Develop Reference

Non-Terminating Z3Str3 from z3-4.8.9-x64-ubuntu-16.04

I am having a problem when trying to use the Z3Str3 from z3-4.8.9-x64-ubuntu-16.04 notably if I substitute the com.microsoft.z3.jar to the one in z3-4.8.8-x64-ubuntu-16.04 I no longer have that issue. The problem is that the Z3 process never comes back with a result, despite the simplicity of the query. I noticed though that it returns the valid answer when I kill my program. I am not noticing that behavior when I am trying to run the same query on the executable, so I am guessing there is something about using the jar file that I might need to tweak one way or the other.
Here is my code. I am using Ubuntu 16.04 LTS, and IntelliJ version ultimate 2020.3.
Many thanks!
import com.microsoft.z3.*;
public class Z3String3Processor_reduced {
public static void main(String[] args) {
StringBuilder currentQuery = new StringBuilder("\n" +
"(declare-const string0 String)\n" +
"(assert (= (str.indexof string0 \"a\" 1) 6))\n" +
"(check-sat)\n" +
"(get-model)\n" +
"\n");
Context context1 = new Context();
Solver solver1 = context1.mkSolver();
Params params = context1.mkParams();
params.add("smt.string_solver", "z3str3");
solver1.setParameters(params);
StringBuilder finalQuery = new StringBuilder(currentQuery.toString());
// attempt to parse the query, if successful continue with checking satisfiability
try {
// throws z3 exception if malformed or unknown constant/operation
BoolExpr[] assertions = context1.parseSMTLIB2String(finalQuery.toString(), null, null, null, null);
solver1.add(assertions);
// check sat, if so we can go ahead and get the model....
if (solver1.check() == Status.SATISFIABLE) {
System.out.println("sat");
} else
System.out.println("not sat");
context1.close();
} catch (Z3Exception e) {
System.out.println("Z3 exception: " + e.getMessage());
}
}
}

I don't think this has anything to do with Java. Let's extract your query and put it in a file named a.smt2:
$ cat a.smt2
(declare-const string0 String)
(assert (= (str.indexof string0 "a" 1) 6))
(check-sat)
(get-model)
Now, if I run:
$ z3 a.smt2
sat
(
(define-fun string0 () String
"FBCADEaGaa")
)
That's good. But if I run:
$ z3 smt.string_solver=z3str3 a.smt2
... does not terminate ..
So, bottom line, your query (as simple as it looks), gives hard time to the z3str3 solver.
I see that you already reported this as a bug at https://github.com/Z3Prover/z3/issues/5673
Given that the default string-solver can handle the query just fine, why not just use that one? If you have to use z3str3 for some other reason, then you've found a case where it doesn't handle this query well; I'm not sure how inclined the z3 folks will be to fix this given the query is handled by the default solver rather quickly. Please report what you find out!

