What are the predefined abstract classes in Java?

-

What are the predefined abstract classes in Java?




There are many but some of them are AbstractMap<K,V>, AbstractMap<K,V>,AbstractCollection<E>,AbstractList<E>  ext.

Comments

Post a Comment

Popular posts from this blog

How do I create an array of a string?

-
How do I create an array of a string? Here is the example code. public class ArrayDemo { public static void main(String[] args) { String[] strArray = new String[2]; strArray[0] = "Hello"; strArray[1] = "World !"; System.out.println(strArray[0] +" "+strArray[1]); } } Output: Hello World !
Read more

How to know the compiled version of jar file or class file?

-
How to know the compiled version of jar file or class file? To know the complied version of the jar file or class file below is the code. You have to run the MainClass and pass the file name in the argument. You have to put jar or class file in same path of MainClass file. import java.io.DataInputStream; import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.io.InputStream; import java.nio.file.CopyOption; import java.nio.file.Files; import java.nio.file.Path; import java.nio.file.Paths; import java.nio.file.StandardCopyOption; import java.util.Enumeration; import java.util.jar.JarEntry; import java.util.jar.JarFile; import java.util.logging.Logger; public class CheckVersionUtil { private static final Logger LOGGER = Logger.getLogger(CheckVersionUtil.class.getSimpleName()); public static void copyToTemp(String destinationDir, String srcFile) throws IOException { LOGGER.info(...
Read more

Explain briefly about POJO in Java?

-
Explain briefly about POJO in Java? POJO is Plain old java object. The class with its private attributes and the having the getter and setter method. these methods are public so any class from out side can access this attributes via the methods only not directly. Example : import java.util.Date; public class Student { private int id; private String name; private Date dob; public Date getDob() { return dob; } public void setDob(Date dob) { this.dob = dob; } public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } } Here you can see the Student class POJO with id , name and DOB attributes and having the getter and setter methods.
Read more