01: /*
02: * Copyright (c) 2002-2006 by OpenSymphony
03: * All rights reserved.
04: */
05: package com.opensymphony.xwork;
06:
07: /**
08: * All actions may implement this interface, which exposes
09: * the execute() method. However, as of XWork 1.1, this is
10: * not required and is only here to assist users. You are
11: * free to create POJOs that honor the same contract
12: * defined by this interface without actually implementing
13: * the interface.
14: */
15: public interface Action {
16: /**
17: * The action execution was successful. Show result
18: * view to the end user.
19: */
20: public static final String SUCCESS = "success";
21:
22: /**
23: * The action execution was successful but do not
24: * show a view. This is useful for actions that are
25: * handling the view in another fashion like redirect.
26: */
27: public static final String NONE = "none";
28:
29: /**
30: * The action execution was a failure.
31: * Show an error view, possibly asking the
32: * user to retry entering data.
33: */
34: public static final String ERROR = "error";
35:
36: /**
37: * The action execution require more input
38: * in order to succeed.
39: * This result is typically used if a form
40: * handling action has been executed so as
41: * to provide defaults for a form. The
42: * form associated with the handler should be
43: * shown to the end user.
44: * <p/>
45: * This result is also used if the given input
46: * params are invalid, meaning the user
47: * should try providing input again.
48: */
49: public static final String INPUT = "input";
50:
51: /**
52: * The action could not execute, since the
53: * user most was not logged in. The login view
54: * should be shown.
55: */
56: public static final String LOGIN = "login";
57:
58: /**
59: * Where the logic of the action is executed.
60: *
61: * @return a string representing the logical result of the execution.
62: * See constants in this interface for a list of standard result values.
63: * @throws Exception thrown if a system level exception occurs.
64: * Application level exceptions should be handled by returning
65: * an error value, such as Action.ERROR.
66: */
67: public String execute() throws Exception;
68: }
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