jbang-catalog

My collection of JBang scripts.

It contains various sample scripts and test templates for JUnit 4, JUnit 5 and TestNG to help in writing tests for JBang scripts.

Table of contents

General

• Install JBang
• Install JBang completion script
• Generate the completion script for a JBang script

JBang Scripts

• Ssh
• Sort
• Links
• Html
• SizeOf
• GitClone
• GitGet
• WhatsNewInJava
  • Lists the changes made for Stream feature in Java 8 for Iterable, Collection and List classes
  • Lists Optional, Stream and Collectors changes introduced since Java 8
  • Lists the changes introduced to java.nio.file package in Java 8
  • Lists the changes made to java.lang.Process in Java 9
  • Lists the classes having changed in Java 9 in the java.time package
  • List the changes made in Java 11 for strings
  • List the java.lang.Integer, java.lang.Long ... methods made deprecated in Java 9
  • List the deprecated methods in package java.util.concurrent.atomic
  • List the deprecated methods of java.lang.Thread
• Vote
• StatusCode

JBang CLI Templates

• CLI templates

JBang Test Templates

• JUnit 4 template
• JUnit 5 template
• TestNG template

Install JBang

curl -Ls https://sh.jbang.dev | bash -s -

Then:

export PATH=$HOME/.jbang/bin:$PATH

And if you want to define the editor:

export JBANG_EDITOR=idea

Install JBang completion script

jbang completion \
    | sed 's/+o default/-o default/' \
    | sudo tee /etc/bash_completion.d/jbang

Generate the completion script for a JBang script

For example with WhatsNewInJava.java:

jbang build WhatsNewInJava.java
java -classpath $(jbang info classpath WhatsNewInJava.java) \
    picocli.AutoComplete --force --name=whats-new-in-java WhatsNewInJava
sudo cp whats-new-in-java_completion /etc/bash_completion.d

Ssh

A basic SSH client.

Written with Java 11, Apache Mina, JBang and Picocli.

jbang ssh@grumpyf0x48 --help

Usage: Ssh [-hV] [-a=<authenticationTimeout>] [-c=<connectionTimeout>]
           [-i=<identityFile>] [-p=<password>] [--port=<port>] <destination>
           [<command>...]
A basic SSH client
      <destination>    Destination to reach (format: user@hostname)
      [<command>...]   Command to execute and its parameters
  -a, --authentication-timeout=<authenticationTimeout>
                       Authentication timeout in seconds (default: 30)
  -c, --connection-timeout=<connectionTimeout>
                       Connection timeout in seconds (default: 30)
  -h, --help           Show this help message and exit.
  -i, --identity=<identityFile>
                       Identity file
  -p=<password>        Password
      --port=<port>    Port (default: 22)
  -V, --version        Print version information and exit.

Sample use

jbang ssh@grumpyf0x48 -i ~/.ssh/id_rsa pi@192.168.0.108 ls /home

Sort

A sample sort program to illustrate Java stream and Array sort use.

Written with JBang and Picocli.

jbang sort@grumpyf0x48 --help

Usage: Sort [-himnrV] [<elements>...]
A sample sort program to illustrate Java stream and Array sort use
      [<elements>...]        Elements to sort
  -h, --help                 Show this help message and exit.
  -i, --ignore-case          Enable ignore case
  -m, --human-numeric-sort   Enable human numeric sort
  -n, --numeric-sort         Enable numeric sort
  -r, --reverse              Enable reverse sort
  -V, --version              Print version information and exit.

Sample use

jbang sort@grumpyf0x48 -r -m $(exa -l ~/Downloads | cut -d " " -f 2 | xargs)

Links

A program to retrieve the posts metadata of my former blog archived on https://web.archive.org.

Written with Jsoup, Gson, JBang and Picocli.

jbang links@grumpyf0x48 --help

Usage: Links [-hvV] [-a=<archivedSiteUrl>] [-f=<firstPage>] [-l=<lastPage>]
             [-r=<rootUrl>] <file>
A program to retrieve the posts metadata of my former blog archived on https://web.archive.org
      <file>                 The output file
  -a, --archived-site-url=<archivedSiteUrl>
                             The URL of the archived web Site (default: http:
                               //blog.onkeyboardst.net)
  -f, --first-page=<firstPage>
                             First page to parse (default: 1)
  -h, --help                 Show this help message and exit.
  -l, --last-page=<lastPage> Last page to parse (default: 1)
  -r, --root-url=<rootUrl>   The root URL to parse on https://web.archive.org
                               (default: https://web.archive.
                               org/web/20200211042437)
  -v, --verbose              Enable verbose mode
  -V, --version              Print version information and exit.

