I want to import a class that I made in my project, into my script
I did this but it doesn't work:
function doFunction(){
//Objectif Mensuel
importPackage(java.lang);
importClass(KPDataModel.KPData.KPItem); //ERROR HERE, this is my class that I want to import
KPItem kpItem = kpItemList.get(0);
System.out.println(kpItem.CellList.get(2).Value);
System.out.println("-------");
var proposedMediationSum = Integer.parseInt(kpItemList.get(0).CellList.get(2).Value);
var refusedMediationSum = Integer.parseInt(kpItemList.get(0).CellList.get(3).Value)
var totalMediation = proposedMediationSum + refusedMediationSum;
kpItemList.get(0).CellList.get(4).Value = totalMediation;
}
Well, thnx a lot, I found that the problem comes from the import.
This is what it said in the Oracle website :
The Packages global variable can be
used to access Java packages.
Examples: Packages.java.util.Vector,
Packages.javax.swing.JFrame. Please
note that "java" is a shortcut for
"Packages.java". There are equivalent
shortcuts for javax, org, edu, com,
net prefixes, so pratically all JDK
platform classes can be accessed
without the "Packages" prefix.
So, to import my class I used : importClass(Packages.KPDataModel.KPData.KPItem);
Related
In Java programming, we should firstly add weka.jar into our classpath, thus we can call all classify or cluster algorithms in WEKA in the form of the following codes,
import weka.classifiers.trees.RandomForest;
...
RandomForest rf = new RandomForest(); // RandomForest object
But unfortunately, we can not use this way to import LibSVM algorithm, because there is not such class in weka.jar.
So, my question is How to import LibSVM into my Java code? Any help will be grateful :)
Firstly, I'd like to say there are so many methods to solve the problem. The solution I mentioned is quite simple, but other answers from StackOverflow are not detailed descripted, with waste my too much time to verify. So I'm happy to share it with all WEKA beginners :)
a) Download the LibSVM.jar from Maven Repository Center. Note that this LibSVM.jar is different from the libsvm.jar developed by Chih-Chung Chang and Chih-Jen Lin;
b) Add the LibSVM.jar to the classpath of our Java project;
c) Call the classifier LibSVM when you need, see the following Java code.
import weka.classifiers.functions.LibSVM; // contained in LibSVM.jar
String path = "file/train.arff";
Instances train = DataSource.read(path); // load the dataset
train.setClassIndex(train.numAttribute()-1); // set class index
LibSVM svm = new LibSVM(); // load the svm classifier
svm.buildClassifier(train);
Evaluation eval = new Evaluation(train);
eval.crossValidateModel(svm, train, 10, new Random(1)); // 10-fold cross-validation
See: https://weka.wikispaces.com/LibSVM
Use Weka's package manager to install the LibSVM. Suppose "weka.jar" is in your current folder, than run this:
java -cp weka.jar weka.core.WekaPackageManager -install-package LibSVM
During the installation, it shows:
[DefaultPackageManager] Tmp file: /tmp/LibSVM1.0.107382715397815864641.zip
[DefaultPackageManager] Installing: Description.props
[DefaultPackageManager] Installing: LibSVM.jar
[DefaultPackageManager] Installing: build_package.xml
...
You can see that "LibSVM.jar" is installed somewhere. In my case, it is at:
/home/john/wekafiles/packages/LibSVM/LibSVM.jar
I want to use matlab function in java application. I create java package from my function by deploytool in matlab. Now, how can i use this package? Can only import the jar file created by deploytool in my java project and use its function?
After a lot of googling, I used this toturial but in the final step, i get error "could not load file".
Also i read about MatlabControl, but in this solution, we should have matlab environment in our system to java code running. But i will run my final app in systems that may not have matlab at all.
So i need a solution to run matlab function in java class even in absence of matlab environment.
Finally I solve my problem. the solution step by step is as follows:
write matlab function:
function y = makesqr(x)
y = magic(x);
Use deploytool in matlab and create java package.
