Is it possible to load a class by two ClassLoader?

Published by Charlie Davidson on

Is it possible to load a class by two ClassLoader?

Class Loader Rule 1 A class is loaded only once into the JVM. So when a class is loaded into JVM, you have an entry as (package, classname, classloader). Therefore the same class can be loaded twice by two different ClassLoader instances.

What are the different class loaders used by JVM?

When the JVM is started, three class loaders are used:

  • Bootstrap class loader.
  • Extensions class loader.
  • System class loader.

What is the difference between class getResource () and ClassLoader getResource ()?

Class. getResource can take a “relative” resource name, which is treated relative to the class’s package. Alternatively you can specify an “absolute” resource name by using a leading slash. Classloader resource paths are always deemed to be absolute.

Who loads the ClassLoader?

It is implemented by AppClassLoader class. All user classes by default are load by the system class loader. Java ClassLoader are hierarchical and whenever a request is raised to load a class, it delegates it to its parent and in this way uniqueness is maintained in the runtime environment.

Can we create immutable class in Java?

Immutable class in java means that once an object is created, we cannot change its content. In Java, all the wrapper classes (like Integer, Boolean, Byte, Short) and String class is immutable. We can create our own immutable class as well. The class must be declared as final so that child classes can’t be created.

How does JVM load classes?

JVM provides two types of class loaders. One is called bootstrap class loader and another is the user-defined class loader. The bootstrap class loader is rigidly defined in the JVM and loads class files according to the specification. Once a class is loaded, JVM parses it according to the internal data structure.

How do you use class getResource?

Class getResource() method in Java with Examples The method returns the specified resource of this class in the form of URL object. Parameter: This method accepts a parameter resourceName which is the resource to get. Return Value: This method returns the specified resource of this class in the form of URL objects.

What does class getResource do?

The getResource() method of java Class class is used to return the resources of the module in which this class exists. The value returned from this function exists in the form of the object of the URL class.

How does JVM ClassLoader work?

ClassLoader in Java is a class that is used to load class files in Java. Java code is compiled into a class file by javac compiler and JVM executes the Java program, by executing byte codes written in the class file. ClassLoader is responsible for loading class files from file systems, networks, or any other source.

What is difference between immutable and final?

final means that you can’t change the object’s reference to point to another reference or another object, but you can still mutate its state (using setter methods e.g). Whereas immutable means that the object’s actual value can’t be changed, but you can change its reference to another one.

Is String immutable in Java?

Since Strings are immutable in Java, the JVM optimizes the amount of memory allocated for them by storing only one copy of each literal String in the pool.

What’s the difference between class.getresource and classloader?

The ClassLoader version of getResource () on the other hand did find the generated file. From this experience it seems that there is some kind of caching of the directory listing going on. Am I right, and if so, where is this documented?

How is the class loader different from the loadclass method?

It is slightly different from the loadClass method because the class itself is given as a byte array, whereas loadClass needs to find that class to load it.

What’s the difference between classloader resource paths in Java?

Classloader resource paths are always deemed to be absolute. The first call searches relative to the .class file while the latter searches relative to the classpath root.

Is it safe to reload classloader in Java?

ClassLoader leaks can be way too dangerous. Every time we do a redeployment or add enhancements at the runtime in our application, ClassLoader will load a class, never reload or unload a class.

Categories: Users' questions