Develop Reference

Auto document time of creation of new Java class

When I create a new Java file in NetBeans, I get auto documentation for #author. How can I setup NetBeans that is also documents the time and date of creation of the class?
I know NetBeans can do it as I get the time and date of creation in new CSS files by default.

You can change the template files in Netbeans. Go to Tools|Templates. From the available templates, find the one you want to change, let's say Java|Java Class, then select Open in Editor
Then goto to FaqTemplateVariables for list of available template variables. In your case, you're looking for ${date} and {$time}
Then you modify the template the way want, for example...
<#assign licenseFirst = "/*">
<#assign licensePrefix = " * ">
<#assign licenseLast = " */">
<#include "${project.licensePath}">
<#if package?? && package != "">
package ${package};
</#if>
/**
*
* #author ${user}
* ${date} ${time}
*/
public class ${name} {
}
Then simple create a new "Java Class" - File|New File|Java|Class and it should then generate a file similar to this...
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package my.awesome.library;
/**
*
* #author noob
* 25/06/2017 3:19:39 PM
*/
public class Test {
}
Now, you'll probably have to go through a number of the other templates and update them, but that gives you a place to start

#MadProgrammer answered well. Just in case as an addition to this answer. U can optionally add properties in the User.properties file which is read by the various templates in the Tools -> Templated ->* configs. So if u want to add version to your Java classes. you can define the #version in the Java class template and then define the property in the User.properties file as in the following
In Your Java class template
....
/**
* ${date} ${time}
* ${version}
* ...other
*/
U can then set these properties in the User.properties file as
version=1.0.0
etc

UnsatisfiedLinkError: no opencv_java249 in java.library.path

Running into some problems making a piece of code run on my mac.
Had someone write me an image analysis java app but I keep getting this error when trying to run it on netbeans.
run: Exception in thread "main" java.lang.UnsatisfiedLinkError: no
opencv_java249 in java.library.path at
java.lang.ClassLoader.loadLibrary(ClassLoader.java:1857) at
java.lang.Runtime.loadLibrary0(Runtime.java:870) at
java.lang.System.loadLibrary(System.java:1119) at
image.prossing.Test.main(Test.java:28) Java Result: 1 BUILD SUCCESSFUL
(total time: 0 seconds)
Have the netbeans project, and added the necessary jar files as libraries. The programmer told me to download the correct OpenCV version and copy the opencv.dll file to my java/jre/bin folder. But I cannot find the dll file or the java/jre folder.
I know most programming happens on windows for a reason. Hope someone can help me resolve this issue and run this application on my mac.
Here is the first part of the code, the part that is most probably creating the error:
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package image.prossing;
/**
*
* #author Dumith Salinda
*/
import java.util.ArrayList;
import java.util.List;
import org.opencv.core.Core;
import static org.opencv.core.Core.FONT_HERSHEY_SIMPLEX;
import org.opencv.core.Mat;
import org.opencv.core.MatOfPoint;
import org.opencv.core.Point;
import org.opencv.core.Rect;
import org.opencv.core.Scalar;
import org.opencv.highgui.Highgui;
import org.opencv.imgproc.Imgproc;
public class Test {
public static void main(String[] args) {
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
Sorry if it's not that clear, let me know what info to add if something is missing or not clear.
Would truly appreciate any help you could give. Sincerely
Meir Warcel

Look into your OpenCV directory;
For an example this; (installed using brew install opencv3 --with-java --with-python3)
/usr/local/Cellar/opencv3/XXX/share/OpenCV/java
You will see;
libopencv_javaXXX.so opencv-XXX.jar
Now that you already have OpenCV's native library for Java (libopencv_javaXXX.so) compiled with you, the only thing left is, mac's dynamic library.
Link libopencv_javaXXX.so to libopencv_javaXXX.dylib;
ln -s libopencv_javaXXX.so libopencv_javaXXX.dylib
Now add /usr/local/Cellar/opencv3/XXX/share/OpenCV/java as Native Library Locations in IntelliJ or something similar in Eclipse.
Or add this to your JVM arguments;
-Djava.library.path=/usr/local/Cellar/opencv3/XXX/share/OpenCV/java

On a mac running OSX Yosemite, I dropped the libopencv_java2412.dylib file into /Library/Java/Extensions and it worked.
After you build opencv, the libopencv_java2412.dylib is generated in /build/lib.

