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how to further debug to expose the values in the element in groovy script

Hi i am new to groovy and i have an issue that i am facing. Currently i am trying to see the values inside typeCache[alias] which seems to be a hashtable.
protected static Hashtable typeCache = new Hashtable();
logger.error "this is type cache : " + typeCache[alias].get(indx)[1];
when i output the element i get the following result in the logs :-
this is type cache : [com.abcd.util.TypeElement#5dc97ce, com.abcd.util.TypeElement#270a8a6, com.abcd.util.TypeElement#5d421487]
am i able to expose further on the elements to see what is in them and what is it doing ?? i am used to php programming and usually in situations such as this i would do a var_dump is there an equivalent of var_dump in groovy ??
thank you.

Each object has a method, which generates a
public String dump()
Generates a detailed dump string of an object showing its class, hashCode and fields. http://docs.groovy-lang.org/latest/html/groovy-jdk/java/lang/Object.html#dump%28%29
This post contains an example, but make sure to read the comment, as the answer is not corrected as of yet.

java associative array sort of thing with more than one data type

imagine this:
DataTypeForConfigs config
with
String keys, but values of either String, Integer, or Boolean,
in Java, JSON can do that, but I'm making a format That goes along the lines of:
number "coolness" is 9001 means
int coolness = 9001;
It's method is: Read line, read each word, think what to make of it, set it to a Variable within it's reach
Also: what would happen if another thing had its own place to put config? a null would be read? WHY? constructor thinks a file has null on it? Rage face.
Say... should I make a class called SettingVal that when given a getValue() call it would say what it is?
SO:
config["Coolness"].getValue();
return's 9001
WAIT:
How on earth would I make the getValue() method? HOW? RETURN VALUE WONT LIKE THIS!! OH CRAP!
Solution:
Another Data type comes in and checks its 'gender' (String, Bool, Int) and then checks it's value of that 'gender' (strVal, boolVar, intVar)
Return values are a big problem when dealing with this. I need a stress free version, so maybe I can have a void returning method that runs another method based on what data type it is said to hold! Am I right?
I have a temporary solution, setVar works, getVar is get*Var, where * is Str, Bool or Int.
Sadly, I Haven't yet been able to properly read it from a file, the method I made to read from a file is not working. It makes a Map<String,SettingVar>, using a HashMap constructor and returns that map, but seems whenever I try to access a variable from it that variable is null. It is probably because of IOExceptions and FileNotFoundExceptions, FileNotFound? Why? It Shouldn't be running until called. Oh, and also NullPointerExceptions Please Help!
SUBQUESTION: what happens when you MapVariable.put({NAME HERE}, varToPutIn) many times in a for loop? what about MapVariable.put({NAME HERE},new ...)?
My code in links:
https://gist.github.com/anonymous/66c4d1c2d2718a4cc9b9
because I don't have enough reputation
P.S: OK! ive made the config reader work now, and SettingVar, and SettingContainer and im working on ConfigWriter which is good, now working on a prototype for a java command prompt like thing, and soon a WHOLE OS!! wait... java is an os. thats why java virtual machine... oh. Well, how can I close this question and turn the outcome into a revolutionary new thingy for kids who want to learn to code java *cough cough* especialy ones with higher learning ability than social ability... and like to hang around with mature people who dont bully them like all the kids in their school. (Wow, that was specific)

I would use a Plain Old Java Object which you can read from JSON.
class Config {
int coolness = 9001;
String hello = "world";
boolean cool = true;
}
This way you can have fields with a variety of types.

The type you're looking for is Map<String,Object>, but it is not type-safe and you'll have to do a bunch of casting:
Map<String,Object> config = new HashMap<>();
config.put("coolness",9001);
config.put("hello","world");
config.put("cool", true);
boolean cool = (Boolean) config.get("cool");
String hello = (String) config.get("world");
int coolness = (Integer) config.get("coolness");
Generally, I'd recommend creating a dedicated class for holding your configuration (each field = one property), which is strongly typed and doesn't require casting, and then use something like Jackson to serialize/deserialize it from json, yaml, or xml.
This provides structure to your configuration, and will cause any issues with malformed configurations to show up when you start your application/load your configuration, and not in the middle of your application.

SUBQUESTION: what happens when you MapVariable.put(varToPutIn) many times in a for loop?
A Map represents a mapping. If you do this:
Map<String, Object> map = new HashMap<>();
for (int i = 0; i < 10; i++) {
map.put("myKey", Integer.valueOf(i));
}
what happens is that you add a mapping from "myKey" to zero, then update it to one, two, three and so on. When the loop ends, "myKey" will map to nine.
In short, the map entry for "myKey" is behaving like a variable of type Integer that you assign to repeatedly.

