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1
24
25 package edu.rice.rubbos.servlets;
26
27 import java.io.IOException  ;
28 import java.net.URLEncoder ;
29 import java.sql.Connection ;
30 import java.sql.PreparedStatement ;
31 import java.sql.ResultSet ;
32
33 import javax.servlet.ServletException ;
34 import javax.servlet.http.HttpServletRequest ;
35 import javax.servlet.http.HttpServletResponse ;
36
37 public class BrowseCategories extends RubbosHttpServlet
38 {
39
40 public int getPoolSize()
41 {
42 return Config.BrowseCategoriesPoolSize;
43 }
44
45 private void closeConnection(PreparedStatement stmt, Connection conn)
46 {
47 try
48 {
49 if (stmt != null)
50 stmt.close(); }
52 catch (Exception ignore)
53 {
54 }
55
56 try
57 {
58 if (conn != null)
59 releaseConnection(conn);
60 }
61 catch (Exception ignore)
62 {
63 }
64
65 }
66
67
68 public void doGet(HttpServletRequest request, HttpServletResponse response)
69 throws IOException , ServletException
70 {
71
72 ServletPrinter sp = null;
73 PreparedStatement stmt = null;
74 Connection conn = null;
75
76 sp = new ServletPrinter(response, "BrowseCategories");
77 sp.printHTMLheader("RUBBoS available categories");
78
79 conn = getConnection();
80
81 ResultSet rs = null;
82 try
83 {
84 stmt = conn.prepareStatement("SELECT * FROM categories");
85 rs = stmt.executeQuery();
86 }
87 catch (Exception e)
88 {
89 sp.printHTML("Failed to execute Query for BrowseCategories: " + e);
90 closeConnection(stmt, conn);
91 return;
92 }
93 try
94 {
95 if (!rs.first())
96 {
97 sp
98 .printHTML("<h2>Sorry, but there is no category available at this time. Database table is empty</h2><br>\n");
99 closeConnection(stmt, conn);
100 return;
101 }
102 else
103 sp.printHTML("<h2>Currently available categories</h2><br>\n");
104
105 int categoryId;
106 String categoryName;
107
108 do
109 {
110 categoryId = rs.getInt("id");
111 categoryName = rs.getString("name");
112 sp
113 .printHTMLHighlighted("<a HREF=\"/rubbos/servlet/edu.rice.rubbos.servlets.BrowseStoriesByCategory?category="
114 + categoryId
115 + "&categoryName="
116 + URLEncoder.encode(categoryName)
117 + "\">"
118 + categoryName
119 + "</a><br>\n");
120 }
121 while (rs.next());
122 }
123 catch (Exception e)
124 {
125 sp.printHTML("Exception getting categories: " + e + "<br>");
126 }
127
128 closeConnection(stmt, conn);
129
130
131 sp.printHTMLfooter();
132
133 }
134
135 public void doPost(HttpServletRequest request, HttpServletResponse response)
136 throws IOException , ServletException
137 {
138 doGet(request, response);
139 }
140
141 }
142 |
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