3.create new java application in Eclipse and add main class. import javabuilde.jar and makesqr.jar:
import com.mathworks.toolbox.javabuilder.MWArray;
import com.mathworks.toolbox.javabuilder.MWClassID;
import com.mathworks.toolbox.javabuilder.MWNumericArray;
import makesqr.Class1;
and main.java:
public class main {
public static void main(String[] args) {
MWNumericArray n = null;
Object[] result = null;
Class1 theMagic = null;
try
{
n = new MWNumericArray(Double.valueOf(5),MWClassID.DOUBLE);
theMagic = new Class1();
result = theMagic.makesqr(1, n);
System.out.println(result[0]);
}
catch (Exception e)
{
System.out.println("Exception: " + e.toString());
}
finally
{
MWArray.disposeArray(n);
MWArray.disposeArray(result);
theMagic.dispose();
}
}
}
add javabuilder.jar and makesqr.jar to java build path of your project.
run it.
the Double.valueOf(3), define the input for our function and the output is as follows:
8 1 6
3 5 7
4 9 2
I didn't get properly your problem. Did you already compile the jar file from Matlab code and you are trying to use that, or you are at the last step of the tutorial?
If your answer is the latest case, most probably you forgot the "." before the class path.
From tutorial you linked:
You must be sure to place a dot (.) in the first position of the class path. If it not, you get a message stating that Java cannot load the class.
Also check if the matlab compiler path ("c:\Program Files\MATLAB\MATLAB Compiler Runtime\v82\toolbox\javabuilder\jar\javabuilder.jar" - in the tutorial) is correct for your system.
i want to query existdb from Java. i know there are samples but where can i get the necessary packages to run the examples?
in the samples :
import javax.xml.transform.OutputKeys;
import org.exist.storage.serializers.EXistOutputKeys;
import org.exist.xmldb.EXistResource;
import org.xmldb.api.DatabaseManager;
import org.xmldb.api.base.Collection;
import org.xmldb.api.base.Database;
import org.xmldb.api.modules.XMLResource;
where can i get these ?
and what is the right standard connection string for exist-db? port number etc
and YES, i have tried to read the existdb documentation, but those are not really understandable for beginners. they are confusing.
All i want to do is write a Java class in eclipse that can connect to a exist-db and query an xml document.
Your question is badly written, and I think you are really not explaining what you are trying to do very well.
If you want the JAR files as dependencies directly for some project then you can download eXist and get them from there. Already covered several times here, which JAR files you need as dependencies is documented on the eXist website and links to that documentation have already been posted in this thread.
I wanted to add, that if you did want a series of simple Java examples that use Maven to resolve the dependencies (which takes away the hard work), then when we wrote the eXist book we provided just that in the Integration Chapter. It shows you how to use each of eXist's different APIs from Java for storing/querying/updating etc. You can find the code from that book chapter here: https://github.com/eXist-book/book-code/tree/master/chapters/integration. Included are the Maven project files to resolve all the dependencies and build and run the examples.
If the code is not enough for you, you might also want to consider purchasing the book and reading the Integration Chapter carefully, that should answer all of your questions.
i ended up with a maven project and imported some missing jars (like ws.commons etc) by manually installing them on maven.
the missing jars i copied from the existdb installation path on my local system.
then i got it to work.
from: http://exist-db.org/exist/apps/doc/devguide_xmldb.xml
There are several XML:DB examples provided in eXist's samples
directory . To start an example, use the start.jar jar file and pass
the name of the example class as the first parameter, for instance:
java -jar start.jar org.exist.examples.xmldb.Retrieve [- other
options]
Example: Retrieving a Document with XML:DB
import org.xmldb.api.base.*;
import org.xmldb.api.modules.*;
import org.xmldb.api.*;
import javax.xml.transform.OutputKeys;
import org.exist.xmldb.EXistResource;
public class RetrieveExample {
private static String URI = "xmldb:exist://localhost:8080/exist/xmlrpc";
/**
* args[0] Should be the name of the collection to access
* args[1] Should be the name of the resource to read from the collection
*/
public static void main(String args[]) throws Exception {
final String driver = "org.exist.xmldb.DatabaseImpl";
// initialize database driver
Class cl = Class.forName(driver);
Database database = (Database) cl.newInstance();
database.setProperty("create-database", "true");
DatabaseManager.registerDatabase(database);
Collection col = null;
XMLResource res = null;
try {
// get the collection
col = DatabaseManager.getCollection(URI + args[0]);
col.setProperty(OutputKeys.INDENT, "no");
res = (XMLResource)col.getResource(args[1]);
if(res == null) {
System.out.println("document not found!");
} else {
System.out.println(res.getContent());
}
} finally {
//dont forget to clean up!
