It is a simple blueprint application that shows and updates the content of a single Derby database.
Download the sample application here: To install it, simply copy the WAR file in Tomcat's webapps folder. You can then access it via this URL: http://localhost:8080/dbtest/.
Thread Pooling Design
Session Handle State
TOMCAT_HOME/work or else, the existing one is reused.
TOMCAT_HOME/work.
<Context antiJARLocking="true">
<Resource name="jdbc/myDB" auth="Container" type="com.atomikos.jdbc.SimpleDataSourceBean"
factory="org.apache.naming.factory.BeanFactory"
uniqueResourceName="jdbc/myDB"
xaDataSourceClassName="org.apache.derby.jdbc.EmbeddedXADataSource"
exclusiveConnectionMode="true"
connectionPoolSize="3"
connectionTimeout="10"
xaDataSourceProperties="databaseName=../work/users1;createDatabase=create"/>
<Transaction factory="com.atomikos.icatch.jta.UserTransactionFactory" />
</Context>
<?xml version="1.0" encoding="ISO-8859-1"?>
<!DOCTYPE web-app PUBLIC
"-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
"http://java.sun.com/dtd/web-app_2_3.dtd">
<web-app>
<listener>
<listener-class>foo.ContextListener</listener-class>
</listener>
<resource-env-ref>
<resource-env-ref-name>jdbc/myDB</resource-env-ref-name>
<resource-env-ref-type>javax.sql.DataSource</resource-env-ref-type>
</resource-env-ref>
<welcome-file-list>
<welcome-file>test.jsp</welcome-file>
</welcome-file-list>
</web-app>
com.atomikos.icatch.service=com.atomikos.icatch.standalone.UserTransactionServiceFactory com.atomikos.icatch.log_base_dir=../work com.atomikos.icatch.output_dir=../work com.atomikos.icatch.console_log_level=DEBUG
<html>
<head>
<title>DB Test</title>
</head>
<body>
<%
String completion = request.getParameter("completion");
foo.DBTest test = new foo.DBTest();
test.init(completion);
%>
<h2>Transaction completion</h2>
Transaction completion is :<strong><%= completion %></strong>
<h2>Results</h2>
Int stored in JDBC : <strong><%= test.getFoo() %></strong><br />
<hr />
<form action="test.jsp" method="get">
<input type="radio" name="completion" value="commit" checked="true"> Commit<BR>
<input type="radio" name="completion" value="rollback">Rollback<BR>
<button type="submit">Completion</button>
</form>
</body>
</html>
package foo;
import javax.servlet.ServletContextListener;
import javax.servlet.ServletContextEvent;
import com.atomikos.icatch.jta.UserTransactionManager;
public class ContextListener implements ServletContextListener {
private UserTransactionManager utm;
public void contextInitialized(ServletContextEvent event) {
try {
utm = new UserTransactionManager();
utm.init();
System.out.println("initialized transaction manager");
}
catch (Exception ex) {
utm = null;
throw new RuntimeException("cannot initialize UserTransactionManager", ex);
}
}
public void contextDestroyed(ServletContextEvent event) {
if (utm != null) {
utm.close();
System.out.println("shut down transaction manager");
}
}
}
package foo;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.Statement;
import java.sql.SQLException;
import java.sql.Connection;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.sql.DataSource;
import javax.transaction.UserTransaction;
public class DBTest{
int foo = -1;
// value stored in DB
public void init(String completion) {
try{
Context ctx = new InitialContext();
// JDBC stuff
DataSource ds =
(DataSource)ctx.lookup("java:comp/env/jdbc/myDB");
ensureTableExists(ds);
UserTransaction ut = (UserTransaction)ctx.lookup("java:comp/UserTransaction");
Connection conn = ds.getConnection();
System.out.println("<<< beginning the transaction >>>");
ut.begin();
// JDBC statements
Statement stmt = conn.createStatement();
ResultSet rst =
stmt.executeQuery("select id, foo from testdata");
if(rst.next()) {
foo=rst.getInt(2);
}
System.out.println("foo = "+ foo +" (before completion)");
PreparedStatement pstmt = conn.prepareStatement("update testdata set foo=? where id=1");
pstmt.setInt(1,++foo);
pstmt.executeUpdate();
if (completion != null && completion.equals("commit")) {
System.out.println("<<< committing the transaction >>>");
ut.commit();
} else {
System.out.println("<<< rolling back the transaction >>>");
ut.rollback();
}
// we set foo to the value stored in the DB
rst =
stmt.executeQuery("select id, foo from testdata");
if(rst.next()) {
foo=rst.getInt(2);
}
System.out.println("foo = "+ foo +" (after completion)");
conn.close();
System.out.println("<<< done >>>");
}catch(Exception e) {
System.out.print("DBTest >> ");
e.printStackTrace();
}
}
public String getFoo() { return ""+foo; }
private void ensureTableExists(DataSource ds) throws Exception {
Connection c = ds.getConnection();
try {
Statement stmt = c.createStatement();
stmt.executeUpdate("create table testdata (id integer not null primary key, foo integer)");
stmt.executeUpdate("insert into testdata values(1, 1)");
stmt.close();
c.commit();
System.out.println("<<< created table >>>");
}
catch (SQLException ex) {
// ignore
}
c.close();
}
}
| JAR name | Source |
|---|---|
| derby-10.2.2.0.jar | Derby 10.2.2.0 |
| jta.jar | TransactionsEssentials 3.1.5 |
| atomikos-util.jar | TransactionsEssentials 3.1.5 |
| transactions-api.jar | TransactionsEssentials 3.1.5 |
| transactions-jta.jar | TransactionsEssentials 3.1.5 |
| transactions.jar | TransactionsEssentials 3.1.5 |
