A locale includes language, formatting of dates, numbers, and currency amounts, etc. However, there is no timezone information provided by the HTTP request header. If no such header presents, it should the default value of your system. The attribute " value " should be either a locale name string, or an instance of the java.
Locale class. The optional attribute " variant " can be used to specify the browser or OS, e. The value for the basename attribute should not include any localization suffixes or filename extensions. You will see??? Let us begin JSTL sql actions with an example. Setting Up Database : Create a database called " ebookshop ", with a table called " books " with 5 columns: id , title , author , price , qty.
Assume that the MySQL is running on port , with a user called " myuser " with password. JSBC's Datasource is a factory for obtaining database connections. DataSource supports so-called connection pooling to reduce the overhead associated with the creating and initializing connections.
Let's try out the connection pooling. Tomcat provides built-in support for datasource with connection pooling, which are made available to applications through the Java Naming and Directory Interface JNDI. The returned result set implements javax. Result interface, with the following properties:.
For example, the following SQL statement contains a parameter denoted as '? Integer instead of a result set. A transaction is a sequence of database operations that must either succeed or fail as a group. JSP 2. A second set of XML-compliant tag with a prefix of " jsp " is defined as follows:. We shall rewrite the " first. Latest version tested: JDK 1. Introduction Instead of static contents that are indifferent, Java Servlet was introduced to generate dynamic web contents that are customized according to users' requests e.
Advantages of JSP Separation of static and dynamic contents : The dynamic contents are generated via programming logic and inserted into the static template. This greatly simplifies the creation and maintenance of web contents. Reuse of components and tag libraries : The dynamic contents can be provided by re-usable components such as JavaBean, Enterprise JavaBean EJB and tag libraries - you do not have to re-inventing the wheels.
Java's power and portability. Check the console message to confirm that hellojsp has been deployed: xxxx, xxxx xx:xx:xx xx org. Start a browser. We shall explain these codes later. Revisit Java Servlets A typical Java servlet as shown below contains three groups of methods: init , destroy , and one or more service methods such as doGet and doPost. HttpJspBase implements org. A JspWriter called out , corresponding to servlet's PrintWriter , is allocated to write the response message over the network to the client.
Scriptlets form the program logic. The Java expression is placed inside a out. In other words, the Java expression will be evaluated, and the result of the evaluation written out as part of the response message. Servlet servlet, javax. ServletRequest request, javax. ServletResponse response, java. The default " action " is the current page i. The JSP scriptlet checks if the query parameter " author " exists. For the first request, " author " parameter is absent. Once the user fills in and submits the form, " author " will be present in the HTTP request.
The values are echoed back to the client in an unordered list. Date ; out. A JSP action may contain sub-action. The syntax is as follows. It does not have public variables. It is defined in a named package. It can not be kept in the default no-name package. For a private variable xxx , there is a public getter getXxx or isXxx for boolean and a public setter setXxx.
It implements Serializable interface, so that its state can be stored and retrieved to and from external storage, for persistent. The attribute scope specifies the scope of this bean: page : default, stored in PageContext , available to this page only.
UserBean called " user ". UserBean to the value of the request parameter " username " i. UserBean i. Keep the " jsp " and " html " files available to the users. Instead of using a map-entries element, it is also possible to assign the entire map using a value element that specifies a map-typed expression.
The list-entries element is used to initialize the values of an array or List property. Each individual value of the array or List is initialized using a value or null-value element. Here is an example:. This example initializes an array or a List.
The type of the corresponding property in the bean determines which data structure is created. The list-entries element defines the list of values in the array or List. The value element specifies a single value in the array or List and can reference a property in another bean.
The null-value element will cause the setBooks method to be called with an argument of null. A null property cannot be specified for a property whose data type is a Java primitive, such as int or boolean.
Sometimes you might want to create a bean that also references other managed beans so that you can construct a graph or a tree of beans. The following managed-bean declarations create a CustomerBean instance that has two AddressBean properties: one representing the mailing address and the other representing the street address. This declaration results in a tree of beans with CustomerBean as its root and the two AddressBean objects as children.
The first CustomerBean declaration with the managed-bean-name of customer creates a CustomerBean in request scope. This bean has two properties, mailingAddress and streetAddress. These properties use the value element to reference a bean named addressBean. The second managed bean declaration defines an AddressBean but does not create it, because its managed-bean-scope element defines a scope of none.
Recall that a scope of none means that the bean is created only when something else references it. Because both the mailingAddress and the streetAddress properties reference addressBean using the value element, two instances of AddressBean are created when CustomerBean is created.
A session-scoped object, for example, cannot point to a request-scoped object. And objects with none scope have no effective life span managed by the framework, so they can point only to other none -scoped objects.
Table outlines all of the allowed connections. Be sure not to allow cyclical references between objects. For example, neither of the AddressBean objects in the preceding example should point back to the CustomerBean object, because CustomerBean already points to the AddressBean objects.
Asked 8 years, 10 months ago. Active 8 years, 10 months ago. Viewed 3k times. JasperException: javax. ServletException: javax. Improve this question. Arjan Tijms Rasoul Taheri Rasoul Taheri 2 2 gold badges 14 14 silver badges 32 32 bronze badges. Add a comment. How to start MediumAction without starting from a Medium. In the MediumAction Iam forwarding to Medium.
Any suggestions to run this program successfully?? Post a copy of the revised Medium. Create a file index. Hi James, As you told I created an index. When I click on the link "Go to Medium.
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