Develop Reference

Get all Snapshots for a Machine (VirtualBox Java API)

I'm using the Java API for VirtualBox from the SDK version "VirtualBoxSDK-5.1.22-115126" (vboxjws.jar).
I want to get a List of all snapshots belonging to the IMachine object (object representing one virtual machine) that I'm working with.
IMachine has the method findSnapshot(String nameOrId) which returns a snapshot for the given name or UUID. But I want a list of ALL snapshots the machine has...
The command line interface vboxmanage is able to return a list of all snapshots with the command:
vboxmanage snapshot <uuid|vmname> list
(source: https://www.virtualbox.org/manual/ch08.html#idm4900)
So is this method missing in the API by design or have the developers from Oracle just forgotten to implement it? (would proof that they are just human beings too ;))

Snapshots is a tree structure with a root snapshot, from which all other snapshots originate. You could say it is by design the API call does not exists, but you can implement it yourself directly by going through the tree.
This sample will do just that:
import org.virtualbox_5_1.IMachine;
import org.virtualbox_5_1.ISnapshot;
import org.virtualbox_5_1.IVirtualBox;
import org.virtualbox_5_1.VirtualBoxManager;
public class SnapshotList {
private static void printChilds(ISnapshot snapshot) {
System.out.println("\"" + snapshot.getName() + "\" {" + snapshot.getId() + "}");
for (ISnapshot snapChild : snapshot.getChildren()) {
printChilds(snapChild);
}
}
public static void main(String[] args) {
/*
* WebServices info
*/
String wsHost = "http://localhost:18083";
String wsUser = "user";
String wsPass = "password";
if (args.length < 1 || args[0] == null || args[0].length() < 1) {
System.err.println("Specify the VM name/UUID as first parameter");
System.exit(1);
}
String vmName = args[0];
VirtualBoxManager vboxManager = VirtualBoxManager.createInstance(null);
vboxManager.connect(wsHost, wsUser, wsPass);
try {
IVirtualBox vbox = vboxManager.getVBox();
IMachine vm = vbox.findMachine(vmName);
if (vm.getSnapshotCount() < 1) {
System.out.println("The machine + " + vmName + " has no snapshot");
System.exit(0);
}
// The magic is here: null will give you the root snapshot
printChilds(vm.findSnapshot(null));
} finally {
vboxManager.disconnect();
vboxManager.cleanup();
}
}
}
I assume you know how to configure the WS login & password variables or disable authentication on the WebService process.
The doc of IMachine::findSnapshot() explains that null can be used to fetch the root snapshot, from which you can just process the childs:
Returns a snapshot of this machine with the given UUID. A null
argument can be used to obtain the first snapshot taken on this
machine. To traverse the whole tree of snapshots starting from the
root, inspect the root snapshot's ISnapshot::children attribute and
recurse over those children.

