The isSealed(URL) method of java.lang.Package class is used to check if this package is sealed or not, with respect to the specified URL. The method returns the result as a boolean value.
Syntax: 
 
public boolean isSealed(URL url)
Parameter: This method does not accept any parameter.
Return Value: This method returns the result as a boolean value.
Below programs demonstrate the isSealed(URL) method.
Example 1:
 
Java
| // Java program to demonstrate// isSealed(URL) methodimportjava.net.*;publicclassTest {    publicstaticvoidmain(String[] args)        throwsMalformedURLException    {        // returns the Package        // object for this package        Package myPackage            = Package.getPackage("java.lang");        System.out.println(            "Package represented by myPackage: "            + myPackage.toString());        URL url        // check if this package is sealed or not        // using isSealed(URL) method        System.out.println(            "Is this package sealed or not: "            + myPackage.isSealed(url));    }} | 
Package represented by myPackage: package java.lang, Java Platform API Specification, version 1.8 Is this package sealed or not: false
Example 2:
 
Java
| // Java program to demonstrate// isSealed(URL) methodimportjava.net.*;publicclassTest {    publicstaticvoidmain(String[] args)        throwsMalformedURLException    {        // returns the Package        // object for this package        Package myPackage            = Package.getPackage("java.io");        System.out.println(            "Package represented by myPackage: "            + myPackage.toString());        URL url        // check if this package is sealed or not        // using isSealed(URL) method        System.out.println(            "Is this package sealed or not: "            + myPackage.isSealed(url));    }} | 
Package represented by myPackage: package java.io, Java Platform API Specification, version 1.8 Is this package sealed or not: false
Reference: https://docs.oracle.com/javase/9/docs/api/java/lang/Package.html#isSealed–
 


 
                                    