Sample use

jbang links@grumpyf0x48 -v -f 1 -l 4 firstPosts.json

Html

A program to build the archive page for my new blog from the posts.json file generated by Links.

Written with Gson, JBang and Picocli.

jbang html@grumpyf0x48 --help

Usage: Html [-hV] -i=<inputFile> -o=<outputFile>
A program to build the archive page for my new blog from the posts.json file generated by Links
  -h, --help         Show this help message and exit.
  -i=<inputFile>     The input file (.json)
  -o=<outputFile>    The output file (.html)
  -V, --version      Print version information and exit.

Sample use

jbang html@grumpyf0x48 -i posts.json -o archive.html

SizeOf

A program to display the memory size of Java primitive types and their corresponding wrapper classes.

Written with OpenJDK jol, JBang and Picocli.

jbang sizeof@grumpyf0x48 --help

Usage: SizeOf [-hV] [<types>...]
A program to display the memory size of Java primitive types and their corresponding wrapper classes
      [<types>...]   The primitive types (default: byte, boolean, char, short,
                       int, float, long, double
  -h, --help         Show this help message and exit.
  -V, --version      Print version information and exit.

Sample use

jbang sizeof@grumpyf0x48

sizeof(byte)=1, sizeof(Byte)=16
sizeof(boolean)=1, sizeof(Boolean)=16

sizeof(char)=2, sizeof(Character)=16
sizeof(short)=2, sizeof(Short)=16

sizeof(int)=4, sizeof(Integer)=16
sizeof(float)=4, sizeof(Float)=16

sizeof(long)=8, sizeof(Long)=24
sizeof(double)=8, sizeof(Double)=24

GitClone

A basic git clone replacement in Java.

Written with jGit, JBang and Picocli.

jbang git-clone@grumpyf0x48 --help

Usage: GitClone [-hnV] [--bare] [-b=<branch>] [-i=<identityFile>] <repository>
                [<directory>]
A basic `git clone` replacement in Java
      <repository>        The repository to clone from
      [<directory>]       The name of a new directory to clone into
  -b, --branch=<branch>   Branch name
      --bare              Make a bare Git repository
  -h, --help              Show this help message and exit.
  -i, --identity=<identityFile>
                          Identity file in PEM format (default: ~/.ssh/id_rsa)
  -n, --no-checkout       No checkout of HEAD is performed after the clone is
                            complete
  -V, --version           Print version information and exit.

The SSH key should be in PEM format.

To convert a private key from OPENSSH to PEM format:

ssh-keygen -p -f ~/.ssh/id_rsa -m pem

Sample use

jbang git-clone@grumpyf0x48 git@github.com:jbangdev/jbang.git /tmp/jbang

GitGet

A command to get one or more files (or directories) from a Git repository.

Written with jGit, JBang and Picocli

It is like git clone but restricted to some files or directories of the repository.

jbang git-get@grumpyf0x48 --help

Usage: GitGet [-hV] [--fresh] [-b=<branch>] [-i=<identityFile>] <repository>
              <directory> <paths>...
A command to get one or more files (or directories) from a Git repository
      <repository>        The repository to clone from
      <directory>         The name of a new directory where to store files
      <paths>...          The file or directory paths to get from the repository
  -b, --branch=<branch>   Branch name
      --fresh             Make a fresh clone of the repository
  -h, --help              Show this help message and exit.
  -i, --identity=<identityFile>
                          Identity file in PEM format (default: ~/.ssh/id_rsa)
  -V, --version           Print version information and exit.

Sample use

jbang git-get@grumpyf0x48 git@github.com:jbangdev/jbang.git ~/jbang-files misc/ src/ readme.adoc

ls -l ~/jbang-files
total 64
drwxrwxr-x 3 user user  4096 mars   7 08:24 misc
-rw-rw-r-- 1 user user 54560 mars   7 08:24 readme.adoc
drwxrwxr-x 4 user user  4096 mars   7 08:24 src

Need to get more files ?

jbang git-get@grumpyf0x48 git@github.com:jbangdev/jbang.git ~/jbang-files examples/ LICENSE

ls -l ~/jbang-files
total 72
drwxrwxr-x 2 user user  4096 mars   7 08:24 examples
-rw-rw-r-- 1 user user  1076 mars   7 08:24 LICENSE
drwxrwxr-x 3 user user  4096 mars   7 08:24 misc
-rw-rw-r-- 1 user user 54560 mars   7 08:24 readme.adoc
drwxrwxr-x 4 user user  4096 mars   7 08:24 src

The previously cloned repository in System.getProperty("java.io.tmpdir") will then be re-used.