After Spending a lots of time , and using different suggestions from StackOverflow I managed to get solution for windows. but I am adding a solution for mac as well. hope it should work.
Load your lib as per your system configuration.
private static void loadLibraries() {
try {
InputStream in = null;
File fileOut = null;
String osName = System.getProperty("os.name");
String opencvpath = System.getProperty("user.dir");
if(osName.startsWith("Windows")) {
int bitness = Integer.parseInt(System.getProperty("sun.arch.data.model"));
if(bitness == 32) {
opencvpath=opencvpath+"\\opencv\\x86\\";
}
else if (bitness == 64) {
opencvpath=opencvpath+"\\opencv\\x64\\";
} else {
opencvpath=opencvpath+"\\opencv\\x86\\";
}
}
else if(osName.equals("Mac OS X")){
opencvpath = opencvpath+"Your path to .dylib";
}
System.out.println(opencvpath);
System.load(opencvpath + Core.NATIVE_LIBRARY_NAME + ".dll");
} catch (Exception e) {
throw new RuntimeException("Failed to load opencv native library", e);
}
}
2.now use this method as per your need
public static void main(String[] args) {
loadLibraries();
}

Building on Harsh Vakharia's answer i tried installing OpenCV on my mac with macports:
sudo port install opencv +java
ls /opt/local/share/OpenCV/java
libopencv_java343.dylib opencv-343.jar
To use this library I was hoping to be able to modify the library path at runtime which was discussed in
Adding new paths for native libraries at runtime in Java
And ended up with the following helper class and unit test. The code is now part of the
Self Driving RC-Car open Source project in which I am a comitter.
JUnit Test
/**
* #see <a href=
* 'https://stackoverflow.com/questions/27088934/unsatisfiedlinkerror-no-opencv-java249-in-java-library-path/35112123#35112123'>OpenCV
* native libraries</a>
* #throws Exception
*/
#Test
public void testNativeLibrary() throws Exception {
if (debug)
System.out.println(String.format("trying to load native library %s",
Core.NATIVE_LIBRARY_NAME));
assertTrue(NativeLibrary.getNativeLibPath().isDirectory());
assertTrue(NativeLibrary.getNativeLib().isFile());
NativeLibrary.load();
}
NativeLibrary
package com.bitplan.opencv;
import java.io.File;
import java.lang.reflect.Field;
import java.util.Arrays;
import org.opencv.core.Core;
/**
* load OpenCV NativeLibrary properly
*/
public class NativeLibrary {
protected static File nativeLibPath = new File("../lib");
/**
* get the native library path
*
* #return the file for the native library
*/
public static File getNativeLibPath() {
return nativeLibPath;
}
/**
* set the native library path
*
* #param pNativeLibPath
* - the library path to use
*/
public static void setNativeLibPath(File pNativeLibPath) {
nativeLibPath = pNativeLibPath;
}
/**
* get the current library path
*
* #return the current library path
*/
public static String getCurrentLibraryPath() {
return System.getProperty("java.library.path");
}
/**
* Adds the specified path to the java library path
*
* #param pathToAdd
* the path to add
* #throws Exception
* #see <a href=
* 'https://stackoverflow.com/questions/15409223/adding-new-paths-for-native-libraries-at-runtime-in-java'>Stackoverflow
* question how to add path entry to native library search path at
* runtime</a>
*/
public static void addLibraryPath(String pathToAdd) throws Exception {
final Field usrPathsField = ClassLoader.class.getDeclaredField("usr_paths");
usrPathsField.setAccessible(true);
// get array of paths
final String[] paths = (String[]) usrPathsField.get(null);
// check if the path to add is already present
for (String path : paths) {
if (path.equals(pathToAdd)) {
return;
}
}
// add the new path
final String[] newPaths = Arrays.copyOf(paths, paths.length + 1);
newPaths[newPaths.length - 1] = pathToAdd;
usrPathsField.set(null, newPaths);
}
public static File getNativeLib() {
File nativeLib = new File(getNativeLibPath(),
"lib" + Core.NATIVE_LIBRARY_NAME + ".dylib");
return nativeLib;
}
/**
* load the native library by adding the proper library path
*
* #throws Exception
* - if reflection access fails (e.g. in Java9/10)
*/
public static void load() throws Exception {
addLibraryPath(getNativeLibPath().getAbsolutePath());
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
}
}

