I have a groovy script and i want to execute it in java. Could someone provide me with further documentation / examples on how this is possible?
Basic Java+Groovy Integration:
// call groovy expressions from Java code
Binding binding = new Binding();
binding.setVariable("foo", new Integer(2));
GroovyShell shell = new GroovyShell(binding);
Object value = shell.evaluate(groovyScript);
See this article for more ways to call Groovy from Java
PS: You need to include groovy-all-m.n.m.jar e.g. groovy-all-2.1.6.jar in your Java program, for example:
<dependency>
<groupId>org.codehaus.groovy</groupId>
<artifactId>groovy-all</artifactId>
<version>2.4.8</version>
</dependency>
Related
I'm trying to use Byte Buddy library in Android but I get an error:
java.lang.IllegalStateException: This JVM's version string does not
seem to be valid: 0
I have coded nothing yet, just:
ByteBuddy test = new ByteBuddy();
in my App.java
I have imported:
<dependency>
<groupId>net.bytebuddy</groupId>
<artifactId>byte-buddy</artifactId>
<version>0.7.7</version>
</dependency>
but it didn't work, to I tried with:
<dependency>
<groupId>net.bytebuddy</groupId>
<artifactId>byte-buddy-android</artifactId>
<version>0.7.7</version>
</dependency>
but I still get same error.
EDIT
I have put this line before initialize ByteBuddy:
System.setProperty("java.version", "1.7.0_51");
But now I get this another error:
Caused by: java.lang.UnsupportedOperationException: can't load this
type of class file.
for this code:
Class<?> dynamicType = new ByteBuddy(ClassFileVersion.JAVA_V6)
.subclass(Object.class)
.method(ElementMatchers.named("toString"))
.intercept(FixedValue.value("Hello World!"))
.make()
.load(getClass().getClassLoader(), AndroidClassLoadingStrategy.Default.WRAPPER)
.getLoaded();
The error is because java.version returns 0 in Android (See section System Properties here - Comparison of Java and Android API)
Also, if you observe ByteBuddy ClassFileVersion
forCurrentJavaVersion() : This method checks for versionString which should return any valid Java/JDK version else it
throws IllegalStateException("This JVM's version string does not seem to be valid: " + versionString);
& since java.version is returning 0, it's throwing IllegalStateException.
Try to log this value:
String versionString = System.getProperty(JAVA_VERSION_PROPERTY);
Log.d(TAG, versionString);//retruns 0 here
hence workaround for this issue is to add
System.setProperty(JAVA_VERSION_PROPERTY, "1.7.0_79");//add your jdk version here
before calling
ByteBuddy test = new ByteBuddy();
where JAVA_VERSION_PROPERTY is declared as:
private static final String JAVA_VERSION_PROPERTY = "java.version";
Also dependency to use is:
<dependency>
<groupId>net.bytebuddy</groupId>
<artifactId>byte-buddy</artifactId>
<version>0.7.7</version>
</dependency>
Else if you are using studio, you can add
compile 'net.bytebuddy:byte-buddy:0.7.7'
to your app build.gradle.
Hope this will help solve your issue.
Using Java 8, I'd like to programmatically load a javascript file and execute it using Avatar JS (for Node env support). I also want to use Maven to manage the dependencies.
Here's the simple Nashorn snippet I'm using and I'd like to extend this to support Node.JS modules, ideally using Avatar JS.
ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
InputStream in = getClass().getClassLoader().getResourceAsStream("js/hello-world.js");
String result = (String)engine.eval(new InputStreamReader(in));
System.out.print(result);
The relevant Maven config also looks like this:
<repositories>
<repository>
<id>nexus-snapshots</id>
<name>Nexus Snapshots</name>
<url>https://maven.java.net/content/repositories/snapshots/</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>com.oracle</groupId>
<artifactId>avatar-js</artifactId>
<version>0.10.32-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>com.oracle</groupId>
<artifactId>libavatar-js-linux-x64</artifactId>
<version>0.10.32-SNAPSHOT</version>
<type>pom</type>
</dependency>
</dependencies>
I get the impression there's a lot of good functionality in Avatar, but I'm struggling to find any decent docs or examples. Can anyone provide a code example of how to do this?
