DataInputStream and DataOutputStream

• DataInputStream is used to read the primitive datatypes from an input source.
• DataOutputStream is used to write the primitive datatypes to an output source.

• We use the writeUTF() function to write a string to the output stream using UTF-8 encoding in portable manner.

• We use the readUTF() function to read a string of an input stream where UTF-8 encoding is used.

• These streams are located in java.io package.

AWT(Abstract Window Toolkit)

• AWT is an API(Application Programming Interface) for creating Graphical User Interface(GUI) that allows programmers to develop windows based applications.

• Java AWT components are platoform dependent.i.e components are displayed according to the view of OS.

• AWT is heavyweight. i.e it's components are using the resources of OS.

• java.awt package is used.

                      ACTIONLISTENER INTERFACE
  

• ActionListener in Java is an Interface that is responsible for handling action events such as when the user clicks the Button.

• The java ActionListener is notified whenever you click on the button or the menu button.

• It is notified against ActionEvent.

• ActionListener interface is found in java.awt.event package.

• The class which process the ActionEvent should implement the interface ActionListener.

• The object of the class must be registered using addActionListener(instanceoflistenerclassmethod) with a component.

                                           **JAVA-3rd programming questions**
  

• Write a java program to write a name, rollno, faculty and address of a student in a text file "detail.dat" that keep asking for the data until the user press n key to exit.

            **Answer:- Student.java**
  

• A data file "detail.dat" contains name, rollno, faculty and address of 3 students. Write a progaram to display only those records who belong to software faculty.

            **Answer:- Student2.java**
  

• Write a Java Program to fulfil the following requirements in which the simple form is created with a textfield and a button.

             **Answer:- GUIForm.java**

• Write a Java Program to fulfil the following requirements in which the form contains a TextField, a Button and a Label. When we give the integer value to the textField, show the assigned integer value is even or odd in label as shown in below.

               **Answer:- ActionListener1st.java**