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/Users/lyon/j4p/src/net/server/servlets/PhoneBook.java
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1 package net.server.servlets;
2
3 import javax.servlet.ServletConfig;
4 import javax.servlet.ServletException;
5 import javax.servlet.http.HttpServlet;
6 import javax.servlet.http.HttpServletRequest;
7 import javax.servlet.http.HttpServletResponse;
8 import javax.servlet.http.HttpUtils;
9 import java.io.IOException;
10 import java.io.PrintWriter;
11 import java.sql.*;
12 import java.util.Hashtable;
13
14 /*
15 PhoneBook.java:
16 Example of a middle-tier Java application - a servlet
17 accessing a back-end database.
18
19 Copyright (c) 1999 Nathan Meyers
20 $Id: PhoneBook.java,v 1.6 1999/11/10 03:44:25 nathanm Exp $
21
22 Permission is hereby granted, free of charge, to any person obtaining
23 a copy of this software and associated documentation files (the
24 "Software"), to deal in the Software without restriction, including
25 without limitation the rights to use, copy, modify, merge, publish,
26 distribute, sublicense, and/or sell copies of the Software, and to
27 permit persons to whom the Software is furnished to do so, subject
28 to the following conditions:
29
30 The above copyright notice and this permission notice shall be
31 included in all copies or substantial portions of the Software.
32
33 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
34 KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
35 WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
36 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
37 BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
38 AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
39 IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
40 THE SOFTWARE.
41 */
42
43 public class PhoneBook extends HttpServlet {
44 Connection connection = null;
45
46 public void init(ServletConfig config) throws ServletException {
47 // Servlet initialization
48 super.init(config);
49 try {
50 // Load the MySQL JDBC driver
51 Class.forName("org.gjt.mm.mysql.Driver");
52 } catch (ClassNotFoundException e) {
53 throw new ServletException(e.toString());
54 }
55 }
56
57 private void doOutput1(PrintWriter writer) {
58 writer.println(
59 "<HTML>\n" +
60 "<HEAD>\n" +
61 "<TITLE>Phone Book</TITLE>" +
62 "</HEAD>\n" +
63 "<BODY>\n" +
64 "<CENTER>\n" +
65 "<H1>Telephone Book</H1>\n" +
66 "<FORM ACTION=\"PhoneBook\" METHOD=\"POST\">" +
67 "<TABLE>\n" +
68 "<TR>\n" +
69 " <TD>Last Name</TD>\n" +
70 " <TD><INPUT TYPE=\"TEXT\" SIZE=20 NAME=\"LastName\"></TD>" +
71 "</TR><TR>\n" +
72 " <TD>First Name</TD>\n" +
73 " <TD><INPUT TYPE=\"TEXT\" SIZE=20 NAME=\"FirstName\"></TD>" +
74 "</TR><TR>\n" +
75 " <TD>Country Code</TD>\n" +
76 " <TD><INPUT TYPE=\"TEXT\" SIZE=5 NAME=\"CountryCode\"></TD>" +
77 "</TR><TR>\n" +
78 " <TD>Area Code</TD>\n" +
79 " <TD><INPUT TYPE=\"TEXT\" SIZE=5 NAME=\"AreaCode\"></TD>" +
80 "</TR><TR>\n" +
81 " <TD>Phone Number</TD>\n" +
82 " <TD><INPUT TYPE=\"TEXT\" SIZE=15 NAME=\"PhoneNum\"></TD>" +
83 "</TR>\n" +
84 "</TABLE>" +
85 "<INPUT TYPE=\"Submit\" NAME=\"Query\" VALUE=\"Query\">\n" +
86 "<INPUT TYPE=\"Submit\" NAME=\"Add\" VALUE=\"Add New Entry\">\n" +
87 "<INPUT TYPE=\"Reset\" VALUE=\"Reset\">\n" +
88 "</FORM><BR>"
89 );
90 }
91
92 private void doOutput2(PrintWriter writer) {
93 writer.println("</BODY></HTML>");
94 }
95
96 public void doGet(HttpServletRequest req, HttpServletResponse resp) {
97 // Get action puts up the query form.
98 resp.setContentType("text/html");
99 PrintWriter writer = null;
100 try {
101 writer = resp.getWriter();
102 } catch (IOException e) {
103 return;
104 }
105 doOutput1(writer);
106 doOutput2(writer);
107 writer.close();
108 }
109
110 public synchronized void doPost(HttpServletRequest req,
111 HttpServletResponse resp) {
112 // Post action puts up the query form and responds to the post
113 resp.setContentType("text/html");
114 PrintWriter writer = null;
115 try {
116 writer = resp.getWriter();
117 } catch (IOException e) {
118 return;
119 }
120
121 // Output the form
122 doOutput1(writer);
123
124 // Open or reopen the connection if needed
125 try {
126 // Open a connection to the server - no login or password.