I'm afraid your Gists are telling me that you simply didn't take on board what #Darth Android wrote. Rather that hashing through your code, here's a simple way to parse your config file syntax (more or less) and load it into a Map<String, Object>
Note: I have not compiled or tested this code. It is written to be read and understood, rather than borrowed.
Map<String,Object> config = new HashMap<>();
try (Scanner s = new Scanner(new FileReader(someFile))) {
while (s.hasNext()) {
// Syntax is '<type> <name> is <value>'
String[] words = s.nextLine().split("\\s+");
if (words.length != 4 || !words[2].equals("is")) {
throw MySyntaxException("unrecognizable config");
}
String type = words[0];
String name = words[1];
String val = words[3];
switch (type) {
case "number":
map.put(name, Integer.valueOf(val));
break;
case "boolean":
map.put(name, Boolean.valueOf(val));
break;
case "string":
map.put(name, val);
break;
default:
throw MySyntaxException("unknown type");
}
} catch (NumberFormatException ex) {
throw MySyntaxException("invalid number");
}
}

Java Enum Returns Null

I am currently creating a plugin for Minecraft using the SpigotAPI. Reason I'm posting this here is because this I believe is a Java error. I am creating a duels plugin where inside my code it'll loop through an enum, and see if it's a specific type. The first time using it around it properly works, no problems. But when I try it for a second time without restarting my plugin/program/code it'll return the enum as null. Here is the code, is there a fix to this?
public DuelArenas[] getArenasWithType(DuelTypes type) {
String suffix = "_NORMAL";
List<DuelArenas> arenasAsList = new ArrayList<>();
switch (type) {
case NORMAL:
suffix = "_NORMAL";
break;
}
for (DuelArenas arena : duelArenaStatus.keySet()) {
if (arena.toString().endsWith(suffix)) {
arenasAsList.add(arena);
}
}
DuelArenas[] arenas = new DuelArenas[arenasAsList.size()];
return arenasAsList.toArray(arenas);
}
Stacktrace:
Caused by: java.lang.NullPointerException
at me.nick.acore.duels.DuelsAPI.getArenasWithType(DuelsAPI.java:97) ~[?:?]
And yes I've checked to see if the enum was null, and it was in fact null. Also line 97 is
if (arena.toString().endsWith(suffix)) {
And finally here is the DuelArena class
public enum DuelArenas {
ARENA_1_NORMAL, ARENA_2_NORMAL, ARENA_3_NORMAL, ARENA_4_NORMAL, ARENA_5_NORMAL,
ARENA_6_NORMAL, ARENA_7_NORMAL, ARENA_8_NORMAL, ARENA_9_NORMAL, ARENA_10_NORMAL,
ARENA_11_NORMAL, ARENA_12_NORMAL }
Thanks!

Your problem is that you cannot directly convert your custom DuelArenas class to a string. However when you are comparing to see if a .toString() ends with suffix, I feel that something is also going wrong. You would only ever use .toString to convert things like numbers to strings, and if your are converting a number to a string there is no way it will end in _NORMAL.
So if you want me to troubleshoot further please post your DuelArenas class, but until then my best guess is that when you do arena.toString you are looking to pull some sort of value from that class that is stored in it, and to do this you would do arena.variableInsideArenaName and work with that.
EDIT:
After seeing the class scratch that, the error in going to be somewhere in this line DuelArenas arena : duelArenaStatus.keySet()

NullPointerException while using jruby

I embed jruby script engine into my java program by using javax.script.ScriptEngineManager
I made some jruby code that end with do ~ end block,
after running all code, NullPointerException occured.
but code ends with any other statement, no exception occurs.
version : 1.7.19
Caused by: java.lang.NullPointerException
at org.jruby.embed.variable.Argv.updateARGV(Argv.java:169)
at org.jruby.embed.variable.Argv.retrieve(Argv.java:158)
at org.jruby.embed.variable.VariableInterceptor.retrieve(VariableInterceptor.java:154)
at org.jruby.embed.internal.BiVariableMap.retrieve(BiVariableMap.java:378)
at org.jruby.embed.internal.EmbedEvalUnitImpl.run(EmbedEvalUnitImpl.java:124)
in ARGV.java updateARGV
if (vars.containsKey((Object)name)) {
var = vars.getVariable((RubyObject)receiver.getRuntime().getTopSelf(), name);
var.setRubyObject(argv);
vars.getVariable returned null because of isReceiverIdentical return false
in BiVariableMap.java
if (var.isReceiverIdentical(receiver)) {
return var;
}
In isReceiverIdentical, this method just compare receiver with BiVariable's receiver usgin '=='.
Is this jruby bug? Or do I have to do something for this?
If you need more information about this problem, plz comment it!
I got ScriptEngine(engine) from ScriptEngineManager and set some java instance and method like this
engine.put("this", console);
engine.eval("$command = $this.java_method :command, [java.lang.String]");
here is my test ruby code. result and tab is java object
that has some method return String and list.
result = $command.call "something to pass"
puts result.getMessage
tabular = result.getData
tabular.each do |tab|
rows = tab.getRows
rows.each do |row|
puts row
end
puts tab.getColumnNames
end

