 30 | */ |
| 31 | |
| 32 | package com.webhydra.slug.process; |
| 33 | |
| 34 | import javax.servlet.http.HttpSession; |
| 35 | |
| 36 | /** |
| 37 | * SluggishProcess - Extend this process and implement its execute() method in |
| 38 | * order to implement a SluggishProcess. |
| 39 | * @author rossen |
| 40 | */ |
| 41 | public abstract class SluggishProcess implements Runnable |
| 42 | { |
| 43 | /** |
| 44 | * Holds value of property status. |
| 45 | */ |
| 46 | private ProcessStatus status; |
| 47 | |
| 48 | /** |
| 49 | * Getter for property status. |
| 50 | * @return Value of property status. |
| 51 | */ |
| 52 | public synchronized ProcessStatus getProcessStatus() |
| 53 | { |
| 54 | return this.status; |
| 55 | } |
| 56 | |
| 57 | /** |
| 58 | * Setter for property status. |
| 59 | * @param status New value of property status. |
| 60 | */ |
| 61 | public synchronized void setProcessStatus(ProcessStatus status) |
| 62 | { |
| 63 | this.status = status; |
| 64 | } |
| 65 | |
| 66 | /** |
| 67 | * Interface implementation. |
| 68 | */ |
| 69 | public void run() { |
| 70 | try |
| 71 | { |
| 72 | ProcessStatus status = preExecute(); |
| 73 | setProcessStatus(status); |
| 74 | status = execute(); |
| 75 | setProcessStatus(status); |
| 76 | status = postExecute(); |
| 77 | setProcessStatus(status); |
| 78 | } |
| 79 | catch (Throwable t) |
| 80 | { |
| 81 | t.printStackTrace(); |
| 82 | setProcessStatus(new ProcessStatus(Status.FAILED, t.getMessage())); |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * Application defined method responsible for the long lasting action or series of actions. |
| 88 | * @return Updated ProcessStatus |
| 89 | * @exception Exception arbitrary exception. |
| 90 | */ |
| 91 | public abstract ProcessStatus execute() throws Exception; |
| 92 | |
| 93 | /** |
| 94 | * Iteaction point allowing cancelation of a process. |
| 95 | * Default implementation only changes PoressStaus property. |
| 96 | * Override this methid if you can provide real process interruption and cancelation. |
| 97 | */ |
| 98 | public void cancel() |
| 99 | { |
| 100 | setProcessStatus(new ProcessStatus(Status.CANCELED, "Canceled!")); |
| 101 | } |
| 102 | |
| 103 | /** |
| 104 | * Provides pre execution hook for process customization. |
| 105 | * Default implementation only changes ProcessStatus to <code>Status.RUNNING</code> |
| 106 | * @return Returns updated ProcessStatus. |
| 107 | */ |
| 108 | public ProcessStatus preExecute() |
| 109 | { |
| 110 | return new ProcessStatus(Status.RUNNING,"Started..."); |
| 111 | } |
| 112 | |
| 113 | /** |
| 114 | * Provides post execution hook for process customization. |
| 115 | * Default implementation only changes ProcessStatus to <code>Status.COMPLETED</code> |
| 116 | * if curren status is <code>Status.RUNNING</code>. Any other status is preserved unchanged. |
| 117 | * @return Updated PorcessStatus |
| 118 | */ |
| 119 | public ProcessStatus postExecute() |
| 120 | { |
| 121 | if (getProcessStatus() == null) |
| 122 | { |
| 123 | return new ProcessStatus(Status.FAILED, "Execution status not provided!"); |
| 124 | } |
| 125 | return (getProcessStatus().getStatus() == Status.RUNNING) ? |
| 126 | new ProcessStatus(Status.COMPLETED,"Done.") : getProcessStatus(); |
| 127 | } |
| 128 | |
| 129 | } |