c# code 128 barcode generator Adjusting the delay in a polling loop in C#

Access code 128b in C# Adjusting the delay in a polling loop

Mailing list subscribers have shared their experience with the community and told us that it s also safe to set extra response header values B. These headers make sure that the end user always gets the most recent version of the PDF, and not a PDF that is loaded from the cache on the client side. This is important if the content of the PDF changes frequently, which would happen if it reports about real-time data. C solves the problem caused by old browser and PDF viewer configurations. Note that there are several serious downsides to this solution. When you need to generate large files, you risk an OutOfMemoryException on the server side, and a timeout on the client side. You can work around the server-side problem by writing the PDF to a temporary file on the server and asking the end user to fetch the file when it s finished. Don t forget to delete the file once it s served to the browser.

Since the native SQL is tightly coupled to the actual mapped tables and columns, we strongly recommend that you define all native SQL queries in the mapping document instead of embedding them in the Java code. If, in some special cases, you need even more control over the SQL that is executed, or if you want to call a stored procedure using JDBC, Hibernate offers you a way to get a JDBC connection. A call to session.connection() returns the currently active JDBC Connection from the Session. It s not your responsibility to close this connection, just to execute whatever SQL statements you like and then continue using the Session (and finally, close the Session). The same is true for transactions; you must not commit or roll back this connection yourself (unless you completely manage the connection for Hibernate, without a connection pool or container datasource).

dest = CXxxx(source)

To give the page its required behavior, code must be written that runs when each of the link buttons is clicked. The code for the two buttons responsible for switching the display mode of the page is similar to the code we wrote in chapter 4 when we wrote the ModeChanger user control. It simply sets the DisplayMode property of the WebPartManager for the page to the appropriate value:

Listing 4.2 A class for wrapping checked exceptions in runtime exceptions while maintaining the stack trace

To use these commands, you must first create a Tomcat user with administration rights. Do this by adding a user entry in the file CATALINA_HOME/conf/tomcatusers.xml with the role of manager.

/** * Aspect which records all incoming invocations * such that we may perform auditing later * * @author <a href="mailto:andrew.rubinger@jboss.org">ALR</a> * @version $Revision: $ */

Creating controllers like this by hand would be an effort in extreme tedium, and luckily you don t have to do it by hand. This is where IoC tools (also known as IoC containers) come in handy. There are quite a few to choose from, but currently these are the three most popular:

The class also includes four static methods used as helpers to manipulate instances of widget data throughout the application. Three of these methods are related to persistence of SiteMonitorModel data, and a fourth provides date formatting. This date formatting method was included to help standardize and centralize Date string representation. The following listing presents the implementation of the SiteMonitorModel class, minus a few setter/getters, which are omitted here but are included in the full source listing available for download.

private StreamConnectionNotifier createNotifier() throws IOException { return (StreamConnectionNotifier) Connector.open("serversocket://:4444", Create the socket Connector.READ_WRITE, true); connection }

A process scope cache may store the persistent instances themselves in the cache, or it may store just their persistent state in a disassembled format. Every unit of work that accesses the shared cache then reassembles a persistent instance from the cached data. A cluster scope cache requires some kind of remote process communication to maintain consistency. Caching information must be replicated to all nodes in the cluster. For many (not all) applications, cluster scope caching is of dubious value, because reading and updating the cache may be only marginally faster than going straight to the database. Persistence layers may provide multiple levels of caching. For example, a cache miss (a cache lookup for an item that isn t contained in the cache) at the transaction scope may be followed by a lookup at the process scope. A database request is the last resort. The type of cache used by a persistence layer affects the scope of object identity (the relationship between Java object identity and database identity). Caching and object identity Consider a transaction-scoped cache. It seems natural that this cache is also used as the identity scope of objects. This means the cache implements identity handling: Two lookups for objects using the same database identifier return the same actual Java instance. A transaction scope cache is therefore ideal if a persistence mechanism also provides unit of work-scoped object identity. Persistence mechanisms with a process scope cache may choose to implement process-scoped identity. In this case, object identity is equivalent to database identity for the whole process. Two lookups using the same database identifier in two concurrently running units of work result in the same Java instance. Alternatively, objects retrieved from the process scope cache may be returned by value. In this case, each unit of work retrieves its own copy of the state (think about raw data), and resulting persistent instances aren t identical. The scope of the cache and the scope of object identity are no longer the same. A cluster scope cache always needs remote communication, and in the case of POJO-oriented persistence solutions like Hibernate, objects are always passed

Look at the generated SQL: