Initial commit

.gitattributes

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+# Auto detect text files and perform LF normalization
+* text=auto

.gitignore

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+nbproject/private/**
+nbproject/Makefile-*.mk
+nbproject/Package-*.bash
+.nb-gradle/
+
+build/
+dist/
+
+# Compiled class file
+*.class
+
+# Log file
+*.log
+
+# virtual machine crash logs
+hs_err_pid*
+

LICENSE

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+BSD 2-Clause License
+
+Copyright (c) 2018, Christopher G. Jennings
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

MANIFEST.MF

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+Manifest-Version: 1.0
+Ant-Version: Apache Ant 1.10.4
+Created-By: 11.0.2+9-LTS (Oracle Corporation)
+Premain-Class: ca.cgjennings.jvm.JarLoader
+Agent-Class: ca.cgjennings.jvm.JarLoader
+

README.md

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+# Jar Loader
+
+![jar loader icon](readme/images/coffee-jar.png)
+
+## What is it?
+
+Easy migration to Java 9+ for applications that extend the class path by reflective access to the class loader.
+
+Does your code work under Java 8 but fail under Java 9+ with an error stating that the system class loader is not an instance of `URLClassLoader` or that the method `addURL` could not be found? *Then this is for you.*
+
+## How to use it
+
+Three steps:
+
+1. Add `jar-loader.jar` to your build libraries and application class path.
+2. Add `-javaagent:path/to/jar-loader.jar` to the VM options passed to the `java` command used to start your application.
+3. Where your code previously used reflection to invoke `addURL` on the system class loader, instead call `ca.cgjennings.jvm.JarLoader.addToClassPath(File jarFile)`.
+
+### Notes
+
+*Jar Loader* uses an official, documented method for extending the class path at runtime that has been supported since Java 6. It falls back to attempting reflective access if that fails. This method differs from `URLClassLoader` in that it only supports local JAR files. If your code relies on `addURL` to download code over a network, you will have to download it yourself and write it to a local file.
+
+If you move the compiled `JarLoader` class to a different JAR file, it must include a `MANIFEST.MF` with the following line:
+
+`Premain-Class: ca.cgjennings.vm.JarLoader`
+
+
+
+---
+
+**Image credit:** icon adapted from an icon by [Eucalyp](https://www.flaticon.com/authors/eucalyp).

build.xml

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+<?xml version="1.0" encoding="UTF-8"?>
+<!-- You may freely edit this file. See commented blocks below for -->
+<!-- some examples of how to customize the build. -->
+<!-- (If you delete it and reopen the project it will be recreated.) -->
+<!-- By default, only the Clean and Build commands use this build script. -->
+<!-- Commands such as Run, Debug, and Test only use this build script if -->
+<!-- the Compile on Save feature is turned off for the project. -->
+<!-- You can turn off the Compile on Save (or Deploy on Save) setting -->
+<!-- in the project's Project Properties dialog box.-->
+<project name="jar-loader" default="default" basedir=".">
+    <description>Builds, tests, and runs the project jar-loader.</description>
+    <import file="nbproject/build-impl.xml"/>
+
+   <manifest file="MANIFEST.MF">
+      <attribute name="Premain-Class" value="ca.cgjennings.jvm.JarLoader" />
+      <attribute name="Agent-Class" value="ca.cgjennings.jvm.JarLoader" />
+   </manifest>    
+
+    <!--
+
+    There exist several targets which are by default empty and which can be 
+    used for execution of your tasks. These targets are usually executed 
+    before and after some main targets. They are: 
+
+      -pre-init:                 called before initialization of project properties
+      -post-init:                called after initialization of project properties
+      -pre-compile:              called before javac compilation
+      -post-compile:             called after javac compilation
+      -pre-compile-single:       called before javac compilation of single file
+      -post-compile-single:      called after javac compilation of single file
+      -pre-compile-test:         called before javac compilation of JUnit tests
+      -post-compile-test:        called after javac compilation of JUnit tests
+      -pre-compile-test-single:  called before javac compilation of single JUnit test
+      -post-compile-test-single: called after javac compilation of single JUunit test
+      -pre-jar:                  called before JAR building
+      -post-jar:                 called after JAR building
+      -post-clean:               called after cleaning build products
+
+    (Targets beginning with '-' are not intended to be called on their own.)
+
+    Example of inserting an obfuscator after compilation could look like this:
+
+        <target name="-post-compile">
+            <obfuscate>
+                <fileset dir="${build.classes.dir}"/>
+            </obfuscate>
+        </target>
+
+    For list of available properties check the imported 
+    nbproject/build-impl.xml file. 
+
+
+    Another way to customize the build is by overriding existing main targets.
+    The targets of interest are: 
+
+      -init-macrodef-javac:     defines macro for javac compilation
+      -init-macrodef-junit:     defines macro for junit execution
+      -init-macrodef-debug:     defines macro for class debugging
+      -init-macrodef-java:      defines macro for class execution
+      -do-jar:                  JAR building
+      run:                      execution of project 
+      -javadoc-build:           Javadoc generation
+      test-report:              JUnit report generation
+
+    An example of overriding the target for project execution could look like this:
+
+        <target name="run" depends="jar-loader-impl.jar">
+            <exec dir="bin" executable="launcher.exe">
+                <arg file="${dist.jar}"/>
+            </exec>
+        </target>
+
+    Notice that the overridden target depends on the jar target and not only on 
+    the compile target as the regular run target does. Again, for a list of available 
+    properties which you can use, check the target you are overriding in the
+    nbproject/build-impl.xml file. 
+
+    -->
+</project>