1Z0-811 Java Development and Deployment 4

Question 1

Which `jar` command option lists the contents of an existing JAR file?

Accepted Answer

jar --list --file app.jar

Answer

jar --extract --file app.jar

Answer

jar --create --file app.jar

Answer

jar --update --file app.jar

Question 2

When module-info.java contains `uses com.example.Printer;`, what does this indicate?

Accepted Answer

The module is a consumer of the Printer service via ServiceLoader

Answer

The module provides an implementation of Printer

Answer

The module exports the Printer interface

Answer

The module requires the com.example module

Question 3

Which Java 11 feature allows running a single-file source program without explicitly compiling it first?

Accepted Answer

java Hello.java

Answer

javac Hello.java && java Hello

Answer

jar -cf Hello.jar Hello.java

Answer

jshell Hello.java

Question 4

What does the `--show-module-resolution` JVM flag output during startup?

Accepted Answer

A trace of which modules are being resolved and in what order

Answer

A list of all exported packages

Answer

The module's dependency graph as a PNG

Answer

The version of each resolved module

Question 5

Which directory inside a module source tree conventionally holds the `module-info.java` file?

Accepted Answer

The root of the module's source directory

Answer

src/main/resources/

Answer

META-INF/

Answer

src/module/

Question 6

What is the role of the `java.base` module in the Java module system?

Accepted Answer

It is the foundational module that every other module implicitly requires

Answer

It must be explicitly listed in every module-info.java

Answer

It contains only the java.lang package

Answer

It is an optional module for backward compatibility

Question 7

Which option passed to `javac` enables preview features in Java 11?

Accepted Answer

--enable-preview combined with --release 11

Answer

--preview-features

Answer

--experimental

Answer

--enable-preview alone