for-loop doesn't work in android try-catch block

I am making database of my school's building and classroom with Realm. But, 'for-loop' in try-catch doesn't work:
public void startCheckRealm() {
// Writing DataBase with Realm
try {
Log.d("Realm", "Init");
InitializeAPI.init_BuildingRoom(getActivity().getApplicationContext());
Log.d("Realm", "Complete");
} catch(Exception e) {
e.printStackTrace();
}
// Trying to check the Database whether it is right or wrong
try {
Log.d("Realm Test", "2nd Try Catch");
Realm.init(getActivity().getApplicationContext());
Realm realm = Realm.getDefaultInstance();
RealmResults<BuildingList> buildingLists = realm.where(BuildingList.class).findAllSorted("buildingCode");
int totalNumber = 0;
for(int i = 0; i < buildingLists.size(); i++) {
Log.d("For", "index = " + i);
RealmResults<RoomList> rooms = buildingLists.get(i).getRoomList().sort("roomCode");
String BuildingName = buildingLists.get(i).getBuildingName();
String BuildingCode = buildingLists.get(i).getBuildingCode();
for(int idx = 0; idx < rooms.size(); idx++) {
totalNumber++;
String RoomCode = rooms.get(idx).getRoomCode();
String RoomName = rooms.get(idx).getRoomName();
Log.d("Realm Test", "Number :: " + String.valueOf(totalNumber) + " BuildingCode :: " + BuildingCode + "\t\t BuildingName :: " + BuildingName + "\t\t RoomCode :: " + RoomCode + "\t\t RoomName :: " + RoomName);
}
}
Log.d("Realm Test", "2nd Try Catch Complete + " + String.valueOf(totalNumber));
} catch(RealmException e) {
e.printStackTrace();
}
}
In the first try-catch, the method, which does making database, is complete without Exception. I was curious whether this database is right or wrong.
So, in 2nd try-catch, I was trying to check realm files with queries.
The problem is "for-loop" doesn't work in 2nd try-catch. Below snippet is my logcat.
D/Realm: Init
I/System.out: bdList getLength :: 52
I/System.out: roomList getLength :: 2376
D/Realm: Complete
D/Realm Test: 2nd Try Catch
D/Realm Test: 2nd Try Catch Complete + 0
I want to check my realm data with Log but, doesn't work as you can see.
If there is no problem, the logcat shows lots of my building and room lists and ends with "D/Realm Test: 2nd Try Catch Complete + 2376".
Could you explain the reason why it doesn't work? I cannot understand the reason why it doesn't work even though there is no Exception.

While in your use-case this doesn't pose a problem, when you're iterating a RealmResults inside a transaction, the results are live in every version <= 0.88.3 and >= 3.0.0.
So in that case,
RealmResults<BuildingList> buildingLists = realm.where(BuildingList.class).findAllSorted("buildingCode");
for(int i = 0; i < buildingLists.size(); i++) {
BuildingList buildingList = buildingLists.get(i); // <-- !!!
will fail (it will skip every second item!)
So you should use iterators instead (3.0.0+! on <= 0.88.3 you'd do reverse iteration)
RealmResults<BuildingList> buildingLists = realm.where(BuildingList.class).findAllSorted("buildingCode");
for(BuildingList buildingList : buildingLists) { // <-- !!!
The reason why this works is because iterators by default create a new snapshot collection (3.0.0+), and iterating by index on a snapshot also works
OrderedRealmCollection<BuildingList> snapshot = buildingLists.createSnapshot();
for(int i = 0; i < ...

Simple: there is no exception thrown; and you only have your print statements inside the loop.
Thus the one and only conclusion: at that point in time when your for loops are executed, the corresponding list is empty. Therefore the loop body is not entered; nothing gets printed. And that has nothing to do with the fact that this loop is within a try-catch block.
That is all there is to this. So, the direct answer is: print the list size directly in front of the loop to avoid such surprises.
(of course, the interesting part is to understand what happens to the list which seems to be non-empty earlier on - but in order to debug that, you would have to add more of your code).

Two inputs:
1.Haven't used realm but looks like the syntax for getting sorted entriesis a bit different Official documentation
2.If the above point is wrong than from your code it looks like buildingList size is zero. Have you tried checking the size?
Let me know the results.

Try logging your catch block. Chances are the rest of the code including the loop didn't complete because your app was caught with the Exception.

You should debug buildingLists.size(); before for loop
Log.d("Building List Size ", buildingLists.size()+"");
In that case you can find the value of buildingLists.size();

