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This article is about how to use JSP and JDBC. The editor thinks it is very practical, so share it with you as a reference and follow the editor to have a look.

1.

Equivalent to

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Anni.ContactDao is a bean that encapsulates database operations.

Equivalent to

In the above code, just to create an instance of an object, why not use new? it's much less code than this, and it's easier to understand. Why do we insist on using jsp:useBean?

Notice the scope= "application" in the tag. Application is one of the four scopes we have introduced.

We first get the object corresponding to contactDao from application, and then determine whether the result is null. If it means that this variable has not been initialized for null, we need to use new to create an object instance and put it into application. * * what we get is this contactDao instance.

3. Create.jsp contains information about form submission

Save.jsp form submission information processing

Contact is the get,set method with the corresponding attribute in the corresponding entity bean name

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First take the contactDao from the application, and then create a contact. No scope was specified when the contact was created. By default, this local variable is only created using new, which does not affect any scope. Jsp:setProperty is something new, and its purpose is to set data for a javabean. We have previously created a contact instance using jsp:useBean, and now we set the data for this instance through name= "contact". Property can specify a property, such as property= "username", or use an asterisk (*) to batch set all the properties that can be found. This jsp action is actually equivalent to the following code.

Contact.setUsername (request.getParameter ("username")); contact.setSex (request.getParameter ("sex")); contact.setEmail (request.getParameter ("email")); contact.setQq (request.getParameter ("qq")); contact.setDescn (request.getParameter ("descn")); contactDao.save (contact); response.sendRedirect ("list.jsp"); Thank you for reading! This is the end of the article on "how to use JSP and JDBC". I hope the above content can be of some help to you, so that you can learn more knowledge. if you think the article is good, you can share it for more people to see!

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