What are the different startup scripts in JShell in Java 9?

JShell is an interactive Java Shell tool that can execute code from JShell and display the output immediately. JShell is a REPL (Read-Evaluate-Print-Loop) tool that can be run from the command line prompt.

In JShell, there is an option to load a script on startup that contains some special predefined options. These options can be specified using the "--startup" flag, passing in a filename or one of DEFAULT, JAVASE, and PRINTING. We can use the "/list -start" command to view all startup code snippets to be evaluated.

• DEFAULT: It loads the default behavior. This is the same as not specifying it at all.
• JAVASE: Imports all Java SE packages by default.
• PRINTING: Define the functions print, println and printf for printing.

In the following code snippet, we can use "DEFAULT" as the startup script.

C:\Users\User>jshell --startup DEFAULT
| Welcome to JShell -- Version 9.0.4
| For an introduction type: /help intro

jshell> /list -start

s1 : import java.io.*;
s2 : import java.math.*;
s3 : import java.net.*;
s4 : import java.nio.file.*;
s5 : import java.util.*;
s6 : import java.util.concurrent.*;
s7 : import java.util.function.*;
s8 : import java.util.prefs.*;
s9 : import java.util.regex.*;
s10 : import java.util.stream.*;

In the following code snippet, we can use "JAVASE" as a startup script.

C:\Users\User>jshell --startup JAVASE
| Welcome to JShell -- Version 9.0.4
| For an introduction type: /help intro