I figured this out, the relevant code I have running looks like this:
import com.oracle.avatar.js.Server;
import com.oracle.avatar.js.Loader;
import com.oracle.avatar.js.log.Logging;
and
String runJs() throws Throwable {
StringWriter scriptWriter = new StringWriter();
ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn");
ScriptContext scriptContext = engine.getContext();
scriptContext.setWriter(scriptWriter);
Server server = new Server(engine, new Loader.Core(), new Logging(false), System.getProperty("user.dir"));
server.run("js/hello-world.js");
return scriptWriter.toString();
}
and, for now, a simple hello-world.js:
var util = require('util')
var result = util.format('hello %s', 'Phil');
print(result);
I also pass in java.library.home as a JVM argument when running the application. The Avatar native library resides in this directory
I am trying to use an open source tool built on Batik and I am running into trouble with one of the dependencies when I try to build it. Pretty sure this is something to do with classpaths and library locations, but I can't figure out what is happening.
So the project I am working with ( SVG2EMF ) is using the FreeHep EMF Driver, which in turn uses the FreeHep GraphicsIO project. Because these three have not been playing nicely on my system ( Ubuntu 14.04 ) I've downloaded the source for all three to try and step through the problem.
Everything builds correctly and I can step through the code successfully, but the unit tests on SVG2EMF fail at the point where the EMF Driver makes a call to something from GraphicsIO- the relevant parts of the code in question is here:
import org.freehep.graphicsio.ImageGraphics2D;
import org.freehep.graphicsio.ImageConstants;
// ...snip...
public class AlphaBlend extends EMFTag implements EMFConstants
{
// ...snip...
public void write(int tagID, EMFOutputStream emf) throws IOException
{
emf.writeRECTL(bounds);
emf.writeLONG(x);
emf.writeLONG(y);
emf.writeLONG(width);
emf.writeLONG(height);
dwROP.write(emf);
emf.writeLONG(xSrc);
emf.writeLONG(ySrc);
emf.writeXFORM(transform);
emf.writeCOLORREF(bkg);
emf.writeDWORD(usage);
emf.writeDWORD(size); // bmi follows this record immediately
emf.writeDWORD(BitmapInfoHeader.size);
emf.writeDWORD(size + BitmapInfoHeader.size); // bitmap follows bmi
emf.pushBuffer();
int encode;
// plain
encode = BI_RGB;
ImageGraphics2D.writeImage(
(RenderedImage) image,
ImageConstants.RAW.toLowerCase(),
ImageGraphics2D.getRAWProperties(bkg, "*BGRA"),
new NoCloseOutputStream(emf));
// emf.writeImage(image, bkg, "*BGRA", 1);
// png
// encode = BI_PNG;
// ImageGraphics2D.writeImage(image, "png", new Properties(), new
// NoCloseOutputStream(emf));
// jpg
// encode = BI_JPEG;
// ImageGraphics2D.writeImage(image, "jpg", new Properties(), new
// NoCloseOutputStream(emf));
int length = emf.popBuffer();
emf.writeDWORD(length);
emf.writeLONG(image.getWidth());
emf.writeLONG(image.getHeight());
BitmapInfoHeader header = new BitmapInfoHeader(image.getWidth(), image
.getHeight(), 32, encode, length, 0, 0, 0, 0);
bmi = new BitmapInfo(header);
bmi.write(emf);
emf.append();
}
This throws a NoClassDefFoundError specifically relating to org.freehep.graphicsio.ImageGraphics2D on that writeImage call. When I step through in the debugger, a watch on ImageConstants.RAW has the value of Unknown type "org.freehep.graphicsio.ImageConstants" even though the application built quite happily with those references. Any references to ImageGraphics2D behave in exactly the same way.
The dependency in the SVG2EMF pom.xml looks like this:
<dependencies>
<!-- some other dependencies -->
<dependency>
<groupId>org.freehep</groupId>
<artifactId>freehep-graphicsio-emf</artifactId>
<version>2.1.1</version>
</dependency>
</dependencies>
Dependency from the FreeHEP EMF Driver looks like this:
<dependencies>
<!-- necessary because transitive deps seem to go above inhertied deps -->
<dependency>
<groupId>org.freehep</groupId>
<artifactId>freehep-util</artifactId>
<version>2.0.2</version>
</dependency>
<dependency>
<groupId>org.freehep</groupId>
<artifactId>freehep-graphicsio</artifactId>
<version>2.1.1</version>
</dependency>
<!-- Other dependencies -->
</dependencies>
Can anybody shed any light on what is actually going on here or what I need to be doing in order to enable this to work?
