cmd/designated folder/ jar cf name.jar *.* Create a file: META-INF/MANIFEST.MF Add a line: Main-Class: com.myco.calc.CalculatorDemo Include META-INF/MANIFEST.MF in calculator.jar Run with java -jar calculator.jar
This is useful in domain or value object class to compare different object fields in an equals method
public class DomainObject {
//protected because only inheriting domain classes can use it
protected boolean isPropertyEqual(Object compare1, Object compare2) {
// go here if compare1 is null, i.e. test cases 1 & 3
if (compare1 == null) {
if (compare2 != null) {
return false;
}
//go here if compare1 is not null, i.e. test cases 2 & 5
} else if (!compare1.equals(compare2)) {
return false;
}
return true; //test cases 1 & 4
}
public static void main(String[] args) {
DomainObject d = new DomainObject();
Print(d.isPropertyEqual(null, null)); //test case 1
Print(d.isPropertyEqual(“abc”, null)); //test case 2
Print(d.isPropertyEqual(null, “abc”)); //test case 3
Print(d.isPropertyEqual(“abc”, “abc”));//test case 4
Print(d.isPropertyEqual(“abc”, “cba”));//test case 5
}
public static void Print(boolean bol){
System.out.println(bol);
}
}
The above class must be abstract. It was not tagged abstract to demo via the main() method by creating a new DomainObject().
The above method can be used in an extending class like
public class Security extends DomainObject implements Serializable {
private String id;
//skipping other methods like getter/setter, toString, etc
public boolean equals(Object obj) {
if (this == obj) {
return true;
}
if (!(obj instanceof Security)) {
return false;
}
//calling super class handy method we just created
return isPropertyEqual(this.id, ((Security) obj).getId());
}
public int hashCode() {
return id.hashCode();
}
}