Spring's Webutils class source parsing

Reference article: 1. http://www.ibm.com/developerworks/cn/java/j-lo-spring-utils1/

2.spring Source Code
Webutils
The webutils in the Org.springframework.web.util package is a very useful tool class that provides an easy-to-use proxy approach to many servlet APIs, reducing the complexity of accessing the Servlet API, which can be seen as a common Ser Vlet the façade class of the API method.
The following methods facilitate access to objects and properties in HttpServletRequest and HttpSession:

(1) Getsessionattribute

Gets the object that HttpSession a specific property name, otherwise you must do the same with Request.getSession.getAttribute (name);

Java code

2. /**
4. * Check The given request for a session attribute of the given name.
6. * Returns NULL if there is no session or if the session has no such attribute.
8. * Does not create a new session if none have existed before!
10. * @param request current HTTP request
12. * @param name The name of the session attribute
14. * @return The value of the session attribute, or <code>null</code> if not found
16.  */   
18. Public static Object Getsessionattribute (httpservletrequest request, String name) {
20. Assert.notnull (Request, "Request must not is null");
22. HttpSession session = Request.getsession (false);
24. return  (Session! = null ? Session.getattribute (name): null);
26. }

(2) Getrequiredsessionattribute

Similar to the previous method, except that it is mandatory to have the specified attribute in the HttpSession, otherwise throws an exception;

Java code

2. /**
4. * Check The given request for a session attribute of the given name.
6. * Throws An exception if there are no session or if the session has no such
8. * attribute. Does not create a new session if none have existed before!
10. * @param request current HTTP request
12. * @param name The name of the session attribute
14. * @return The value of the session attribute, or <code>null</code> if not found
16. * @throws IllegalStateException If the session attribute could not be found
18.  */   
20. Public static Object Getrequiredsessionattribute (httpservletrequest request, String name)
22. throws IllegalStateException {
26. Object attr = getsessionattribute (request, name);
28. if (attr = = null) {
30. Throw New illegalstateexception ("No session attribute " + name + "' Found"  /c7>);
32. }
34. return  attr;
36. }

(3) Setsessionattribute

Sets the value for the specified attribute in the session, and removes the attribute from the session if the passed value is null

Java code

2. /**
4. * Set The session attribute with the given name to the given value.
6. * Removes the session attribute if value is null, if a session existed at all.
8. * Does not create a new session if not necessary!
10. * @param request current HTTP request
12. * @param name The name of the session attribute
14. * @param value The value of the session attribute
16.  */   
18. Public  static void Setsessionattribute (httpservletrequest request, String name, Object value) {
20. Assert.notnull (Request, "Request must not is null");
22. if (value = null) {
24. Request.getsession (). SetAttribute (name, value);
26. }
28. Else  {  
30. HttpSession session = Request.getsession (false);
32. if (session = null) {
34. Session.removeattribute (name);
36. }
38. }
40. }

(4) Exposerequestattributes

The MAP element is added to the ServletRequest attribute list, and when the request is directed (forward) to the next handler, the request properties can be accessed;

Java code

2. /**
4. * Expose The given MAP as request attributes, using the keys as attribute names
6. * and the values as corresponding attribute values. Keys need to be Strings.
8. * @param request current HTTP request
10. * @param attributes the attributes Map
12.  */   
14. Public static void exposerequestattributes (servletrequest request, map< String,?> attributes) {
16. Assert.notnull (Request, "Request must not is null");
18. Assert.notnull (attributes, "attributes Map must not being null");
20. for (map.entry<string,?> entry:attributes.entrySet ()) {
22. Request.setattribute (Entry.getkey (), Entry.getvalue ());
24. }
26. }

(5) GetCookie

Gets the Cookie object for a specific name in the HttpServletRequest. If you need to create a Cookie, Spring also provides a handy cookiegenerator tool class;

Java code

2. /**
4. * Retrieve The first cookie with the given name. Note that multiple
6. * Cookies can have the same name but different paths or domains.
8. * @param request current servlet request
10. * @param name Cookie name
12. * @return The first cookie with the given name, or <code>null</code> if none is found
14.  */   
16. Public static Cookie GetCookie (httpservletrequest request, String name) {
18. Assert.notnull (Request, "Request must not is null");
20. Cookie cookies[] = request.getcookies ();
22. if (cookie = null) {
24. for (Cookie cookie:cookies) {
26. if (Name.equals (Cookie.getname ())) {
28. return  cookies;
30. }
32. }
34. }
36. return   null;
38. }

(6) Extractfilenamefromurlpath

To intercept a file name from a URL address

Java code

2. /**
4. * Extract the URL filename from the given request URL path.
6. * correctly resolves nested paths such as "/products/view.html" as well.
8. * @param urlpath the request URL path (e.g. "/index.html")
10. * @return The extracted URI filename (e.g. "index")
12.  */   
14. Public static string Extractfilenamefromurlpath (String urlpath) {
16. String filename = Extractfullfilenamefromurlpath (URLPath);
18. int Dotindex = filename.lastindexof ('. ' )  );
20. if (Dotindex! =-1) {
22. filename = filename.substring (0, dotindex);
24. }
26. return  filename;
28. }
32. /**
34. * Extract the full URL, filename (including file extension) from the given request URL path.
36. * correctly resolves nested paths such as "/products/view.html" as well.
38. * @param urlpath the request URL path (e.g. "/products/index.html")
40. * @return The extracted URI filename (e.g. "index.html")
42.  */   
44. Public static string Extractfullfilenamefromurlpath (String urlpath) {
46. int end = Urlpath.indexof ('; ')  );
48. if (end = =-1) {
50. End = Urlpath.indexof ('? ' )  );
52. if (end = =-1) {
54. End = Urlpath.length ();
56. }
58. }
60. int begin = Urlpath.lastindexof ('/', end) + 1  ;
62. return  urlpath.substring (begin, end);
64. }
    

Spring's Webutils class source parsing