WhatsNewInJava

A program to list new methods added, or deprecated ones, in the JDK for a given list of classes.

By default WhatsNewInJava lists new methods added in the 9, 10 and 11 JDK releases.

This program needs the JDK sources to work:

sudo apt-get install openjdk-11-source
cd /usr/lib/jvm/openjdk-11
sudo unzip src.zip

It uses Java Stream functionality, illustrates Spliterator usage and makes use of some Java 1.8, 10 and 11 new features.

Written with Java 11, JBang and Picocli.

jbang whats-new-in-java@grumpyf0x48 --help

Usage: WhatsNewInJava [-abcdhvV] [--all-deprecations] [-m=<module>]
                      [-s=<sourcesPath>] [-r=release]... <classNames>...
Display methods added to a Java class in a given JDK release
      <classNames>...      Class names or regexps
  -a, --not-modified-classes
                           Show all classes even not modified ones (default:
                             false)
      --all-deprecations   Show deprecated methods without 'since' mention
                             (regardless of '--release') (default: false)
  -b, --show-abstract-classes
                           Show abstract classes (default: false)
  -c, --only-class-names   Show only names of modified classes, not their
                             methods (default: false)
  -d, --deprecation        Show deprecated methods instead of added or updated
                             ones (default: false)
  -h, --help               Show this help message and exit.
  -m, --module=<module>    Module (java.base, java.desktop, java.logging ...)
                             where to search classes (default: java.base)
  -r, --release=release    JDK release (1.8, 9, 10, 11 ... or ALL) (default: 9,
                             10, 11)
  -s, --source-path=<sourcesPath>
                           JDK sources path (default: /usr/lib/jvm/openjdk-11)
  -v, --verbose            Activate verbose mode (default: false)
  -V, --version            Print version information and exit.

Sample use

Lists the changes made for Stream feature in Java 8 for Iterable, Collection and List classes

jbang whats-new-in-java@grumpyf0x48 --source-path /usr/lib/jvm/openjdk-11 --release 1.8 java.lang.Iterable java.util.Collection java.util.List

public interface Iterable<T> // since 1.5
{
    default void forEach(Consumer<? super T> action); // since 1.8
    default Spliterator<T> spliterator(); // since 1.8
}

public interface Collection<E> extends Iterable<E> // since 1.2
{
    default boolean removeIf(Predicate<? super E> filter); // since 1.8
    default Spliterator<E> spliterator(); // since 1.8
    default Stream<E> stream(); // since 1.8
    default Stream<E> parallelStream(); // since 1.8
}

public interface List<E> extends Collection<E> // since 1.2
{
    default void replaceAll(UnaryOperator<E> operator); // since 1.8
    default void sort(Comparator<? super E> c); // since 1.8
    default Spliterator<E> spliterator(); // since 1.8
}

Lists Optional, Stream and Collectors changes introduced since Java 8

jbang whats-new-in-java@grumpyf0x48 --source-path /usr/lib/jvm/openjdk-11 java.util.Optional java.util.stream.Stream java.util.stream.Collectors

public final class Optional<T> // since 1.8
{
    public void ifPresentOrElse(Consumer<? super T> action, Runnable emptyAction); // since 9
    public Optional<T> or(Supplier<? extends Optional<? extends T>> supplier); // since 9
    public Stream<T> stream(); // since 9

    public T orElseThrow(); // since 10

    public boolean isEmpty(); // since 11
}

public interface Stream<T> extends BaseStream<T, Stream<T>> // since 1.8
{
    default Stream<T> takeWhile(Predicate<? super T> predicate); // since 9
    default Stream<T> dropWhile(Predicate<? super T> predicate); // since 9
    public static<T> Stream<T> ofNullable(T t); // since 9
    public static<T> Stream<T> iterate(T seed, Predicate<? super T> hasNext, UnaryOperator<T> next); // since 9
}