java.lang.NullPointerException trying to get specific values from hashmap

I've spent several frustrating days on this now and would appreciate some help. I have a Java agent in Lotus Domino 8.5.3 which is activated by a cgi:POST from my Lotusscript validation agent which is checking that customer has filled in the Billing and delivery address form. This is the code that parses the incoming data into a HashMap where field names are mapped to their respective values.
HashMap hmParam = new HashMap(); //Our Hashmap for request_content data
//Grab transaction parameters from form that called agent (CGI: request_content)
if (contentDecoded != null) {
String[] arrParam = contentDecoded.split("&");
for(int i=0; i < arrParam.length; i++) {
int n = arrParam[i].indexOf("=");
String paramName = arrParam[i].substring(0, n);
String paramValue = arrParam[i].substring(n + 1, arrParam[i].length());
hmParam.put(paramName, paramValue); //Old HashMap
if (paramName.equalsIgnoreCase("transaction_id")) {
transactionID = paramValue;
description = "Order " + transactionID + " from Fareham Wine Cellar";
//System.out.println("OrderID = " + transactionID);
}
if (paramName.equalsIgnoreCase("amount")) {
orderTotal = paramValue;
}
if (paramName.equalsIgnoreCase("deliveryCharge")) {
shipping = paramValue;
}
}
}
The block of code above dates back over a year to my original integration of shopping cart to Barclays EPDQ payment gateway. In that agent I recover the specific values and build a form that is then submitted to EPDQ CPI later on in the agent like this;
out.print("<input type=\"hidden\" name=\"shipping\" value=\"");
out.println(hmParam.get("shipping") + "\">");
I want to do exactly the same thing here, except when I try the agent crashes with a null pointer exception. I can successfully iterate through the hashMap with the snippet below, so I know the data is present, but I can't understand why I can't use myHashMap.Get(key) to get each field value in the order I want them for the html form. The original agent in another application is still in use so what is going on? The data too is essentially unchanged String fieldnames mapped to String values.
Iterator it = cgiData.entrySet().iterator();
while (it.hasNext()) {
Map.Entry pairs = (Map.Entry)it.next();
out.println("<br />" + pairs.getKey() + " = " + pairs.getValue());
//System.out.println(pairs.getKey() + " = " + pairs.getValue());
}

I did two things that may have had an impact, in the process of trying to debug what was going on I needed these further imports;
import java.util.Iterator;
import java.util.Map;
Although I'm not iterating over the hashMap, I've left them in in case which gives me the option of dumping the hashMap out to my system audit trail when application is in production. In variations of the snippet below after it started working I was able to get to any of the data I needed, even if the value was Null, and toString() also seemed to be optional again, as it made no difference to the output.
String cgiValue = "";
cgiValue = hmParam.get("ship_to_lastname").toString();
out.println("<br />Lastname: " + cgiValue);
out.println("<br />Company name: " + hmParam.get("bill_to_company"));
out.println("<br />First name: " + hmParam.get("ship_to_firstname"));
The second thing I did, while trying to get code to work was I enabled the option "Compile Java code with debugging information" for the agent, this may have done something to the way the project was built within the Domino Developer client.
I think I have to put this down to some sort of internal error created when Domino Designer compiled the code. I had a major crash last night while working on this which necessitated a cold boot of my laptop. You also may find that when using Domino Designer 8.5.x that strange things can happen if you don't completely close down all the tasks from time to time with KillNotes

Cannot Teleport a Player to coordinates set in a config file [Bukkit]

So I am basicly making a Warping system but I am using it for a minigame. I want the owners of the server to be able to set the warp for the different players to spawn in when the minigame starts. For some reason, I am getting a error which is saying that I cannot teleport the player, here is my code for the teleporting part:
if(cmd.getName().equalsIgnoreCase("cakestart")){
if(getConfig().contains("locations." + args[0])){
int locationsX = this.getConfig().getInt("locations" + args[0] + ".X");
int locationsY = this.getConfig().getInt("locations" + args[0] + ".Y");
int locationsZ = this.getConfig().getInt("locations" + args[0] + ".Z");
int locationsYaw = this.getConfig().getInt("locations" + args[0] + ".Yaw");
int locationsPitch = this.getConfig().getInt("locations" + args[0] + ".Pitch");
Object locationsworld = this.getConfig().get("locations" + args[0] + ".World");
Location cakestart = new Location((World) locationsworld, locationsX, locationsY, locationsZ, locationsYaw, locationsPitch);
p.teleport(cakestart);
p.sendMessage("TPED!");
}
}
The error is happening with:
p.teleport(cakestart);
I can give any more info you need.