Exception is occurring from below line of code:
System.loadLibrary(Core.NATIVE_LIBRARY_NAME);
Your program is trying to load a native library by the name of argument in call to loadLibrary method, which it is not able to locate. Make sure that native library (opencv.dll) is placed at one of the locations present in java.library.path system property as JVM looks at these locations for loading any native library (which might not contain 'java/jre/bin').
You can print java.library.path in your program like below:
System.out.println(System.getProperty("java.library.path"));

You cannot just put Windows library (dll file) on Mac and have it running - you need to compile the library for Mac first (or get Mac version of the library).
Please see here for tips on how to do it:
.dll Equivalent on Mac OS X
How do third-party libraries work in Objective-C and Xcode?
How to use a Windows DLL with Java in Mac OS X?

Instead of struggling with manual installation of OpenCV libraries I suggest you use OpenCV Java library packaged by OpenPnP (https://github.com/openpnp/opencv) that includes all required DLL.
It does not require additonal steps except of adding it to your build automation tool configuration (Gradle in my case) and adding the following code to load the library:
System.loadLibrary(org.opencv.core.Core.NATIVE_LIBRARY_NAME);

Just add into the path the folder where your opencv_java249.dll is; it would be something like C:\bin\opencv\build\java\x32 or C:\bin\opencv\build\java\x64 depending of your machine architecture. The problem is that java.library.path is actually the path variable.

netebans right klick project chosew properti
chose run, working direktory, click Browser change to opencv folder, release/lib,

javadoc "#author" not showing?

Whenever I type in "Printing" and hit CTRL Q in intelliJ I can only see the "Summary" and I cant see "Bob" . . . what am I doing wrong?
package printing;
/**
* #author Bob
* <b>Summary</b>
*/
public class Printer {
//stuff
}
***Note: I am just learning how to use the "javadoc" so I would appreciate an explanation.
EDIT: I cant even see "Summary" unless I take out the "#author"

Sounds like a problem/feature of IntelliJ. Eclipse shows whole javadoc including #author. Other possible problem is a presence of <b>Summary</b> right after #author.
So, try to remove the summary and see what happens. Try also to really generate javadoc, e.g. run javadoc utility from command line and see what happens. I am sure that in this case Bob will appear. Good luck.

I can reproduce this behavior and have raised an issue to track this : http://youtrack.jetbrains.com/issue/IDEA-114499
Here is the bit of code I used:
package printing;
/**
* #author Simba
* #version 1
* #see java.util.Arrays
* #since 1
*/
public class Printer {
}
And the resulting documentation:
However, if you try to generate the javadoc via Tools -> Generate JavaDoc with the following settings :
then, the resulting generated javadoc does show the author tag:
therefore proving that the javadoc itself is sound and that it is IntelliJ that does not display it.

When javadoc is used from the console, you can add the -author and -version options to the call like this (-d sets the output directory):
javadoc src/main/java/com/*.java -d src/docs/javadocs/ -author -version
Author and version are displayed using those settings.
The javadoc help (by just typing javadoc) shows the following - as AlexR already mentioned - (shortened):
...
Provided by Standard doclet:
-d <directory> Destination directory for output files
-use Create class and package usage pages
-version Include #version paragraphs
-author Include #author paragraphs
...

If you do in command line you can use this:
javadoc -d javadoc -author -version YourClass.java
Change the name of the .java to your class name.
Is necessary add -author if you want to show the author tag and the same with the version -version
Remember, the -d argument is used to define the folder and depend of your actual path, so if you are in C:\Users\joselito your javadoc folder has to be in C:\Users\joselito\javadoc

When you click on generate Javadoc then you will find some options .
Go to below the output directory .
Tick the author option .
// this is for intellij Idea.

