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1
2 import java.sql.Connection  ;
3 import java.sql.PreparedStatement ;
4 import java.sql.ResultSet ;
5
6 import javax.naming.Context ;
7 import javax.naming.InitialContext ;
8 import javax.transaction.UserTransaction ;
9
10 public class StandardXAPoolDataSourceExample {
11
12 private static final String USAGE = "usage: java StandardXAPoolDataSourceExample [commit|rollback] [number]";
13 private static final String SQL_REQUEST = "select id, foo from testdata";
14 private static final String SQL_QUERY = "update testdata set foo = ? where id=1";
15 private static final String USER_TRANSACTION_JNDI_NAME = "UserTransaction";
16 private static Connection conn = null;
17
18 private static void printTable() {
19 try {
20 PreparedStatement pstmt = conn.prepareStatement(SQL_REQUEST);
21 ResultSet rset = pstmt.executeQuery();
22 int numcols = rset.getMetaData().getColumnCount();
23 for (int i = 1; i <= numcols; i++) {
24 System.out.print("\t" + rset.getMetaData().getColumnName(i));
25 }
26 System.out.println();
27 while (rset.next()) {
28 for (int i = 1; i <= numcols; i++) {
29 System.out.print("\t" + rset.getString(i));
30 }
31 System.out.println("");
32 }
33 } catch (Exception e) {
34 e.printStackTrace();
35 }
36 }
37
38 private static void updateTable(int newValue) {
39 try {
40 PreparedStatement pstmt = conn.prepareStatement(SQL_QUERY);
41 pstmt.setInt(1, newValue);
42 pstmt.executeUpdate();
43 } catch (Exception e) {
44 e.printStackTrace();
45 }
46 }
47
48 public static void main(String [] args) {
49
50 if (args.length != 2|| (!args[0].equals("commit") && !args[0].equals("rollback"))) {
51 System.err.println(USAGE + "\n");
52 System.exit(1);
53 }
54
55 String completion = args[0];
56
57 int newValue = 0;
58 try {
59 newValue = Integer.parseInt(args[1]);
60 } catch (NumberFormatException e) {
61 System.err.println(USAGE);
62 System.err.println("[number] has to be an integer\n");
63 System.exit(1);
64 }
65
66 System.out.println("start server");
67 DatabaseHelper dbHelper = new DatabaseHelper();
68
69 UserTransaction utx = null;
70 try {
71 System.out.println("create initial context");
72 Context ictx = new InitialContext ();
73 System.out.println("lookup UserTransaction at : " + USER_TRANSACTION_JNDI_NAME);
74 utx = (UserTransaction ) ictx.lookup(USER_TRANSACTION_JNDI_NAME);
75 } catch (Exception e) {
76 System.err.println("Exception of type :" + e.getClass().getName() + " has been thrown");
77 System.err.println("Exception message :" + e.getMessage());
78 e.printStackTrace();
79 System.exit(1);
80 }
81
82 try {
83 System.out.println("get a connection");
84 conn = dbHelper.getConnection();
85 } catch (Exception e) {
86 e.printStackTrace();
87 }
88
89 System.out.println("before transaction, table is:");
90 printTable();
91
92 try {
93 System.out.println("begin a transaction");
94 utx.begin();
95
96 System.out.println("update the table");
97 updateTable(newValue);
98
99 if (completion.equals("commit")) {
100 System.out.println("*commit* the transaction");
101 utx.commit();
102 } else {
103 System.out.println("*rollback* the transaction");
104 utx.rollback();
105 }
106 } catch (Exception e) {
107 System.out.println("Exception of type :" + e.getClass().getName() + " has been thrown");
108 System.out.println("Exception message :" + e.getMessage());
109 e.printStackTrace();
110 System.exit(1);
111 }
112
113 utx = null;
114
115 System.out.println("after transaction, table is:");
116 printTable();
117
118 try {
119 System.out.println("close connection");
120 conn.close();
121
122 } catch (Exception e) {
123 e.printStackTrace();
124 } finally {
125 conn = null;
126 }
127
128 System.out.println("stop server");
129 dbHelper.stop();
130
131 System.out.println("JDBC example is ok.\n");
132 System.exit(0);
133 }
134 }
135 |
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