How to check whether java is installed on the computer?

Question

I have a Java windows application that runs on a client machine. Can anyone tell me how to check whether a required JRE is installed on the machine by Java program? 

Answer 1

 You can do it programmatically like below: 

@Test

public void javaVersion() {

    System.out.println(System.getProperty("java.version"));

    System.out.println(System.getProperty("java.runtime.version"));

    System.out.println(System.getProperty("java.home"));

    System.out.println(System.getProperty("java.vendor"));

    System.out.println(System.getProperty("java.vendor.url"));

    System.out.println(System.getProperty("java.class.path"));

}

The output will be: 

1.7.0_17

1.7.0_17-b02

C:\workspaces\Oracle\jdk1.7\jre

Oracle Corporation

http://java.oracle.com/

C:\workspaces\Misc\Miscellaneous\bin; ...

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