Spring MVC dispatcherservlet Details of the pick-and-recall tool class Utils

Static initialization of Dispatcherservlet

    /*** Name of the class path resource (relative to the Dispatcherservlet class) * that defines Dispatcherservlet '     s default strategy names. */    Private Static FinalString Default_strategies_path = "Dispatcherservlet.properties";Private Static FinalProperties defaultstrategies; Static {        //Load Default strategy implementations from properties file. //This is currently strictly internal and not meant to be customized//By application developers.        Try{Classpathresource Resource=NewClasspathresource (Default_strategies_path, Dispatcherservlet.class); Defaultstrategies= propertiesloaderutils. LoadProperties (Resource); }        Catch(IOException ex) {Throw NewIllegalStateException ("Could not load ' dispatcherservlet.properties ':" +ex.getmessage ()); }    }

Configuration file Loading

    /*** Load properties from the given resource (in Iso-8859-1 encoding). * @paramresource the resource to load from *@returnThe populated Properties instance *@throwsIOException If loading failed *@see#fillProperties (java.util.Properties, Resource)*/     Public StaticProperties loadProperties (Resource Resource)throwsIOException {Properties props=NewProperties ();        Fillproperties (props, Resource); returnprops; }

Property padding:

    /*** Fill The given properties from the given resource (in Iso-8859-1 encoding). * @paramprops The Properties instance to fill *@paramresource the resource to load from *@throwsIOException If loading failed*/     Public Static voidFillproperties (Properties props, Resource Resource)throwsIOException {InputStream is=Resource.getinputstream (); Try{String filename=Resource.getfilename (); if(FileName! =NULL&&Filename.endswith (xml_file_extension))            {Props.loadfromxml (IS); }            Else{props.load (IS); }        }        finally{is.close (); }    }

What can we get from this?

We can take it directly. As a tool class for reading property files.

Dispatcherservlet's policy initialization

Initialize the policy code:

    /**      * Initialize The strategy objects that this servlet uses.     * <p>may is overridden in subclasses in order to initialize further strategy objects.      */    protected void initstrategies (ApplicationContext context) {        initmultipartresolver (context);        Initlocaleresolver (context);        Initthemeresolver (context);        Inithandlermappings (context);        Inithandleradapters (context);        Inithandlerexceptionresolvers (context);        Initrequesttoviewnametranslator (context);        Initviewresolvers (context);        Initflashmapmanager (context);    }

Let's look at one more of this method structure diagram:

From the diagram above we can see that they all work together in one way:

/*** Create A List of default strategy objects for the given strategy interface. * <p>the default implementation uses the "Dispatcherservlet.properties" file (in the same * package as the DISPA Tcherservlet Class) to determine the class names.     It instantiates * The strategy objects through the context ' s beanfactory. * @paramcontext the current Webapplicationcontext *@paramstrategyinterface The Strategy interface *@returnThe List of corresponding strategy objects*/@SuppressWarnings ("Unchecked")    protected<T> list<t> getdefaultstrategies (applicationcontext context, class<t>strategyinterface) {String key=Strategyinterface.getname (); String value=Defaultstrategies.getproperty (key); if(Value! =NULL) {string[] classnames= stringutils. Commadelimitedlisttostringarray (value); List<T> strategies =NewArraylist<t>(classnames.length);  for(String classname:classnames) {Try{Class<?> Clazz =classutils. forname (ClassName, Dispatcherservlet.class. getClassLoader ()); Object Strategy=createdefaultstrategy (context, clazz);                Strategies.add ((T) strategy); }                Catch(ClassNotFoundException ex) {Throw NewBeaninitializationexception ("Could not find Dispatcherservlet ' s default Strategy class [" + ClassName + "] for inte Rface ["+ Key +"] ", ex); }                Catch(Linkageerror err) {Throw NewBeaninitializationexception ("Error loading Dispatcherservlet ' s default Strategy class [" + ClassName + "] for Inter Face ["+ key +"]: Problem with class file or dependent class ", err); }            }            returnstrategies; }        Else {            return NewLinkedlist<t>(); }    }

StringUtils and Classutils can be a rich code base OH.

Further, we can find all the *utils.java classes from the Spring repository, discover a huge code base, learn from and re-use this kind of tool library, we can improve our code base and speed up the development efficiency.

Spring MVC dispatcherservlet detailed utils tool class