public final class Collectors // since 1.8
{
    public static <T, U, A, R> Collector<T, ?, R> flatMapping(Function<? super T, ? extends Stream<? extends U>> mapper, Collector<? super U, A, R> downstream); // since 9
    public static <T, A, R> Collector<T, ?, R> filtering(Predicate<? super T> predicate, Collector<? super T, A, R> downstream); // since 9

    public static <T> Collector<T, ?, List<T>> toUnmodifiableList(); // since 10
    public static <T> Collector<T, ?, Set<T>> toUnmodifiableSet(); // since 10
    public static <T, K, U> Collector<T, ?, Map<K,U>> toUnmodifiableMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends U> valueMapper); // since 10
    public static <T, K, U> Collector<T, ?, Map<K,U>> toUnmodifiableMap(Function<? super T, ? extends K> keyMapper, Function<? super T, ? extends U> valueMapper, BinaryOperator<U> mergeFunction); // since 10
}

Lists the changes introduced to java.nio.file package in Java 8

jbang whats-new-in-java@grumpyf0x48 --source-path /usr/lib/jvm/openjdk-11 --release 1.8 java.nio.file.*

public final class Files // since 1.7
{
    public static BufferedReader newBufferedReader(Path path) throws IOException; // since 1.8
    public static BufferedWriter newBufferedWriter(Path path, OpenOption... options) throws IOException; // since 1.8
    public static List<String> readAllLines(Path path) throws IOException; // since 1.8
    public static Path write(Path path, Iterable<? extends CharSequence> lines, OpenOption... options) throws IOException; // since 1.8
    public static Stream<String> lines(Path path) throws IOException; // since 1.8
}

public final class FileTime // since 1.7
{
    public static FileTime from(Instant instant); // since 1.8
    public Instant toInstant(); // since 1.8
}

Lists the changes made to java.lang.Process in Java 9

jbang whats-new-in-java@grumpyf0x48 --source-path /usr/lib/jvm/openjdk-11 --show-abstract-classes --release 9 java.lang.Process java.lang.ProcessHandle

public interface ProcessHandle extends Comparable<ProcessHandle> // since 9
{
    public interface Info; // since 9
}

public abstract class Process
{
    public boolean supportsNormalTermination(); // since 9
    public long pid(); // since 9
    public CompletableFuture<Process> onExit(); // since 9
    public ProcessHandle toHandle(); // since 9
    public ProcessHandle.Info info(); // since 9
    public Stream<ProcessHandle> children(); // since 9
    public Stream<ProcessHandle> descendants(); // since 9
}

Lists the classes having changed in Java 9 in the java.time package

jbang whats-new-in-java@grumpyf0x48 --source-path /usr/lib/jvm/openjdk-11 --only-class-names --release 9 java.time.*

public final class OffsetTime // since 1.8
public final class LocalDate // since 1.8
public final class LocalTime // since 1.8
public final class DateTimeFormatterBuilder // since 1.8
public final class Duration // since 1.8
public interface Chronology extends Comparable<Chronology> // since 1.8
public final class IsoChronology extends AbstractChronology implements Serializable // since 1.8

List the changes made in Java 11 for strings

jbang whats-new-in-java@grumpyf0x48 --source-path /usr/lib/jvm/openjdk-11 --release 11 java.lang.String.*

public final class String
{
    public String strip(); // since 11
    public String stripLeading(); // since 11
    public String stripTrailing(); // since 11
    public boolean isBlank(); // since 11
    public Stream<String> lines(); // since 11
    public String repeat(int count); // since 11
}

public final class StringBuilder
{
    public int compareTo(StringBuilder another); // since 11
}

public final class StringBuffer
{
    public synchronized int compareTo(StringBuffer another); // since 11
}

List the java.lang.Integer java.lang.Long ... methods made deprecated in Java 9

jbang whats-new-in-java@grumpyf0x48 -d -r 9 java.lang.Integer java.lang.Long java.lang.Double

public final class Long extends Number implements Comparable<Long> // since 1.0
{
    public Long(long value); // @Deprecated(since="9")
    public Long(String s) throws NumberFormatException; // @Deprecated(since="9")
}

public final class Double extends Number implements Comparable<Double> // since 1.0
{
    public Double(double value); // @Deprecated(since="9")
    public Double(String s) throws NumberFormatException; // @Deprecated(since="9")
}

public final class Integer extends Number implements Comparable<Integer> // since 1.0
{
    public Integer(int value); // @Deprecated(since="9")
    public Integer(String s) throws NumberFormatException; // @Deprecated(since="9")
}

