propagation

The Spring docs do a fantastic job of describing transactional propagation properties. However, I was wondering if there are any well-known, real-world examples available which describe each of these properties more thoroughly in layman's terms? Brad PROPAGATION_REQUIRED class Service { @Transactional(propagation=Propagation.REQUIRED) public void doSomething() { // access a database using a DAO } } When doSomething() is called it will start a new transaction if the caller has not already started a transaction . If the caller of this method has already started a transaction then the callers'

Null propagation is a very nice feature - but where and how does the actual magic happen? Where does frm?.Close() get changed to if(frm != null) frm.Close(); - Does it actually get changed to that kind of code at all? It is done by the compiler. It doesn't change frm?.Close() to if(frm != null) frm.Close(); in terms of re-writing the source code, but it does emit IL bytecode which checks for null. Take the following example: void Main() { Person p = GetPerson(); p?.DoIt(); } Compiles to: IL_0000: ldarg.0 IL_0001: call UserQuery.GetPerson IL_0006: dup IL_0007: brtrue.s IL_000B IL_0009: pop IL

I am a C programmer and just learning some java recently because I am developing one android application. Currently I am in a situation. Following is the one. public Class ClassA{ public ClassA(); public void MyMethod(){ try{ //Some code here which can throw exceptions } catch(ExceptionType1 Excp1){ //Here I want to show one alert Dialog box for the exception occured for the user. //but I am not able to show dialog in this context. So I want to propagate it //to the caller of this method. } catch(ExceptionType2 Excp2){ //Here I want to show one alert Dialog box for the exception occured for

On my page I have a lot of various elements which respond to click events. There are times when I need to block all clicks based on some global flag. Is there a way I can make this check in a centralized location? Right now in each event I check for the flag, for example: var canClick = false; // Global flag // Sample click event: $("#someDiv").click(function(){ if(!canClick) return; // Some stuff ... }); What I'd like to do is have one element which traps all click events before any other elements. I tried doing it on document but these events only occur after the other click events. Example:

I am new to jQuery and I'm trying to understand the concept of capturing and bubbling. I have read a lot of articles, but most of them described event propagation for Javascript. Lets assume we have the following HTML code: <div id="outter"> outter <div id="inner"> inner </div> </div> Capturing is the phase where we go down the DOM elements and bubbling is when we go up. In Javascript you can decide which way to follow (using true or false parameters): element.addEventListener('click',doSomething,true) --> capture phase element.addEventListener('click',doSomething,false) --> bubble phase Is

I can't understand the behavior difference between the PROPAGATION_REQUIRES_NEW and PROPAGATION_NESTED propagation policies. It seems to me that in both cases, the current process is rollbacked but not the whole transaction. Any clue? See this link: PROPAGATION_NESTED versus PROPAGATION_REQUIRES_NEW? Juergen Hoeller explain it very well PROPAGATION_REQUIRES_NEW starts a new, independent "inner" transaction for the given scope. This transaction will be committed or rolled back completely independent from the outer transaction, having its own isolation scope, its own set of locks, etc. The outer