We think you have liked this presentation. If you wish to download it, please recommend it to your friends in any social system. Share buttons are a little bit lower. Thank you!
Presentation is loading. Please wait.
Published byKareem Grays
Modified about 1 year ago
Java™ How to Program, 9/e © Copyright by Pearson Education, Inc. All Rights Reserved.
A class can have references to objects of other classes as members. This is called composition and is sometimes referred to as a has-a relationship. Example: An AlarmClock object needs to know the current time and the time when it’s supposed to sound its alarm, so it’s reasonable to include two references to Time objects in an AlarmClock object. © Copyright by Pearson Education, Inc. All Rights Reserved.
Every class in Java has the methods of class Object (package java.lang ), one of which is the finalize method. Rarely used because it can cause performance problems and there is some uncertainty as to whether it will get called. Every object uses system resources, such as memory. Need a disciplined way to give resources back to the system when they’re no longer needed; otherwise, “resource leaks” might occur. The JVM performs automatic garbage collection to reclaim the memory occupied by objects that are no longer used. When there are no more references to an object, the object is eligible to be collected. This typically occurs when the JVM executes its garbage collector. © Copyright by Pearson Education, Inc. All Rights Reserved.
So, memory leaks that are common in other languages like C and C++ (because memory is not automatically reclaimed in those languages) are less likely in Java, but some can still happen in subtle ways. Other types of resource leaks can occur. An application may open a file on disk to modify its contents. If it does not close the file, the application must terminate before any other application can use it. © Copyright by Pearson Education, Inc. All Rights Reserved.
The finalize method is called by the garbage collector to perform termination housekeeping on an object just before the garbage collector reclaims the object’s memory. Method finalize does not take parameters and has return type void. A problem with method finalize is that the garbage collector is not guaranteed to execute at a specified time. The garbage collector may never execute before a program terminates. Thus, it’s unclear if, or when, method finalize will be called. For this reason, most programmers should avoid method finalize. © Copyright by Pearson Education, Inc. All Rights Reserved.
1 l Basics of Recursion l Programming with Recursion Recursion.
Chapter 7: Deadlocks. The Deadlock Problem System Model Deadlock Characterization Methods for Handling Deadlocks Deadlock Prevention Deadlock Avoidance.
8 Copyright © 2005, Oracle. All rights reserved. Object Life Cycle and Inner Classes.
The. of and a to in is you that it he for.
Pearson Education, Inc. All rights reserved. 1.. Exception Handling.
Objects and Classes Part II CIS 61. Constructors We saw before two ways that member functions can be used to give values to the data items in an object.
Of. and a to the in is you that it at be.
Chapter 22 Implementing lists: linked implementations.
Chapter 11 Separate Compilation and Namespaces. Copyright © 2006 Pearson Addison-Wesley. All rights reserved Learning Objectives Separate Compilation.
Introduction to Java 2 Programming Lecture 3 Writing Java Applications, Java Development Tools.
Copyright © 2002 Pearson Education, Inc. Slide 1.
The. of and a to in is you that it he was.
Lecture Computer Science I - Martin Hardwick Making our programs more flexible rSo far we have largely programmed using l Arrays of integers l Arrays.
Chapter 7 Constructors and Other Tools. Copyright © 2006 Pearson Addison-Wesley. All rights reserved. 7-2 Learning Objectives Constructors Definitions.
Copyright © 2008 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Chapter 10 Servlets and Java Server Pages.
Copyright © 2003 Pearson Education, Inc. Slide 1.
High Frequency Words List A Group 1. the of and.
Chapter 5 Deadlocks. Contents What is deadlock? What is deadlock? Characterization Characterization Resource allocation graph Resource allocation graph.
Chapter 17 Failures and exceptions. This chapter discusses n Failure. n The meaning of system failure. n Causes of failure. n Handling failure. n Exception.
Java Packages CSci 1130 Intro to Computer Programming with Java Instructor Tatyana Volk.
Mr. Wortzman. So far, we have gotten all our input and written all our output to the console In reality, this is somewhat uncommon Instead, we often.
Dolch Words the of and to a in that is was.
I/O means Input and Output. One way: use standard input and standard output. To read in data, use scanf() (or a few other functions) To write out data,
Chapter 2 Section 3. Objectives 1 Copyright © 2012, 2008, 2004 Pearson Education, Inc. More on Solving Linear Equations Learn and use the four steps for.
Introduction Types of Errors Exceptions Exception Handling Common JAVA Exceptions Syntax of Exception Handling Code Example: Divide by Zero.
Lecture 5: Interfaces. concept An interface is a way to describe what classes should do, without specifying how they should do it. It’s not a class but.
Liang, Introduction to Java Programming, Eighth Edition, (c) 2011 Pearson Education, Inc. All rights reserved Chapter 4 Loops.
Arrays 1 -Based on slides from Deitel & Associates, Inc. - Revised by T. A. Yang.
© 2016 SlidePlayer.com Inc. All rights reserved.