jshell> /list -start

s1 : import java.applet.*;
s2 : import java.awt.*;
s3 : import java.awt.color.*;
s4 : import java.awt.datatransfer.*;
s5 : import java.awt.desktop.*;
s6 : import java.awt.dnd.*;
s7 : import java.awt.event.*;
s8 : import java.awt.font.*;
s9 : import java.awt.geom.*;
s10 : import java.awt.im.*;
s11 : import java.awt.im.spi.*;
s12 : import java.awt.image.*;
s13 : import java.awt.image.renderable.*;
s14 : import java.awt.print.*;
s15 : import java.beans.*;
s16 : import java.beans.beancontext.*;
s17 : import java.io.*;
s18 : import java.lang.*;
s19 : import java.lang.annotation.*;
s20 : import java.lang.instrument.*;
s21 : import java.lang.invoke.*;
s22 : import java.lang.management.*;
s23 : import java.lang.module.*;
s24 : import java.lang.ref.*;
s25 : import java.lang.reflect.*;
s26 : import java.math.*;
s27 : import java.net.*;
s28 : import java.net.spi.*;
s29 : import java.nio.*;
s30 : import java.nio.channels.*;
s31 : import java.nio.channels.spi.*;
s32 : import java.nio.charset.*;
s33 : import java.nio.charset.spi.*;
s34 : import java.nio.file.*;
s35 : import java.nio.file.attribute.*;
s36 : import java.nio.file.spi.*;
s37 : import java.rmi.*;
s38 : import java.rmi.activation.*;
s39 : import java.rmi.dgc.*;
s40 : import java.rmi.registry.*;
s41 : import java.rmi.server.*;
s42 : import java.security.*;
s43 : import java.security.acl.*;
s44 : import java.security.cert.*;
s45 : import java.security.interfaces.*;
s46 : import java.security.spec.*;
s47 : import java.sql.*;
s48 : import java.text.*;
s49 : import java.text.spi.*;
s50 : import java.time.*;
s51 : import java.time.chrono.*;
s52 : import java.time.format.*;
s53 : import java.time.temporal.*;
s54 : import java.time.zone.*;
s55 : import java.util.*;
s56 : import java.util.concurrent.*;
s57 : import java.util.concurrent.atomic.*;
s58 : import java.util.concurrent.locks.*;
s59 : import java.util.function.*;
s60 : import java.util.jar.*;
s61 : import java.util.logging.*;
s62 : import java.util.prefs.*;
s63 : import java.util.regex.*;
s64 : import java.util.spi.*;
s65 : import java.util.stream.*;
s66 : import java.util.zip.*;
s67 : import javax.accessibility.*;
s68 : import javax.annotation.processing.*;
s69 : import javax.crypto.*;
s70 : import javax.crypto.interfaces.*;
s71 : import javax.crypto.spec.*;
s72 : import javax.imageio.*;
s73 : import javax.imageio.event.*;
s74 : import javax.imageio.metadata.*;
s75 : import javax.imageio.plugins.bmp.*;
s76 : import javax.imageio.plugins.jpeg.*;
s77 : import javax.imageio.plugins.tiff.*;
s78 : import javax.imageio.spi.*;
s79 : import javax.imageio.stream.*;
s80 : import javax.lang.model.*;
s81 : import javax.lang.model.element.*;
s82 : import javax.lang.model.type.*;
s83 : import javax.lang.model.util.*;
s84 : import javax.management.*;
s85 : import javax.management.loading.*;
s86 : import javax.management.modelmbean.*;
s87 : import javax.management.monitor.*;
s88 : import javax.management.openmbean.*;
s89 : import javax.management.relation.*;
s90 : import javax.management.remote.*;
s91 : import javax.management.remote.rmi.*;
s92 : import javax.management.timer.*;
s93 : import javax.naming.*;
s94 : import javax.naming.directory.*;
s95 : import javax.naming.event.*;
s96 : import javax.naming.ldap.*;
s97 : import javax.naming.spi.*;
s98 : import javax.net.*;
s99 : import javax.net.ssl.*;
s100 : import javax.print.*;
s101 : import javax.print.attribute.*;
s102 : import javax.print.attribute.standard.*
s103 : import javax.print.event.*;
s104 : import javax.rmi.ssl.*;
s105 : import javax.script.*;
s106 : import javax.security.auth.*;
s107 : import javax.security.auth.callback.*;
s108 : import javax.security.auth.kerberos.*;
s109 : import javax.security.auth.login.*;
s110 : import javax.security.auth.spi.*;
s111 : import javax.security.auth.x500.*;
s112 : import javax.security.cert.*;
s113 : import javax.security.sasl.*;
s114 : import javax.sound.midi.*;
s115 : import javax.sound.midi.spi.*;
s116 : import javax.sound.sampled.*;
s117 : import javax.sound.sampled.spi.*;
s118 : import javax.sql.*;
s119 : import javax.sql.rowset.*;
s120 : import javax.sql.rowset.serial.*;
s121 : import javax.sql.rowset.spi.*;
s122 : import javax.swing.*;
s123 : import javax.swing.border.*;
s124 : import javax.swing.colorchooser.*;
s125 : import javax.swing.event.*;
s126 : import javax.swing.filechooser.*;
s127 : import javax.swing.plaf.*;
s128 : import javax.swing.plaf.basic.*;
s129 : import javax.swing.plaf.metal.*;
s130 : import javax.swing.plaf.multi.*;
s131 : import javax.swing.plaf.nimbus.*;
s132 : import javax.swing.plaf.synth.*;
s133 : import javax.swing.table.*;
s134 : import javax.swing.text.*;
s135 : import javax.swing.text.html.*;
s136 : import javax.swing.text.html.parser.*;
s137 : import javax.swing.text.rtf.*;
s138 : import javax.swing.tree.*;
s139 : import javax.swing.undo.*;
s140 : import javax.tools.*;
s141 : import javax.transaction.xa.*;
s142 : import javax.xml.*;
s143 : import javax.xml.catalog.*;
s144 : import javax.xml.crypto.*;
s145 : import javax.xml.crypto.dom.*;
s146 : import javax.xml.crypto.dsig.*;
s147 : import javax.xml.crypto.dsig.dom.*;
s148 : import javax.xml.crypto.dsig.keyinfo.*;
s149 : import javax.xml.crypto.dsig.spec.*;
s150 : import javax.xml.datatype.*;
s151 : import javax.xml.namespace.*;
s152 : import javax.xml.parsers.*;
s153 : import javax.xml.stream.*;
s154 : import javax.xml.stream.events.*;
s155 : import javax.xml.stream.util.*;
s156 : import javax.xml.transform.*;
s157 : import javax.xml.transform.dom.*;
s158 : import javax.xml.transform.sax.*;
s159 : import javax.xml.transform.stax.*;
s160 : import javax.xml.transform.stream.*;
s161 : import javax.xml.validation.*;
s162 : import javax.xml.xpath.*;
s163 : import org.ietf.jgss.*;
s164 : import org.w3c.dom.*;
s165 : import org.w3c.dom.bootstrap.*;
s166 : import org.w3c.dom.events.*;
s167 : import org.w3c.dom.ls.*;
s168 : import org.w3c.dom.ranges.*;
s169 : import org.w3c.dom.traversal.*;
s170 : import org.w3c.dom.views.*;
s171 : import org.xml.sax.*;
s172 : import org.xml.sax.ext.*;
s173 : import org.xml.sax.helpers.*;

In the following code snippet, we can use "PRINTING" as the startup script.

C:\Users\User>jshell --startup PRINTING
| Welcome to JShell -- Version 9.0.4
| For an introduction type: /help intro

jshell> /list -start

s1 : void print(boolean b) { System.out.print(b); }
s2 : void print(char c) { System.out.print(c); }
s3 : void print(int i) { System.out.print(i); }
s4 : void print(long l) { System.out.print(l); }
s5 : void print(float f) { System.out.print(f); }
s6 : void print(double d) { System.out.print(d); }
s7 : void print(char s[]) { System.out.print(s); }
s8 : void print(String s) { System.out.print(s); }
s9 : void print(Object obj) { System.out.print(obj); }
s10 : void println() { System.out.println(); }
s11 : void println(boolean b) { System.out.println(b); }
s12 : void println(char c) { System.out.println(c); }
s13 : void println(int i) { System.out.println(i); }
s14 : void println(long l) { System.out.println(l); }
s15 : void println(float f) { System.out.println(f); }
s16 : void println(double d) { System.out.println(d); }
s17 : void println(char s[]) { System.out.println(s); }
s18 : void println(String s) { System.out.println(s); }
s19 : void println(Object obj) { System.out.println(obj); }
s20 : void printf(java.util.Locale l, String format, Object... args) { System.out.printf(l, format, args); }
s21 : void printf(String format, Object... args) { System.out.printf(format, args); }

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