Flexible search with parameters return null value

I have to do this flexible search query in a service Java class:
select sum({oe:totalPrice})
from {Order as or join CustomerOrderStatus as os on {or:CustomerOrderStatus}={os:pk}
join OrderEntry as oe on {or.pk}={oe.order}}
where {or:versionID} is null and {or:orderType} in (8796093066999)
and {or:company} in (8796093710341)
and {or:pointOfSale} in (8796097413125)
and {oe:ecCode} in ('13','14')
and {or:yearSeason} in (8796093066981)
and {os:code} not in ('CANCELED', 'NOT_APPROVED')
When I perform this query in the hybris administration console I correctly obtain:
1164.00000000
In my Java service class I wrote this:
private BigDecimal findGroupedOrdersData(String total, String uncDisc, String orderPromo,
Map<String, Object> queryParameters) {
BigDecimal aggregatedValue = new BigDecimal(0);
final StringBuilder queryBuilder = new StringBuilder();
queryBuilder.append("select sum({oe:").append(total).append("})");
queryBuilder.append(
" from {Order as or join CustomerOrderStatus as os on {or:CustomerOrderStatus}={os:pk} join OrderEntry as oe on {or.pk}={oe.order}}");
queryBuilder.append(" where {or:versionID} is null");
if (queryParameters != null && !queryParameters.isEmpty()) {
appendWhereClausesToBuilder(queryBuilder, queryParameters);
}
queryBuilder.append(" and {os:code} not in ('");
queryBuilder.append(CustomerOrderStatus.CANCELED.getCode()).append("', ");
queryBuilder.append("'").append(CustomerOrderStatus.NOT_APPROVED.getCode()).append("')");
FlexibleSearchQuery query = new FlexibleSearchQuery(queryBuilder.toString(), queryParameters);
List<BigDecimal> result = Lists.newArrayList();
query.setResultClassList(Arrays.asList(BigDecimal.class));
result = getFlexibleSearchService().<BigDecimal> search(query).getResult();
if (!result.isEmpty() && result.get(0) != null) {
aggregatedValue = result.get(0);
}
return aggregatedValue;
}
private void appendWhereClausesToBuilder(StringBuilder builder, Map<String, Object> params) {
if ((params == null) || (params.isEmpty()))
return;
for (String paramName : params.keySet()) {
builder.append(" and ");
if (paramName.equalsIgnoreCase("exitCollection")) {
builder.append("{oe:ecCode}").append(" in (?").append(paramName).append(")");
} else {
builder.append("{or:").append(paramName).append("}").append(" in (?").append(paramName).append(")");
}
}
}
The query string before the search(query).getResult() function is:
query: [select sum({oe:totalPrice}) from {Order as or join CustomerOrderStatus as os on {or:CustomerOrderStatus}={os:pk}
join OrderEntry as oe on {or.pk}={oe.order}} where {or:versionID} is null
and {or:orderType} in (?orderType) and {or:company} in (?company)
and {or:pointOfSale} in (?pointOfSale) and {oe:ecCode} in (?exitCollection)
and {or:yearSeason} in (?yearSeason) and {os:code} not in ('CANCELED', 'NOT_APPROVED')],
query parameters: [{orderType=OrderTypeModel (8796093230839),
pointOfSale=B2BUnitModel (8796097413125), company=CompanyModel (8796093710341),
exitCollection=[13, 14], yearSeason=YearSeasonModel (8796093066981)}]
but after the search(query) result is [null].
Why? Where I wrong in the Java code? Thanks.

In addition, if you want to disable restriction in your java code. You can do like this ..
#Autowired
private SearchRestrictionService searchRestrictionService;
private BigDecimal findGroupedOrdersData(String total, String uncDisc, String orderPromo,
Map<String, Object> queryParameters) {
searchRestrictionService.disableSearchRestrictions();
// You code here
searchRestrictionService.enableSearchRestrictions();
return aggregatedValue;
}
In the above code, You can disabled the search restriction and after the search result, you can again enable it.
OR
You can use sessionService to execute flexible search query in Local View. The method executeInLocalView can be used to execute code within an isolated session.
(SearchResult<? extends ItemModel>) sessionService.executeInLocalView(new SessionExecutionBody()
{
#Override
public Object execute()
{
sessionService.setAttribute(FlexibleSearch.DISABLE_RESTRICTIONS, Boolean.TRUE);
return flexibleSearchService.search(query);
}
});
Here you are setting DISABLE RESTRICTIONS = true which will run the query in admin context [Without Restriction].
Check this
Better i would suggest you to check what restriction exactly applying to your item type. You can simply check in Backoffice/HMC
Backoffice :
Go to System-> Personalization (SearchRestricion)
Search by Restricted Type
Check Filter Query and analysis your item data based on that.
You can also check its Principal (UserGroup) on which restriction applied.
To confirm, just check by disabling active flag.

Query in the code is running not under admin user (most likely).
And in this case the different search Restrictions are applied to the query.
You can see that the original query is changed:
start DB logging (/hac -> Monitoring -> Database -> JDBC logging);
run the query from the code;
stop DB logging and check log file.
More information: https://wiki.hybris.com/display/release5/Restrictions
In /hac console the admin user is usually used and restrictions will not be applied because of this.

As the statement looks ok to me i'm going to go with visibility of the data. Are you able to see all the items as whatever user you are running the query as? In the hac you would be admin obviously.