127 // The form of the URL (first parameter) is dictated by the
128 // MySQL jdbc driver. Default MySQL TCP port is 3306
129 if (connection == null || connection.isClosed())
130 connection = DriverManager.getConnection(
131 "jdbc:mysql://localhost:3306/test", "lyon", null);
132 } catch (SQLException e) {
133 writer.println("Error: Cannot open database connection\n");
134 doOutput2(writer);
135 writer.close();
136 return;
137 }
138
139 // Open input from the POST data
140 Hashtable postData = null;
141 try {
142 // Build a hashtable of the posted data
143 postData = HttpUtils.parsePostData(
144 req.getContentLength(), req.getInputStream());
145 } catch (IOException e) {
146 writer.println("Error: Cannot read post data\n");
147 }
148 if (postData.containsKey("Add")) {
149 // User requested to add a new entry... make sure
150 // at least last name is non-empty
151 if (((String[]) postData.get("LastName"))[0].length() == 0)
152 writer.println("Error: No last name specified for Add");
153 else
154 try {
155 // Construct and execute an SQL statement to insert
156 Statement stmt = connection.createStatement();
157 stmt.executeUpdate(
158 "INSERT INTO phonelist VALUES (" +
159 "'" +
160 ((String[]) postData.get("LastName"))[0] +
161 "','" +
162 ((String[]) postData.get("FirstName"))[0] +
163 "','" +
164 ((String[]) postData.get("CountryCode"))[0] +
165 "','" +
166 ((String[]) postData.get("AreaCode"))[0] +
167 "','" +
168 ((String[]) postData.get("PhoneNum"))[0] +
169 "');");
170 writer.println("New entry added for " +
171 ((String[]) postData.get("LastName"))[0]);
172 } catch (SQLException e) {
173 writer.println("Error: " + e.toString());
174 } catch (NullPointerException e) {
175 // This will trigger if a form field is missing from
176 // the post.
177 writer.println("Error: " + e.toString());
178 }
179 } else {
180 // User requested a query...
181 ResultSet results = null;
182 try {
183 // Construct an SQL query string. First figure out
184 // the qualifiers based on form input
185 StringBuffer queryQualifiers = new StringBuffer();
186 appendQueryQualifiers(queryQualifiers, "lastname",
187 (postData.get("LastName")));
188 appendQueryQualifiers(queryQualifiers, "firstname",
189 (postData.get("FirstName")));
190 appendQueryQualifiers(queryQualifiers, "countrycode",
191 (postData.get("CountryCode")));
192 appendQueryQualifiers(queryQualifiers, "areacode",
193 (postData.get("AreaCode")));
194 appendQueryQualifiers(queryQualifiers, "number",
195 (postData.get("PhoneNum")));
196
197 Statement stmt = connection.createStatement();
198 results = stmt.executeQuery(
199 "SELECT * FROM phonelist" +
200 queryQualifiers +
201 ";"
202 );
203
204 if (results == null)
205 writer.println("Null result from query");
206 else {
207 // Print headers
208 writer.println(
209 "<TABLE BORDER=\"2\">\n" +
210 "<TR>\n" +
211 " <TD><CENTER><B>Last Name</B></CENTER></TD>\n" +
212 " <TD><CENTER><B>First Name</B></CENTER></TD>\n" +
213 " <TD><CENTER><B>Country Code</B></CENTER></TD>\n" +
214 " <TD><CENTER><B>Area Code</B></CENTER></TD>\n" +
215 " <TD><CENTER><B>Phone Number</B></CENTER></TD>\n" +
216 "</TR>");
217
218 while (results.next()) {
219 writer.println(
220 "<TR>" +
221 " <TD>" + results.getString(1) + "</TD>\n" +
222 " <TD>" + results.getString(2) + "</TD>\n" +
223 " <TD>" + results.getString(3) + "</TD>\n" +
224 " <TD>" + results.getString(4) + "</TD>\n" +
225 " <TD>" + results.getString(5) + "</TD>\n" +
226 "</TR>");
227 }
228 writer.println("</TABLE>");
229 }
230 } catch (SQLException e) {
231 writer.println("Error: " + e.toString());
232 }
233 }
234 doOutput2(writer);
235 writer.close();
236 }
237
238 // appendQueryQualifiers: A utility to assist in constructing
239 // the query string
240 private void appendQueryQualifiers(StringBuffer qualifiers,
241 String dbfield,
242 Object formdata) {
243 if (formdata == null) return;
244 String forminfo = ((String[]) formdata)[0];
245 // Was anything specified for this form field?
246 if (forminfo.length() > 0) {
247 // Yes
248 if (qualifiers.length() == 0)
249 qualifiers.append(" WHERE");
250 else
251 qualifiers.append(" AND");
252 qualifiers.append(" " + dbfield + " = \"" +
253 forminfo + "\"");
254 }
255 }
256
257 public String getServletInfo() {
258 return "PhoneBook";
259 }
260 }
261