if(res != null) {
try { ((EXistResource)res).freeResources(); } catch(XMLDBException xe) {xe.printStackTrace();}
}
if(col != null) {
try { col.close(); } catch(XMLDBException xe) {xe.printStackTrace();}
}
}
}
}
On the page http://exist-db.org/exist/apps/doc/deployment.xml#D2.2.6 a list of dependencies is included; unfortunately there is no link to this page on http://exist-db.org/exist/apps/doc/devguide_xmldb.xml (should be added);
The latest xmldb.jar documentation can be found on http://xmldb.exist-db.org/
All the jar files can be retrieved by installing eXist-db from the installer jar; the files are all in EXIST_HOME/lib/core
If you work with a maven project, try adding this to your pom.xml
<dependency>
<groupId>xmldb</groupId>
<artifactId>xmldb-api</artifactId>
<version>20021118</version>
</dependency>
Be aware that the release date is 2002.
Otherwise you can query exist-db via XML-RPC
I researched and looked into the PlayN game framework and I liked it a lot. I program in Scala and actually don't know Java but it's not usually a problem since they work together great.
I've set up a basic project in eclipse and imported all the libraries and dependencies. I even translated over the base maven project code. Here's the two files:
Zeitgeist.scala
package iris.zeit.core
import playn.core.PlayN._
import playn.core.Game
import playn.core.Image
import playn.core.ImageLayer
class Zeitgeist extends Game {
override def init (){
var bgImage: Image = assets().getImage("images/bg.png")
var bgLayer: ImageLayer = graphics().createImageLayer(bgImage)
graphics().rootLayer().add(bgLayer)
}
override def paint (alpha: Float){
//painting stuffs
}
override def update(delta: Float){
}
override def updateRate(): Int = {
25
}
}
Main.scala
package iris.zeit.desktop
import playn.core.PlayN
import playn.java.JavaPlatform
import iris.zeit.core.Zeitgeist
object Main {
def main(args: Array[String]){
var platform: JavaPlatform = JavaPlatform.register()
platform.assets().setPathPrefix("resources")
PlayN.run(new Zeitgeist())
}
}
The cool thing is it works! A window comes up perfectly. The only problem is I can't seem to load images. With the above line, "assets().getImage("images/bg.png")" it pops out
Could not load image: resources/images/bg.png [error=java.io.FileNotFoundException: resources/images/bg.png]
I've played around with the location of my resources file to no avail. I was even able to find bg.png myself with java.io.File. Am I doing something wrong? Is there something I'm forgetting?
Looking at the code of JavaAssetsManager, it looks like it is trying to load a resource and not a file. So you should check that your images are actually in the classpath and at the path you give ("resources/images/bp.png")
Alternatively, you can use getRemoteImage and pass a File URL. As you succeeded in using a java.io.File, you can just get the URL with method toUri of File (toUrl is deprecated).
This almost certainly doesn't work because you're doing this:
platform.assets().setPathPrefix("resources")
That means you're saying your source folder looks like this:
src/main/resources/resources/images/bg.png
src/main/resources/resources/images/pea.png
src/main/resources/resources/images
I imagine it actually looks like one of these:
src/main/resources/assets/images/bg.png <-- 'assets' the default prefix
src/main/resources/assets/images/pea.png
src/main/resources/assets/images
or:
src/main/resources/images/bg.png <-- You have failed to put a subfolder prefix in
src/main/resources/images/pea.png
src/main/resources/images
You can either do this, if you have no prefix:
plat.assets().setPathPrefix("")
Or just put your files in the assets sub-folder inside the resources folder.