I would suggest that instead of
Object locationsworld = this.getConfig().get("locations" + args[0] + ".World");
Location cakestart = new Location((World) locationsworld, locationsX, locationsY, locationsZ, locationsYaw, locationsPitch);
You instead define locationsworld as a string, and then fetch the actual world from the server using it's unique case-sensitive name. Assuming you're in your main class that extends JavaPlugin, it would look like this:
String locationsworld = this.getConfig().get("locations" + args[0] + ".World");
World tworld = this.getServer().getWorld(locationsworld);
Location cakestart = new Location(tworld, locationsX, locationsY, locationsZ, locationsYaw, locationsPitch);
That way you don't have an invalid world. There's a lot more info in the world class that just a name, and unless you're saving all of it instead of just the World.getName();, you're not going to have much success with a typecast.
EDIT: Afterthought: You would also probably do well to use doubles instead of integers for the other values, especially pitch and yaw.

It is possible that the Object cannot be cast to the World object. I would try saving the world as a string and parsing it to a world object using Bukkit.getWorld("string");.
To get a World from the config all you have to do is this:
Bukkit.getWorld(getConfig().getString("path of the world in the config");

Obtain a share UpdateKey from LinkedIn using LinkedIn J and getNetworkUpdates() with Coldfusion

Using the "Network Updates API" example at the following link I am able to post network updates with no problem using client.postNetworkUpdate(updateText).
http://code.google.com/p/linkedin-j/wiki/GettingStarted
So posting works great.. However posting an update does not return an "UpdateKey" which is used to retrieve stats for post itself such as comments, likes, etc. Without the UpdateKey I cannot retrieve stats. So what I would like to do is post, then retrieve the last post using the getNetworkUpdates() function, and in that retrieval will be the UpdateKey that I need to use later to retrieve stats. Here's a sample script in Java on how to get network updates, but I need to do this in Coldfusion instead of Java.
Network network = client.getNetworkUpdates(EnumSet.of(NetworkUpdateType.STATUS_UPDATE));
System.out.println("Total updates fetched:" + network.getUpdates().getTotal());
for (Update update : network.getUpdates().getUpdateList()) {
System.out.println("-------------------------------");
System.out.println(update.getUpdateKey() + ":" + update.getUpdateContent().getPerson().getFirstName() + " " + update.getUpdateContent().getPerson().getLastName() + "->" + update.getUpdateContent().getPerson().getCurrentStatus());
if (update.getUpdateComments() != null) {
System.out.println("Total comments fetched:" + update.getUpdateComments().getTotal());
for (UpdateComment comment : update.getUpdateComments().getUpdateCommentList()) {
System.out.println(comment.getPerson().getFirstName() + " " + comment.getPerson().getLastName() + "->" + comment.getComment());
}
}
}
Anyone have any thoughts on how to accomplish this using Coldfusion?
Thanks

I have not used that api, but I am guessing you could use the first two lines to grab the number of updates. Then use the overloaded client.getNetworkUpdates(start, end) method to retrieve the last update and obtain its key.
Totally untested, but something along these lines:
<cfscript>
...
// not sure about accessing the STATUS_UPDATE enum. One of these should work:
// method 1
STATUS_UPDATE = createObject("java", "com.google.code.linkedinapi.client.enumeration.NetworkUpdateType$STATUS_UPDATE");
// method 2
NetworkUpdateType = createObject("java", "com.google.code.linkedinapi.client.enumeration.NetworkUpdateType");
STATUS_UPDATE = NetworkUpdateType.valueOf("STATUS_UPDATE");
enumSet = createObject("java", "java.util.EnumSet");
network = yourClientObject.getNetworkUpdates(enumSet.of(STATUS_UPDATE));
numOfUpdates = network.getUpdates().getTotal();
// Add error handling in case numOfUpdates = 0
result = yourClientObject.getNetworkUpdates(numOfUpdates, numOfUpdates);
lastUpdate = result.getUpdates().getUpdateList().get(0);
key = lastUpdate.getUpdateKey();
</cfscript>

You can also use socialauth library to retrieve updates and post status on linkedin.
http://code.google.com/p/socialauth