since its introduction in java 8, the stream api has become a staple of java development. the basic operations like iterating, filtering, mapping sequences of elements are deceptively simple to use. but these can also be overused and fall into some common pitfalls. to get a better understandi...
Using assertions we can remove theifandthrowstatement with a singleassertstatement. 3. Enabling Java Assertions Because Java assertions use theassertkeyword, there are no libraries needed or packages to import. Note that prior to Java 1.4 it was perfectly legal to use the word “assert” for na...
A wise man once said you are not a real Java programmer until you've dealt with a null pointer exception. Joking aside, the null reference is the source of many problems because it is often used to denote the absence of a value. Java SE 8 introduces a new class calledjava.util.Optiona...
The Java technology code that uses the above SQL statement to create theADDRESStable looks like the following code. ThedbConnectionis the same as the one shown in the previous code. We simply pass it intocreateTables, create a newStatement, and call theexecutemethod to run the SQL code on ...
Finally construction to it. If you need to handle the case where the Using statement is not successful in acquiring a resource, you can test to see if resourcename is Nothing. Structured Exception Handling Instead of a Using Block If you need finer control over the acquisition of the ...
When you declare several instances in oneusingstatement, they are disposed in reverse order of declaration. You can also use theusingstatement and declaration with an instance of aref structthat fits the disposable pattern. That is, it has an instanceDisposemethod, which is accessible, parameterless...
sql.DriverManager; import java.sql.SQLException; import java.sql.Statement; import java.sql.ResultSet; // assume that conn is an already created JDBC connection (see previous examples) Statement stmt = null; ResultSet rs = null; try { stmt = conn.createStatement(); rs = stmt.executeQuery("...
ResultSet result = statement.executeQuery("SELECT name FROM VEHICLE"); try { while (result.next()) { String name = result.getString(1); // ok. } } finally { result.close(); }The JDBC Standard 2.0 and above contains, in addition to the next() method, other ResultSet methods that ...
sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; import java.sql.Statement; import java.sql.ResultSet; // assume that conn is an already created JDBC connection (see previous examples) Statement stmt = null; ResultSet rs = null; try { stmt = conn.createStatement()...
. This method (inherited from the superclassAdministeredObject) takes two string arguments giving the name and value of the property to be set. The property names for the first argument are defined as static constants in the Message Queue classConnectionConfiguration: for instance, the statement...