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<a name="ch10"></a>
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<h2 class="first-section-title"><a name="332"></a><a name="ch10lev1sec4"></a>Architect's Exercise: ProjectTrak</h2><p class="first-para">For the ProjectTrak application, which we've been working on in the "Architect's Exercises" throughout this book, we will use CementJ and its <span class="fixed">ValueObject</span> for all value objects. <a class="internaljump" href="#ch10ex10">Listing 10.10</a> has code from the <span class="fixed">ProjectVO</span> class of ProjectTrak. You may recall that we identified this object in <a href="LiB0038.html#184" target="_parent" class="chapterjump">chapter 6</a>.</p>
<div class="example">
<span class="example-title"><span class="example-titlelabel">Listing 10.10: </span>Sample ProjectVO Class from ProjectTrak</span><a name="333"></a><a name="ch10ex10"></a>
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<pre class="literallayout">
1:package com.dvt.app.project.vo;
2:
3:import org.cementj.base.ValueObject;
4:import java.util.Date;
5:import java.io.Serializable;
6:
7:/**
8: * VO representing information about a project. This
9: * class is part of the ProjectTrak application.
10: * <p>Copyright: Delta Vortex Technologies, 2003.
11: */
12:public class ProjectVO
13: extends ValueObject
14: implements Serializable, Comparable
15:{
16:
17: public ProjectVO() {}<a name="334"></a><a name="IDX-135"></a>
18:
19: public String getProjectName()
20: {
21: return _projectName;
22: }
23: public void setProjectName(String name)
24: {
25: if (name == null)
26: {
27: throw new IllegalArgumentException
28: ("Null project name not allowed.");
29: }
30: if (name.equals(""))
31: {
32: throw new IllegalArgumentException
33: ("Blank project name not allowed.");
34: }
35: _projectName = name;
36: }
37:
38: public String[] getProjectBaselineNames()
39: {
40: return _projectBaselines;
41: }
42: public void setProjectBaselineNames(String[] name)
43: {
44: _projectBaselines = name;
45: }
46:
47: public Date getDateCreated()
48: {
49: return _dateCreated;
50: }
51: public void setDateCreated(Date dateCreated)
52: {
53: if (dateCreated == null)
54: {
55: throw new IllegalArgumentException
56: ("Null dateCreated not allowed.");
57: }
58: _dateCreated = dateCreated;
59: }
60:
61: public Date getDateModified()
62: {
63: return _dateLastModified;
64: }
65: public void setDateModified(Date dateLastModified)
66: {<a name="335"></a><a name="IDX-136"></a>
67: if (dateLastModified == null)
68: {
69: throw new IllegalArgumentException
70: ("Null dateLastModified not allowed.");
71: }
72: _dateLastModified = dateLastModified;
73: }
74:
75: public Date getProjectStart()
76: {
77: return _projectStart;
78: }
79: public void setProjectStart(Date start)
80: {
81: _projectStart = start;
82: }
83:
84: public Date getProjectEnd()
85: {
86: return _projectEnd;
87: }
88: public void setProjectEnd(Date end)
89: {
90: _projectEnd = end;
91: }
92:
93: public ResourceVO[] getAssignedResources()
94: {
95: return _assignedResources;
96: }
97: public void setAssignedResources(
98: ResourceVO[] assignedResources)
99: {
100: if (assignedResources == null)
101: {
102: throw new IllegalArgumentException
103: ("Null assignedResources not allowed.");
104: }
105: _assignedResources = assignedResources;
106: }
107:
108: public ProjectTaskVO[] getProjectTasks()
109: {
110: return _projectTasks;
111: }
112: public void setProjectTasks(
113: ProjectTaskVO[] projectTasks)
114: {
115: if (projectTasks == null)<a name="336"></a><a name="IDX-137"></a>
116: {
117: throw new IllegalArgumentException
118: ("Null projectTasks not allowed.");
119: }
120: _projectTasks = projectTasks;
121: }
122:
123: public int compareTo(Object obj)
124: {
125: int comparator = 0;
126: if (obj == null)
127: {
128: throw new IllegalArgumentException
129: ("Null object not allowed.");
130: }
131: if (! (obj instanceof ProjectVO))
132: {
133: throw new IllegalArgumentException
134: ( "Invalid Object Type: " +
135: obj.getClass().getName());
136: }
137:
138: ProjectVO pvo = (ProjectVO) obj;
139: comparator = _projectName.compareTo(
140: pvo._projectName);
141: if (comparator == 0)
142: {
143: comparator = _dateLastModified.compareTo(
144: pvo._dateLastModified);
145: }
146:
147: return comparator;
148: }
149:
150: private String _projectName = null;
151: private String[] _projectBaselines = null;
152: private Date _dateCreated = null;
153: private Date _dateLastModified = null;
154: private ResourceVO[] _assignedResources = null;
155: private ProjectTaskVO[] _projectTasks = null;
156: private Date _projectStart = null;
157: private Date _projectEnd = null;
158:
159:}
</pre>
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<p class="last-para">
<i class="emphasis">Source</i>: /src/com/dvt/app/project/vo/ProjectVO.java</p>
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<p class="para">In addition to implementing all the coding recommendations presented in this chapter, I suggest you check the arguments to mutators to catch illegal variable assignments early. This practice reduces the likelihood that you'll get a derivative <span class="fixed">NullPointerException</span> of something else that's relatively time consuming to debug.</p>
<a name="337"></a><a name="IDX-138"></a>
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