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/Users/lyon/j4p/src/net/server/servlets/HtmlPage.java
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1 package net.server.servlets;
2
3 /**
4 * The HtmlPage class encapsulates the functionality
5 * required to prepare an HTML script to display in
6 * a browser. This class provides methods to construct
7 * various HTML elements such as forms, list boxes,
8 * anchor tags and headlines.
9 *
10 * @author Robert Lysik
11 * @version 1.00
12 */
13 public class HtmlPage {
14 private String strTitle;
15 private String strBody;
16
17 /**
18 * This is the default constructor for the HtmlPage class.
19 * An empty title tag is provided for the title string, as
20 * well as the opening tag for the body section of the
21 * HTML page.
22 */
23 public HtmlPage() {
24 strTitle = new String("<head><title></title></head>");
25 strBody = new String("<body>");
26 }
27
28 /**
29 * This constructor takes a String as an argument which
30 * is used to initialize the title of the page.
31 *
32 * @param String the title of the page
33 */
34 public HtmlPage(String title) {
35 strTitle = new String("<head><title>"
36 + title
37 + "</title></head>");
38
39 strBody = new String("<body>");
40 }
41
42 /**
43 * This function inserts a line break into the HTML
44 * script.
45 */
46 public void addBreak() {
47 strBody += "<br>\r\n";
48 }
49
50 /**
51 * This function inserts a headline tag with the
52 * value provided as a parameter to the function,
53 * as well as the text to be displayed.
54 *
55 * @param int the headline type
56 * @param String the headline text
57 */
58 public void addHeadline(int headlineType,
59 String headlineText) {
60 strBody += "<h" + headlineType + ">";
61 strBody += headlineText;
62 strBody += "</h" + headlineType + ">\r\n";
63 }
64
65 /**
66 * This function inserts a hidden input control
67 * tag into the HTML script.
68 *
69 * @param String name of hidden tag
70 * @param String value of hidden tag
71 */
72 public void addHidden(String name,
73 String value) {
74 strBody += "<input type = " +
75 quote("hidden") +
76 " name = " +
77 quote(name) +
78 " value = " +
79 quote(value) +
80 ">\r\n";
81 }
82
83 /**
84 * This function creates an input element for a form. Input
85 * elements, such as text boxes, radio buttons, and checkboxes
86 * allow the user of an HTML page to enter information which
87 * may then be processed by another page, or by script within
88 * the existing page. These elements must be enclosed within
89 * form tags in order for correct processing.
90 *
91 * @param String the type of form input, i.e. text, radio, checkbox
92 * @param String the name of the input element
93 * @param String the value associated with this element
94 * @param String the size of the element
95 */
96 public void addInput(String type,
97 String name,
98 String value,
99 String size) {
100 strBody += "<input type = " +
101 quote(type) +
102 " name = " +
103 quote(name) +
104 " value = " +
105 quote(value) +
106 " size = " +
107 quote(size) +
108 ">\r\n";
109 }
110
111 /**
112 * This function adds submit button to a form in an HTML page.
113 *
114 * @param String the text to be displayed on the submit button
115 */
116 public void addSubmit(String value) {
117 strBody += "<input type = " +
118 quote("submit") +
119 " value = " +
120 quote(value) +
121 ">\r\n";
122 }
123
124 /**
125 * This function adds a normal text string to the
126 * HTML script.
127 *
128 * @param String the text to be displayed
129 */
130 public void addText(String text) {
131 strBody += text + "\r\n";
132 }
133
134 /**
135 * This function adds a closing form HTML tag.
136 */
137 public void endForm() {
138 strBody += "</form>\r\n";
139 }
140
141 /**
142 * This function returns the HTML script to generate the
143 * page as it is currently defined. The title and body
144 * elements of the HTML page are enclosed in opening and closing
145 * HTML tags.
146 */
147 public String getHtml() {
148 String html = new String();
149
150 html = "<html>"
151 + strTitle
152 + strBody
153 + "</body>"
154 + "</html>";
155
156 return html;
157 }
158
159 /**
160 * This function creates an input element which is called a
161 * select list. This is a drop down list box, if the size
162 * of the list box is set to one, or a normal list box if
163 * the size is greater than one. This element must be
164 * encapsulated within the FORM section of an HTML page in
165 * order for correct processing to occur.
166 *
167 * @param String the name of the select list
168 * @param String the size of the select list. If set to
169 * one, this becomes a drop down list box.
170 * @param String the values associated with the list box
171 * @param String the text displayed in the list box.
172 */
173 public String getSelect(String name,
174 String size,
175 String values[],
176 String text[]) {
177 String select = new String();
178
179 // The opening tag for the select list includes
180 // the name of the list and its size.
181 select += "<select name = " +
182 quote(name) +
183 " size = " +
184 quote(size) +
185 ">\r\n";
186
187 // Each element of the list box is then added, prefixed
188 // by the OPTION tag.
189 for (int index = 0; index < values.length; index++) {
190 select += "<option value = " +
191 quote(values[index]) +
192 ">" +
193 text[index] +
194 "\r\n";
195 }
196
197 // The closing tag for the select list is then added
198 select += "</select>\r\n";
199
200 return select;
201 }
202
203 /**
204 * This function returns a string which is surrounded
205 * by quotes.
206 *
207 * @param String the string to be encapsulated in quotes
208 */
209 public String quote(String s) {
210 return '\"' + s + '\"';
211 }
212
213 /**
214 * This function inserts the opening tag for a form into
215 * the HTML script.
216 *
217 * @param String the method of form submission, either
218 * post or get.
219 * @param String the action attribute of the form.
220 */
221 public void startForm(String method, String action) {
222 strBody += "<form method = " +
223 quote(method) +
224 " action = " +
225 quote(action) +
226 ">\r\n";
227 }
228 }
229