EDIT: I think I have found where the problem is coming from- way down the StackTrace I see a "Caused by: ExceptionInInitializerError" - which appears to mark the class as inaccessible from then on. So the dependency does exist, but an exception is being thrown by the initializer which causes the JRE to mark it as unusable.
Further Edit: To solve these problems it can be useful ( although it is not mentioned anywhere on the freehep.org website ) to know that the project is now hosted on Github so you can find newer versions from there. In my case going straight to the latest version solved the problem.
I'm building a Python UI using Tkinter. For the needs of the program, I've to connect Python with Java to do some stuff, so I'm using a simple Jython script as a linker. I cant use Tkinter with Jython because it's not supported.
Python (ui.py) -> Jython (linker.py) -> Java (compiled in jars)
To call the Jython function in Python I use subprocess as follows:
ui.py:
cmd = 'jython linker.py"'
my_env = os.environ
my_env["JYTHONPATH"] = tons_of_jars
subprocess.Popen(cmd, shell=True, env=my_env)
Then, in the Jython file, linker.py, I import the Java classes already added on the JYTHONPATH, and I create an object with the name m and call to some functions of the Java class.
linker.py:
import handler.handler
m = handler.handler(foo, moo, bar)
m.schedule(moo)
m.getFullCalendar()
m.printgantt()
The thing is that I've created a m object, that will be destroyed after the execution of jython linker.py ends.
So the question is: Is possible to save that m object somewhere so I can call it from ui.py whenever I want? If it's not possible, is there any other way to do this?
Thanks in advance.
I finally solved it by using ObjectOutputStream.
from java import io
def saveObject(x, fname="object.bin"):
outs = io.ObjectOutputStream(io.FileOutputStream(fname))
outs.writeObject(x)
outs.close()
def loadObject(fname="object.bin"):
ins = io.ObjectInputStream(io.FileInputStream(fname))
x=ins.readObject()
ins.close()
return x
I inherited some code that is using XPath for which I am a novice. I have it now so that it loads the document, but when the document.selectPath(queryPath) it always fails with the following error:
java.lang.RuntimeException: Trying XBeans path engine... Trying XQRL... Trying delegated path engine... FAILED on //
at org.apache.xmlbeans.impl.store.Path.getCompiledPath(Path.java:173)
at org.apache.xmlbeans.impl.store.Path.getCompiledPath(Path.java:130)
at org.apache.xmlbeans.impl.store.Cursor._selectPath(Cursor.java:902)
at org.apache.xmlbeans.impl.store.Cursor.selectPath(Cursor.java:2634)
at org.apache.xmlbeans.impl.values.XmlObjectBase.selectPath(XmlObjectBase.java:462)
at org.apache.xmlbeans.impl.values.XmlObjectBase.selectPath(XmlObjectBase.java:446)
Thank you jor for the post. I was confused as earlier commands to xml beans were successful.
Without saxon, this still works:
MapDocument doc;
...
String cityQuery = "$this//City";
XmlObject[] cities = doc.selectPath(cityQuery);
However saxon is required for explicit selection of fields within tags:
String aveQuery= "$this//Street[Kind='Avenue']";
XmlObject[] avenues = doc.selectPath(aveQuery); // RuntimeException without saxon on path
java.lang.RuntimeException:
Trying XBeans path engine... Trying XQRL... Trying delegated path engine... FAILED on $this//Street[Kind='Avenue']
I hope this might be of use to others that encounter a similar issue.
You need an XPath engine in your classpath, which one bepends on the XMLBeans version, see
http://wiki.apache.org/xmlbeans/XmlBeansFaq#whatJars
The movement if you have [] in your xpath, it is searching for the external xpath enginer.. you have to download saxonb9-0-0-4j & xmlbeans-xpath-2.4.0.jar and add to the classpath
worked for me:
<dependency>
<groupId>org.apache.xmlbeans</groupId>
<artifactId>xmlbeans</artifactId>
<version>4.0.0</version>
</dependency>
<dependency>
<groupId>net.sf.saxon</groupId>
<artifactId>Saxon-HE</artifactId>
<version>10.6</version>
</dependency>
<dependency>
<groupId>org.dom4j</groupId>
<artifactId>dom4j</artifactId>
<version>2.1.3</version>
</dependency>