PDE running under linux but sketches fail on java path.

As part of processing#5753 and processing#5750, working AdoptOpenJDK released java on
Elementary Linux 5.0 (Juno, 64bit). Linux 4.15.0-36-generic. Tested
with Java 11. JDK downloads working and PDE runs but sketches wont
execute due to broken java path.

build/build.xml

@@ -73,7 +73,7 @@
   <property name="jdk.train" value="11" />
   <property name="jdk.version" value="0" />
   <property name="jdk.update" value="1" />
-  <property name="jdk.build" value="12" />
+  <property name="jdk.build" value="13" />
   <!-- See https://gist.github.com/P7h/9741922
        or http://stackoverflow.com/q/10268583 -->
   <property name="jdk.hash" value="750e1c8617c5452694857ad95c3ee230" />
@@ -234,7 +234,7 @@
   <target name="jre-download" depends="jre-check, downloader-setup"
           unless="jre.tgz.downloaded">
     <!-- we normally download a JRE, except on arm -->
-    <property name="jre.download.jdk" value="false" />
+    <property name="jre.download.jdk" value="true" />
 
     <condition property="jre.downloader"
                value="${platform}-i586.tar.gz">
@@ -245,7 +245,10 @@
       <equals arg1="${sun.arch.data.model}" arg2="64" />
     </condition>
 
-    <downloader version="${jdk.version}"
+    <downloader train="${jdk.train}"
+                version="${jdk.version}"
+                openJdk="true"
+                platform="linux64"
                 update="${jdk.update}"
                 build="${jdk.build}"
                 hash="${jdk.hash}"
@@ -877,20 +880,35 @@
     </exec>
 
     <!-- use the jre subfolder when having downloaded a JDK file -->
-    <condition property="jre.dir" value="jdk${jdk.esoteric}/jre">
+    <condition property="jre.dir" value="jdk${jdk.esoteric}">
       <!-- property might not be set, but it is for arm -->
-      <equals arg1="${jre.download.jdk}" arg2="true" />
+      <and>
+        <equals arg1="${jre.download.jdk}" arg2="true" />
+        <equals arg1="${jdk.train}" arg2="1" />
+      </and>
     </condition>
+
+    <!-- use top level JRE otherwise -->
     <condition property="jre.dir" value="jre${jdk.esoteric}">
+      <and>
+        <not>
+          <equals arg1="${jre.download.jdk}" arg2="true" />
+        </not>
+        <equals arg1="${jdk.train}" arg2="1" />
+      </and>
+    </condition>
+
+    <!-- Force full JDK when not on train 1 (force when on java 11) -->
+    <condition property="jre.dir" value="jdk-${jdk.esoteric}+${jdk.build}">
       <not>
-        <equals arg1="${jre.download.jdk}" arg2="true" />
+        <equals arg1="${jdk.train}" arg2="1" />
       </not>
     </condition>
 
     <exec executable="rsync" dir="linux">
       <arg value="-a" />
       <arg value="--delete" />
-      <arg value="${jre.dir}/" />
+      <arg value="${jre.dir}" />
       <arg value="work/java/" />
     </exec>
 

build/jre/src/Downloader.java

@@ -32,11 +32,11 @@ public class Downloader extends Task {
 
   public Downloader() { }
 
-  private void setPlatform(String platform) {
+  public void setPlatform(String platform) {
     this.platform = platform;
   }
 
-  private void setOpenJdk(boolean openJdk) {
+  public void setOpenJdk(boolean openJdk) {
     this.openJdk = openJdk;
   }
 
@@ -80,7 +80,12 @@ public void setPath(String path) {
 
 
   public void execute() throws BuildException {
-    if (version == 0) {
+    if (train == 0) {
+      throw new BuildException("Train (i.e. 1 or 11) must be set");
+    }
+
+    boolean isJava11 = train == 11;
+    if (!isJava11 && version == 0) {
       throw new BuildException("Version (i.e. 7 or 8) must be set");
     }
 
@@ -137,6 +142,8 @@ void download() throws IOException {
             hash
     );
 
+    System.out.println("Attempting download at " + url);
+
     HttpURLConnection conn =
       (HttpURLConnection) new URL(url).openConnection();
     conn.setRequestProperty("Cookie", COOKIE);

build/linux/processing

@@ -1,11 +1,11 @@
 #!/bin/sh
 
-# This script runs Processing, using the JRE in the Processing 
+# This script runs Processing, using the JRE in the Processing
 # installation directory.
 
 # If your system needs a different version of Java than what's included
 # in the download, replace the 'java' folder with the contents of a new
-# Oracle JRE (Java 8 only), or create a symlink named "java" in the 
+# Oracle JRE (Java 8 only), or create a symlink named "java" in the
 # Processing installation directory that points to the JRE home directory.
 # This must be a Sun/Oracle JDK. For more details, see here:
 # https://github.com/processing/processing/wiki/Supported-Platforms
@@ -104,7 +104,7 @@ cmd_name='processing-java'
 
 if [ $current_name = $cmd_name ]
 then
-    java -Djna.nosys=true -Djava.ext.dirs="$APPDIR"/java/lib/ext -Xmx256m processing.mode.java.Commander "$@"
+    java -Djna.nosys=true -Xmx256m processing.mode.java.Commander "$@"
     exit $?
 else
   # Start Processing in the same directory as this script
@@ -115,5 +115,5 @@ else
   fi
   cd "$APPDIR"
 
-  java -splash:lib/about-1x.png -Djna.nosys=true -Djava.ext.dirs="$APPDIR"/java/lib/ext -Xmx256m processing.app.Base "$SKETCH" &
+  java -splash:lib/about-1x.png -Djna.nosys=true -Xmx256m processing.app.Base "$SKETCH" &
 fi

java/src/processing/mode/java/runner/Runner.java

@@ -351,10 +351,10 @@ protected StringList getMachineParams() {
     }
     // sketch.libraryPath might be ""
     // librariesClassPath will always have sep char prepended
-    params.append("-Djava.library.path=" +
+    /*params.append("-Djava.library.path=" +
                   build.getJavaLibraryPath() +
                   File.pathSeparator +
-                  System.getProperty("java.library.path"));
+                  System.getProperty("java.library.path"));*/
 
     params.append("-cp");
     params.append(build.getClassPath());