Eclipse: saved LaunchConfiguration overrides LaunchType

Not sure if it will be Eclipse or Eclipse-plugin-dev answer.
In open-source Nodeclipse project plugin.xml defines that .coffee file can be launched as coffee, coffee --compile or Node with monitor (There are 3 defined LaunchShortcuts).
First time it work fine, but then consequent launches only repeat previous LaunchType. I have found that deleting saved LaunchConfiguration (from Run -> Run Configurations) will let it run again (and then only as this type again)
The code in question is LaunchShortcut (see snippet below), however there is no any if checking, so this behavior should be deeper in Eclipse org.eclipse.debug module.
How can saved LaunchConfiguration override LaunchType ?
/**
* Launch an file,using the file information, which means using default
* launch configurations.
*
* #param file
* #param mode
*/
private void launchFile(IFile file, String mode) throws CoreException {
// check for an existing launch config for the file
String path = file.getFullPath().toString();
ILaunchManager launchManager = DebugPlugin.getDefault().getLaunchManager();
ILaunchConfigurationType type = launchManager.getLaunchConfigurationType(Constants.LAUNCH_CONFIGURATION_TYPE_ID);
ILaunchConfiguration configuration = createLaunchConfiguration(type, path, file);
DebugUITools.launch(configuration, mode);
// then execution goes in LaunchConfigurationDelegate.java launch() method
}
/**
* Create a new configuration and set useful data.
*
* #param type
* #param path
* #param file
* #return
* #throws CoreException
*/
private ILaunchConfiguration createLaunchConfiguration(ILaunchConfigurationType type, String path, IFile file) throws CoreException {
String configname = file.getFullPath().toString().replace('/', '-');
if(configname.startsWith("-")) {
configname = configname.substring(1);
}
ILaunchConfiguration[] configs = DebugPlugin.getDefault().getLaunchManager().getLaunchConfigurations(type);
for(ILaunchConfiguration config : configs) {
if(configname.equals(config.getName())) {
return config;
}
}
// create a new configuration for the file
ILaunchConfigurationWorkingCopy workingCopy = type.newInstance(null, configname);
workingCopy.setAttribute(Constants.KEY_FILE_PATH, path);
setMoreAttributes(workingCopy);
return workingCopy.doSave();
}
protected void setMoreAttributes(ILaunchConfigurationWorkingCopy workingCopy) {
// stub for extension
}
Help! The code snippet is maybe not enough to answer the question, but references files and everything is in Github repository. The question was raised, because I am not sure if it is possible at all to have many Run Configuration for the same file. Then code snippets doesn't matter at all.
Update: Looking after a while at plugin.xml defines that .coffee file can be launched , I noticed that I am actually using the same <configurationType
id= "org.nodeclipse.debug.launch.LaunchConfigurationType" > in all 5 cases. However adding unique LaunchConfigurationType id for every launch makes no difference.

You can create the launch configuration with this:
Creating a Java application launch configuration
Launch groups can also be setle with this help:
Launch Group
Until here Im pretty sure you have knowledge about, so lets keep moving; You can have different launch configuration for the same file, thats handled with the launch group tool, what I dont get is if you want those different configuration for the same environment or not.
Also here Launch Configuration Types and here Adding launchers to the platform you cand find information about the struct of the launch type file
To finish here Interface ILaunchConfigurationTabGroup is the interface of the launch type tab group;
My Suggestion in codelines:
<extension point="org.eclipse.debug.ui.launchConfigurationTabGroups">
<launchConfigurationTabGroup
<"launchConfigurationType1"
<"/launchConfigurationType1">
<"launchConfigurationType2"
<"/launchConfigurationType2">
//and so on...
</launchConfigurationTabGroup>
</extension>

Hello world doesn't run in IntelliJ Idea

I have worked many years with Eclipse. After decided try IntelliJ Idea. Bua also simple java Hello World doesn't run! It is simply happens nothing. What should I check/adjust?
Thanks.
package test;
/** * Created with IntelliJ IDEA.
* Date: 16/06/12
* Time: 12:13
* To change this template use File | Settings | File Templates.
*/
public class Main {
public static void main(String ...args)
{ System.out.println("Hello World"); }
}

It is because of problem with shared network disk.
If default user folder on shared network disk IntelliJ will not work correct.
Find idea.properties and fix paths don't use shared network disk