I had created ruby type object in my java code by creating new Ruby object...
This causes checking fail in updateARGV because a receiver that register variable in BiVariableMap and another receiver that update variable are different.
So, I got a Ruby object from new ScriptingContainer(from it we can always get a same Ruby object if local context is singleton) and used it to create new ruby type object in my java code.
Reference: https://github.com/jruby/jruby/wiki/RedBridge#Singleton

Get declared methods in order they appear in source code

The situation seems to be abnormal, but I was asked to build serializer that will parse an object into string by concatenating results of "get" methods. The values should appear in the same order as their "get" equivalent is declared in source code file.
So, for example, we have
Class testBean1{
public String getValue1(){
return "value1";
}
public String getValue2(){
return "value2";
}
}
The result should be:
"value1 - value2"
An not
"value2 - value1"
It can't be done with Class object according to the documentation. But I wonder if I can find this information in "*.class" file or is it lost? If such data exists, maybe, someone knows a ready to use tool for that purpose? If such information can't be found, please, suggest the most professional way of achieving the goal. I thought about adding some kind of custom annotations to the getters of the class that should be serialized.

If you want that you have to parse the source code, not the byte code.
There are a number of libraries that parse a source file into a node tree, my favorite is the javaparser (hosted at code.google.com), which, in a slightly modified version, is also used by spring roo.
On the usage page you can find some samples. Basically you will want to use a Visitor that listens for MethodDefinitions.

Although reflection does not anymore (as of java 7 I think) give you the methods in the order in which they appear in the source code, the class file appears to still (as of Java 8) contain the methods in the order in which they appear in the source code.
So, you can parse the class file looking for method names and then sort the methods based on the file offset in which each method was found.
If you want to do it in a less hacky way you can use Javassist, which will give you the line number of each declared method, so you can sort methods by line number.

I don't think the information is retained.
JAXB, for example, has #XmlType(propOrder="field1, field2") where you define the order of the fields when they are serialized to xml. You can implemenet something similar

Edit: This works only on concrete classes (the class to inspect has its own .class file). I changed the code below to reflect this. Until diving deeper into the ClassFileAnalyzer library to work with classes directly instead of reading them from a temporary file this limitation exists.
Following approach works for me:
Download and import following libarary ClassFileAnalyzer
Add the following two static methods (Attention! getClussDump() needs a little modification for writing out the class file to a temporary file: I removed my code here because it's very special at this point):
public static String getClassDump(Class<?> c) throws Exception {
String classFileName = c.getSimpleName() + ".class";
URL resource = c.getResource(classFileName);
if (resource == null) {
throw new RuntimeException("Works only for concreate classes!");
}
String absolutePath = ...; // write to temp file and get absolute path
ClassFile classFile = new ClassFile(absolutePath);
classFile.parse();
Info infos = new Info(classFile, absolutePath);
StringBuffer infoBuffer = infos.getInfos();
return infoBuffer.toString();
}
public static <S extends List<Method>> S sortMethodsBySourceOrder(Class<?> c, S methods) throws Exception {
String classDump = getClassDump(c);
int index = classDump.indexOf("constant_pool_count:");
final String dump = classDump.substring(index);
Collections.sort(methods, new Comparator<Method>() {
public int compare(Method o1, Method o2) {
Integer i1 = Integer.valueOf(dump.indexOf(" " + o1.getName() + lineSeparator));
Integer i2 = Integer.valueOf(dump.indexOf(" " + o2.getName() + lineSeparator));
return i1.compareTo(i2);
}});
return methods;
}
Now you can call the sortMethodsBySourceOrder with any List of methods (because sorting arrays is not very comfortable) and you will get the list back sorted.
It works by looking at the class dumps constant pool which in turn can be determined by the library.
Greetz,
GHad

Write your custom annotation to store ordering data, then use Method.getAnnotation(Class annotationClass)