List the deprecated methods in package java.util.concurrent.atomic

jbang whats-new-in-java@grumpyf0x48 -d -r ALL java.util.concurrent.atomic.*

public class AtomicLong extends Number implements java.io.Serializable // since 1.5
{
    public final boolean weakCompareAndSet(long expectedValue, long newValue); // @Deprecated(since="9")
}

public class AtomicInteger extends Number implements java.io.Serializable // since 1.5
{
    public final boolean weakCompareAndSet(int expectedValue, int newValue); // @Deprecated(since="9")
}

...

public class AtomicIntegerArray implements java.io.Serializable // since 1.5
{
    public final boolean weakCompareAndSet(int i, int expectedValue, int newValue); // @Deprecated(since="9")
}

public class AtomicLongArray implements java.io.Serializable // since 1.5
{
    public final boolean weakCompareAndSet(int i, long expectedValue, long newValue); // @Deprecated(since="9")
}

List the deprecated methods of java.lang.Thread

jbang whats-new-in-java@grumpyf0x48 -d -r ALL java.lang.Thread

public class Thread implements Runnable // since 1.0
{
    public final void stop(); // @Deprecated(since="1.2")
    public final void suspend(); // @Deprecated(since="1.2")
    public final void resume(); // @Deprecated(since="1.2")
    public native int countStackFrames();  /** * Waits at most @code millis} milliseconds for this thread to; // @Deprecated(since="1.2", forRemoval=true)
}

Vote

A program to compute the result of a weighted vote.

See Décider avec le vote pondéré par capital de points.

It makes use of Java Stream filter, map, reduce (and collect) pattern, shows Stream.chars(), Stream.iterate(...) and Map sorting usage.

Vote test script validates Vote's output, can be run in IDEA and terminal and uses Java 15 text blocks.

Written with JBang, Picocli.

Sample use

With an input file containing the following pondered votes (First option has value 4, then 3, then 2 and finally 1):

cat vote.txt

H N T B
T N H B
N B T H
B T N H

and with vote options being: H, N, T and B:

jbang vote@grumpyf0x48 HNTB -f vote.txt

or:

cat vote.txt | jbang vote@grumpyf0x48 HNTB

The program output is:

H=4 N=3 T=2 B=1
T=4 N=3 H=2 B=1
N=4 B=3 T=2 H=1
B=4 T=3 N=2 H=1

N=12 T=11 B=9 H=8

So the winner is N with 12 points.

StatusCode

A sample sort program to illustrate Java 11 HttpClient use.

Written with JBang, Picocli and HttpClient.

jbang statusCode@grumpyf0x48 --help

Usage: StatusCode [-hV] <url>
StatusCode made with JBang and Java 11 HttpClient
      <url>       source URL
  -h, --help      Show this help message and exit.
  -V, --version   Print version information and exit.

Sample use

jbang statusCode@grumpyf0x48 https://framagit.org
200

CLI Templates

A CLI template to write a Picocli-based command with default JAVA, JAVA_OPTIONS and JAVAC_OPTIONS set:

jbang init --template=cli@grumpyf0x48 -DJAVA=18 MyCommandLine.java

Test templates

Each template contains a main method so that the generated test script can be run directly with JBang. It then runs all tests it defines.

The main method uses a summary method that helps in printing test results. The user is free to change this if it does not suit his needs.

When some tests are failing, the script returns exit code 1, otherwise it returns 0.

JUnit 4 template

A template to generate a basic JUnit 4 test script for a JBang script.

To generate a JUnit 4 test class named ScriptTest for a JBang script named Script.java:

jbang init -DscriptName=Script --template=junit4@grumpyf0x48 ScriptTest.java

The generated script looks like the following:

Then, after adding tests to ScriptTest.java, run it with:

./ScriptTest.java

JUnit 5 template

A template to generate a basic JUnit 5 test script for a JBang script.

To generate a JUnit 5 test class named ScriptTest for a JBang script named Script.java:

jbang init -DscriptName=Script --template=junit5@grumpyf0x48 ScriptTest.java

TestNG template

A template to generate a basic TestNG test script for a JBang script.

To generate a TestNG test class named ScriptTest for a JBang script named Script.java:

jbang init -DscriptName=Script --template=testng@grumpyf0x48 ScriptTest.java