Rules for Overloading the Method in Java

  1. You can overload a method by changing its signature. method signature is made of number of arguments, type of arguments and order of arguments.
  2. Return type is not a part of method signature, so changing method return type means no overloading unless you change argument with return type.
  3. A method can be overloaded in the same class or in a subclass. if class A defines a display(float i) method, the subclass B could define a display(String s) method without overriding the super-class version that takes an int. So two methods with the same name but in different classes can still be considered overloaded, if the subclass inherits one version of the method and then declares another overloaded version in its class definition.

Popular posts from this blog

Resolve OutOfMemoryError With ExcelExport : Export Excel Utility with Apache POI Stream API (SXSSF)

                                 Whenever we try to export excel of huge data (for ex: around 200000-300000 records), most of the time we end up with OutOfMemoryError:JavaHeapSpace. And also consuming more time to process or export that much of data. Main reason to this kind of problem is that, the prior version of Apache POI (prior to 3.8) will not provide proper solution for this kind of situations and also we have other issues with the API designed with those versions. Even I had faced issues of not supporting more than 65000 rows of data during exporting excel with prior versions of POI. But with the version 3.8 and higher they come with solutions for all these problems. To resolve Memory issue and performance issue of Excel Export they have utilized stream API to design their API to support huge data export and performance issues. With stream API we can flush only few rows of data into the Memory and reamining we can flush to the hard memory (permanent Memory). In this examp
Read more

Be-Aware of the Performance of the String Concatenation...

                  The string concatenation operator (+) is a convenient way to combine a few strings into one. It is fine for generating a single line of output or for constructing the string representation of a small, fixed-size object, but it does not scale. Using the string concatenation operator repeatedly to concatenate n strings requires time quadratic in n. It is an unfortunate consequence of the fact that strings are immutable. When two strings are concatenated, the contents of both are copied. For example, consider the following method that constructs a string representation of a billing statement by repeatedly concatenating a line for each item: // In-appropriate use of string concatenation - Hits Performance drastically! public String statement() {      String res = "";      for (int i = 0; i < numOfItems(); i++)       res += lineOfItem(i); // String concatenation       return res; }                   This method performs very slow if the number of
Read more

How To Resolve "Java compiler level does not match the version of the installed Java project facet." Issue in Eclipse, STS tool or Eclipse Based Tools

Image
                  I have faced this issue during the Java 7 upgrade from Java 6 into one of our application. You will face this issue suppose if your application or project built on lower versions of Java (in my case it is Java 1.6) and you are trying to upgrade it to the Higher versions of Java (in My case it is Java 1.7), then Eclipse will throw this error in the tool. You will face this error even after changing the compiler version from build path. To fix this issue Follow the Below Mentioned Steps. 1.  Open the ' Markers ' Tab at the bottom of the eclipse or STS tool beside the ' Properties ' Tab. (as shown in the below figure) 2. Right Click on the Error as mentioned in the below figure. in The context menu click on the ' Quick Fix ' item as shown below in the figure. 3. Select the correct Java Project Facet from the ' Quick Fix ' Window. and click on the ' Finish ' Button. 4.  After Clicking on '
Read more