hi there,
I'm looking for an solution to generate a checksum for any type of java object, which remains the same for every exection of an application which produces the same object.
I tried it with object.hashcode(), but as I read in the api
....This integer need not remain consistent from one execution of an application to another execution of the same application.
thank you, best regard alex
I have a Java application complied to a collection of jars that I want to make installable on Ubuntu and SuSE. I Want the installer to be able to check for the JRE, register a file association and be able to load a website on un-install.
I understand Ubuntu and SuSE are based on different architectures, so is there a consistent way to do this?
Does anyone have an advice on utilities to use or guides to read to help me achieve what I'm trying to do.
Using JNI can we pass custom data types from Java to C (or vice versa)? I see a mapping of primitive datatypes to types in C however not too sure if we can send across our own data types (e.g. Send across or return an Employee object or something!).
How would one go about proving to management that a batch reformat of all .java files in a large code base (to place the code in compliance with the company's coding standards) is safe and will not affect functionality.
The answers would have to appease the non-technical and the technical alike.
This problem occurs over and over. I have some complicated object, such as a Cat, which has many properties, such as age, favorite cat food, and so forth.
A bunch of Cats are stored in a Java Collection, and I need to find all the Cats that are aged 3, or those whose favorite cat food is Whiskas. Surely, I can write a custom method that finds those Cats with a specific property, but this gets cumbersome with many properties; is there some generic way of doing this?
Hi,
After some serious googleing I found out that the RandomAccessFile-class is not thread-safe. Now I could use one semaphore to lock all reads and writes but I don't think that performs very well. In theory it should be possible to do multiple reads and one write at a time.
How can I do this in Java? Is it possible at all?
Thanks!
Given the following code:
public class Test {
public void method(Object o){
System.out.println("object");
}
public void method(String s) {
System.out.println("String");
}
public void method() {
System.out.println("blank");
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
Test test=new Test();
test.method(null);
}
}
Java prints "String". Why is this the case?
I need to invoke .jar file in separate JVM from another java application, and it very CPU-consuming, so it should run with background priority in order not to affect the rest of the system. Is there any cross-platform method to do this?
I need to use a few Cyrillic characters in a Java file and in order for Eclipse to allow me to do so I need to change the encoding for that file (currently to UTF-8).
Are there any possible problems that this could cause?
I haven't found many ways to increase the performance of a Java application that does intensive XML processing other than to leverage hardware such as Tarari or Datapower. Does anyone know of any open source ways to accelerate XML parsing?
Hi,
After I read Bloch's discussion http://www.infoq.com/news/2010/04/bloch_java_future
I started to think about "Do I have to switch to scala for new web developements" or is java preferred in all cases. What is your opinion ?
Thanks,
I am actually new to java programming and am finding it difficult to take integer input and storing it in variables...i would like it if someone could tell me how to do it or provide with an example like adding two numbers given by the user..
Any tips or best practices for unit testing Google Wave robots written in Java? I'm expecting to deploy on AppEngine, if that helps. I'm a fan of TDD but new to both Wave Robots and AppEngine, so I'm hoping to use TDD to help me explore the design space.
Hello,
I'm creating a java web application runing on a Tomcat server.
One of the functions fill in a StringBuffer variable with data.
At the end, I would like to propose the user to download the generated content packaged in a text file. This without having to store the file on the server.
I've been searching for a code snippet but couldn't find anything corresponding ...
I hope I've been clear enough on my problem.
Thanks in advance,
What's the easiest way to create a simple HTTP server with Java? Are there any libraries in commons to facilitate this? I only need to respond to GET/POST, and I can't use an application server.
What's the easiest way to accomplish this?
I'm using a MySQL database and accessing it through Java.
PreparedStatement prep1 = this.connection.prepareStatement("UPDATE user_table
SET Level = 'Super'
WHERE Username = ?");
prep1.setString(1, username);
The update statement above works fine however I'd like to get the number of rows affected with this statement. Is this possible please?
I want to make a java application software which give the current status/information of the running computer. So, for this, is there any inbuilt/extrnal library present or not?
Can anyone give a simple code which will just. "What is the current status of laptop battery?" or "Is AC adapter is pluged in or not?"
Please help me.
Hi,
I'm a beginner in java. I want the logic of the small program.
I have two arrays
array = {a1,a2,a3,a4,a5,,,,,,,,,an}
and
array2 = {b1,b2,b3,b4,,,,,,,,,,,bn}
I want string as:
a1b1,a2a3b2b3,a4a5a6b4b5b6,..........an
Please tell me what will be the logic.
how to do the 3D Animation in java? what are the packages to be needed? i am very newbie about this topic. Sample Code, Tutorials and articles are more thankful. Tell me how i have to start please?
NOTE: its for Mobile Appication.
I have been working with the Swing library for a long time, I'm working on a new project for school and due to the nature of the program it can't look like a generic/boring swing gui. So my question is does anyone know of an interesting java gui library that is not swing or awt?
If I wanted a single word that meant "conforming to Java language conventions", what would that be? Python has the term "pythonic". Would it be "javaish"?
I have a problem with java instanceof. I have a class called Employee and several others that extend this one, for example - Manager. I also created another class,EmployeeStockPlan, where I wanted to test if instanceof is finding which object I am using. But when I am calling a method from the new class, I have this error: The method grantStock(Manager) is undefined for the type Loader. Sorry, I am somehow new to some thing in java, I hope I am not asking dumb questions.
The Employee class:
package com.example.domain;
public class Employee {
private int empId;
private String name;
private String ssn;
private double salary;
public Employee(int empId, String name, String ssn, double salary) { // constructor
// method;
this.empId = empId;
this.name = name;
this.ssn = ssn;
this.salary = salary;
}
public void setName(String newName) {
if (newName != null) {
this.name = newName;
}
}
public void raiseSalary(double increase) {
this.salary += increase;
}
public String getName() {
return name;
}
public double getSalary() {
return salary;
}
public String getDetails() {
return "Employee id: " + empId + "\n" + "Employee name: " + name;
}
}
The Manager class:
package com.example.domain;
public class Manager extends Employee {
private String deptName;
public Manager(int empId, String name, String ssn, double salary,
String dept) {
super(empId, name, ssn, salary);
this.deptName = dept;
}
public String getDeptName() {
return deptName;
}
public String getDetails() {
return super.getDetails() + "\n" +
"Department: " + deptName;
}
}
The EmployeeStockPlan class:
package com.example.domain;
public class EmployeeStockPlan {
public void grantStock(Employee e) {
// nothing calculated, just simulating;
System.out.println("This is an employee!");
if (e instanceof Manager) {
// process Manager stock grant
System.out.println("This is a manager!");
} else {
// error - instance of Engineer?
System.out.println("Not an engineer!");
}
return;
}
}
The main class:
EmployeeStockPlan esp = new EmployeeStockPlan();
Manager m = new Manager (12421, "Manager1", "111-4254-521", 2430, "Marketing1");
grantStock(m);