Found 9326 Articles for Object Oriented Programming

The tag is used to loop over nodes in an XML document.AttributeThe tag has the following attributes −AttributeDescriptionRequiredDefaultselectThe XPath expression to be evaluatedYesNonevarName of the variable to store the current item for each loopNoNonebeginThe start index for the iterationNoNoneendThe end index for the iterationNoNonestepThe size of the index increment while iterating over the collectionNoNonevarStatusThe name of the variable in which the status of the iteration is storedNoNoneExampleThe following example shows the use of the tag −           JSTL x:if Tags               Books Info:     ... Read More

The tag evaluates a test XPath expression and if it is true, it processes its body. If the test condition is false, the body is ignored.AttributeThe tag has the following attributes −AttributeDescriptionRequiredDefaultselectThe XPath expression to be evaluatedYesNonevarName of the variable to store the condition's resultNoNonescopeScope of the variable specified in the var attributeNoPageExampleFollowing is an example that show the use of the tag −           JSTL x:if Tags               Books Info:                           ... Read More

A RowId is a built-in type of SQL which is an address of a row in a table of a database. The RowId interface of the java.sql package maps with the SQL ROWID value.RowId values are unique for every row and they are the fastest way to access a row. You cannot use this as a primary key of a table.Retrieving RowId objectsYou can retrieve the RowId of a particular row using the getRowId() method of the ResultSet, CallableStatement, PreparedStatement interfaces.This method accepts a String value representing a column label or, an integer value representing the column index and returns ... Read More

The tag sets a variable to the value of an XPath expression.If the XPath expression results in a boolean, tag sets a java.lang.Boolean object; for a string, java.lang.String; and for a number, java.lang.Number.AttributeThe tag has the following attributes −AttributeDescriptionRequiredDefaultvarA variable that is set to the value of the XPath expressionYesBodyselectThe XPath expression to be evaluatedNoNonescopeScope of the variable specified in the var attributeNoPageExampleFollowing example will show how to use the tag −           JSTL Tags               Books Info:           ... Read More

To process an SQL statement, you need to follow the steps given below:Establish the connection.Create a statement.Execute the statement/query.Process the result.Close the connection.Establishing a ConnectionTo process SQL statements first of all you need to establish connection with the desired DBMS or, file System or, other data sources.To do so, Register the JDBC driver class, corresponding to the DataSource you need to the DriverManager using the registerDriver() method.Driver myDriver = new com.mysql.jdbc.Driver(); DriverManager.registerDriver(myDriver);This method accepts an object of the Driver class; it registers the specified Driver with the DriverManager.You can also register the driver using the forName() method. This method loads ... Read More

The tag displays the result of an XPath expression. It functions the same as JSP syntax.AttributeThe tag has the following attributes −AttributeDescriptionRequiredDefaultselectXPath expression to evaluate as a string, often using XPath variablesYesNoneescapeXmlTrue if the tag should escape special XML charactersNotrueExampleLet us take an example which will cover the tags (a) , (b) .           JSTL x:out Tags               Books Info:                                                 ... Read More

The tag is used to parse the XML data specified either via an attribute or in the tag body.AttributeThe tag has the following attributes −AttributeDescriptionRequiredDefaultvarA variable that contains the parsed XML dataNoNonexmlText of the document to parse (String or Reader)NoBodysystemIdThe system identifier URI for parsing the documentNoNonefilterThe filter to be applied to the source documentNoNonedocXML document to be parsedNoPagescopeScope of the variable specified in the var attributeNoPagevarDomA variable that contains the parsed XML dataNoPagescopeDomScope of the variable specified in the varDom attributeNoPageExampleThe following example shows how parse can be used to read the external XML file −We have ... Read More

The JSTL XML tags provide a JSP-centric way of creating and manipulating the XML documents. Following is the syntax to include the JSTL XML library in your JSP.The JSTL XML tag library has custom tags for interacting with the XML data. This includes parsing the XML, transforming the XML data, and the flow control based on the XPath expressions.Before you proceed with the examples, you will need to copy the following two XML and XPath related libraries into your \lib −XercesImpl.jar − Download it from https://www.apache.org/dist/xerces/j/xalan.jar − Download it from https://xml.apache.org/xalan-j/index.htmlRead More

Not all the databases support batch processing therefore before proceeding with batch updates in your application. You need to verify whether the database you are trying to communicate supports batch processing/batch updates or not.You can do so using the supportsBatchUpdates() method of the DatabaseMetaData interface.Follow the steps given below:Register the driver class using the registerDriver() method of the DriverManager class. Pass the driver class name to it, as a parameter.Connect to the database using the getConnection() method of the DriverManager class. Passing URL (String), username (String), password (String) as parameters to it.Create a DatabaseMetaData object using the getMetaData() method of ... Read More

The tag is used to group the and tags into transactions. You can put as many and tags as statements inside the tag to create a single transaction.It ensures that the database modifications performed by the nested actions are either committed or rolled back if an exception is thrown by any nested action.AttributeThe tag has the following attributes −AttributeDescriptionRequiredDefaultdataSourceDatabase connection to use (overrides the default)NoDefault databaseisolationTransaction isolation (READ_COMMITTED, READ_UNCOMMITTED, REPEATABLE_READ, or SERIALIZABLE)NoDatabase’s defaultExampleTo start with the basic concept, let us create a Students table in the TEST database and create a few records ... Read More