It's worth noting that the current implementation calls:
getClass().getClassLoader().getResource(...)
Not:
getClass().getResource(...)
The difference is covered elsewhere, but the tldr is that plat.assets.getImage("images/pea.png") will work, but plat.assets.getImage("/images/pea.png") will not.
I have a third-party jar file that comes with the javadocs for only part of the API. Is there a way to reverse engineer the jar file to obtain a complete listing of classes and methods?
jar tf will list the contents for you. javap will allow you to see more details of the classes (see the tools guide).
For instance if you have a class named mypkg.HelloWorld in a jar myjar.jar then run it like
javap -classpath myjar.jar mypkg.HelloWorld
However, are you sure you want to be using these unpublished APIs? It's usually a really bad idea.
As Scott said, you can use Eclipse to get a lot of what you're looking for.
I would recommend getting the JadClipse plugin which will decompile the .class files on the fly and show you actual Java code as you browse the classes in the IDE.
If you're using eclipse, you can just add it to a project's classpath and explore it using the treeview and/or content assist.
I'd assume other IDEs can do similar.
From a command-line point of view, you can unjar it (jar xf foo.jar) and use javap against all files.
Eclipse would work great
A Java Decompiler would translate the classes back into some semblence of source code that you could study to learn about the classes, the methods, their signatures, and maybe even some insight into valid values for some arguments (e.g. don't pass a null for this argument or you'll trigger a NullPointerException immediately). But roll up your sleeves to unjar the jar and run the decompiler against all the class files. This is essentially what Eclipse is doing for help text with undocumented classes.
Finally, of course, a "real programmer" would read the byte-code directly without need for a decompiler.
You can use the library WALA to read out all methods signatures. You'll however need to load Stub-Code for Java first. The following program should read out all the signatures:
import com.ibm.wala.ipa.cha.ClassHierarchy;
import com.ibm.wala.ipa.cha.IClassHierarchy;
import com.ibm.wala.classLoader.IClass;
import com.ibm.wala.classLoader.IMethod;
import com.ibm.wala.ipa.callgraph.AnalysisOptions;
import com.ibm.wala.ipa.callgraph.AnalysisScope;
import com.ibm.wala.types.ClassLoaderReference;
import java.util.jar.JarFile;
import java.io.IOException;
import com.ibm.wala.ipa.cha.ClassHierarchyException;
public class methods {
public static void main(String[] args) throws IOException, ClassHierarchyException {
AnalysisScope scope = AnalysisScope.createJavaAnalysisScope();
scope.addToScope(ClassLoaderReference.Primordial, new JarFile("jSDG-stubs-jre1.5.jar"));
scope.addToScope(ClassLoaderReference.Application, new JarFile("myProgram.jar"));
IClassHierarchy cha = ClassHierarchy.make(scope);
for (IClass cl : cha) {
if (cl.getClassLoader().getReference().equals(ClassLoaderReference.Application)) {
for (IMethod m : cl.getAllMethods()) {
String ac = "";
if (m.isAbstract()) ac = ac + "abstract ";
if (m.isClinit()) ac = ac + "clinit ";
if (m.isFinal()) ac = ac + "final ";
if (m.isInit()) ac = ac + "init ";
if (m.isNative()) ac = ac + "native ";
if (m.isPrivate()) ac = ac + "private ";
if (m.isProtected()) ac = ac + "protected ";
if (m.isPublic()) ac = ac + "public ";
if (m.isSynchronized()) ac = ac + "synchronized ";
System.out.println(ac + m.getSignature());
}
}
}
}
}
If you use the adapted WALA-version from here it does Dalvik (e.g. Android Apps) as well.
a quick help for knowing methods of a normal class (not abstract class),I do the following .
new classname().press ctrl+space for methods listing in eclipse.
Use Eclipse > Package Explorer to see the classes and thier hierarchy.
Content Assist(autocomplete feature (ctrl + space)) is also a good help , but wouldnt recomend using an unpublished API