[INFO] Image will be built as hello-howtodoinjava/hello-docker:latest [INFO] [INFO] Step 1/5 : FROM openjdk:8-jdk-alpine [INFO] Pulling from library/openjdk [INFO] Digest: sha256:2b1f15e04904dd44a2667a07e34c628ac4b239f92f413b587538f801a0a57c88 [INFO] Status: Image is up to dat...
Example: Using newInstance() method of Class class In the program given below, we created an object using anewInstance()method of aClassclass. In this method instead of thenewkeyword, we use the method, and then this method will create an instance of a class and it will be stored to th...
However, it’s not without its limitations. TheCollections.sort()method sorts in ascending order by default, and it can’t handle null values. If you try to sort a list with null values, it will throw aNullPointerException. Moreover, it may not work as expected with custom objects, unle...
* Method to add the data binding and validation logics * to the registration form */ public void addBindingAndValidation() { BeanValidationBinder<UserDetails> binder = new BeanValidationBinder<>(UserDetails.class); binder.bindInstanceFields(registrationForm); // A custom validator for password fiel...
Don’t create setter method for any instance variables, hence there will be no explicit way to change state of instance variables. Initialize all variables in constructor : You can initialize variables in constructor. You need to take special care while working with mutable object. You need to ...
the string is added to the pool. In more precise terms, thejava.lang.String.internmethod returns a string’scanonical representation; the result is a reference to the same class instance that would be returned if that string appeared as a literal. If an application interns a large number of...
For instance, let’s consider we have the followingKey–Valuepair: {first=1, second=2, two=2} Here, the value “2” is repeated twice for different keys. In these cases, we can use thegroupingBy()method to implement a cascaded “group by” operation on theValueobjects: ...
First of all, the Manager interface has the getContainer and setContainer methods to associate a Manager implementation with a context. The createSession method creates a Session object. The add method adds a Session instance to the session pool and the remove method removes the Session object fro...
In this chapter you will learn: How to define class instance methods Define class instance methodsMethods are functions that manipulate the data defined by the class. Your program will interact with a class through its methods. The general form of a method is shown here: access...
JNDI Location: Action Framework expects EJBs to be deployed to the default location of /ejb. The mappedName annotation of the Session bean must preceded by a ejb/ Binary document: In order to send documents, the Java method should include a specific Java data type (javax.activation.DataHandler...