Using a Commonj Work Manager to send Asynchronous HTTP calls

I switched from making sequential HTTP calls to 4 REST services, to making 4 simultaneous calls using a commonj4 work manager task executor. I'm using WebLogic 12c. This new code works on my development environment, but in our test environment under load conditions, and occasionally while not under load, the results map is not populated with all of the results. The logging suggests that each work item did receive back the results though. Could this be a problem with the ConcurrentHashMap? In this example from IBM, they use their own version of Work and there's a getData() method, although it doesn't like that method really exists in their class definition. I had followed a different example that just used the Work class but didn't demonstrate how to get the data out of those threads into the main thread. Should I be using execute() instead of schedule()? The API doesn't appear to be well documented. The stuckthreadtimeout is sufficiently high. component.processInbound() actually contains the code for the HTTP call, but I the problem isn't there because I can switch back to the synchronous version of the class below and not have any issues.
http://publib.boulder.ibm.com/infocenter/wsdoc400/v6r0/index.jsp?topic=/com.ibm.websphere.iseries.doc/info/ae/asyncbns/concepts/casb_workmgr.html
My code:
public class WorkManagerAsyncLinkedComponentRouter implements
MessageDispatcher<Object, Object> {
private List<Component<Object, Object>> components;
protected ConcurrentHashMap<String, Object> workItemsResultsMap;
protected ConcurrentHashMap<String, Exception> componentExceptionsInThreads;
...
//components is populated at this point with one component for each REST call to be made.
public Object route(final Object message) throws RouterException {
...
try {
workItemsResultsMap = new ConcurrentHashMap<String, Object>();
componentExceptionsInThreads = new ConcurrentHashMap<String, Exception>();
final String parentThreadID = Thread.currentThread().getName();
List<WorkItem> producerWorkItems = new ArrayList<WorkItem>();
for (final Component<Object, Object> component : this.components) {
producerWorkItems.add(workManagerTaskExecutor.schedule(new Work() {
public void run() {
//ExecuteThread th = (ExecuteThread) Thread.currentThread();
//th.setName(component.getName());
LOG.info("Child thread " + Thread.currentThread().getName() +" Parent thread: " + parentThreadID + " Executing work item for: " + component.getName());
try {
Object returnObj = component.processInbound(message);
if (returnObj == null)
LOG.info("Object returned to work item is null, not adding to producer components results map, for this producer: "
+ component.getName());
else {
LOG.info("Added producer component thread result for: "
+ component.getName());
workItemsResultsMap.put(component.getName(), returnObj);
}
LOG.info("Finished executing work item for: " + component.getName());
} catch (Exception e) {
componentExceptionsInThreads.put(component.getName(), e);
}
}
...
}));
} // end loop over producer components
// Block until all items are done
workManagerTaskExecutor.waitForAll(producerWorkItems, stuckThreadTimeout);
LOG.info("Finished waiting for all producer component threads.");
if (componentExceptionsInThreads != null
&& componentExceptionsInThreads.size() > 0) {
...
}
List<Object> resultsList = new ArrayList<Object>(workItemsResultsMap.values());
if (resultsList.size() == 0)
throw new RouterException(
"The producer thread results are all empty. The threads were likely not created. In testing this was observed when either 1)the system was almost out of memory (Perhaps the there is not enough memory to create a new thread for each producer, for this REST request), or 2)Timeouts were reached for all producers.");
//** The problem is identified here. The results in the ConcurrentHashMap aren't the number expected .
if (workItemsResultsMap.size() != this.components.size()) {
StringBuilder sb = new StringBuilder();
for (String str : workItemsResultsMap.keySet()) {
sb.append(str + " ");
}
throw new RouterException(
"Did not receive results from all threads within the thread timeout period. Only retrieved:"
+ sb.toString());
}
LOG.info("Returning " + String.valueOf(resultsList.size()) + " results.");
LOG.debug("List of returned feeds: " + String.valueOf(resultsList));
return resultsList;
}
...
}
}

I ended up cloning the DOM document used as a parameter. There must be some downstream code that has side effects on the parameter.

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

Neo4j ExecutionEngine does not return valid results

Trying to use a similar example from the sample code found here
My sample function is:
void query()
{
String nodeResult = "";
String rows = "";
String resultString;
String columnsString;
System.out.println("In query");
// START SNIPPET: execute
ExecutionEngine engine = new ExecutionEngine( graphDb );
ExecutionResult result;
try ( Transaction ignored = graphDb.beginTx() )
{
result = engine.execute( "start n=node(*) where n.Name =~ '.*79.*' return n, n.Name" );
// END SNIPPET: execute
// START SNIPPET: items
Iterator<Node> n_column = result.columnAs( "n" );
for ( Node node : IteratorUtil.asIterable( n_column ) )
{
// note: we're grabbing the name property from the node,
// not from the n.name in this case.
nodeResult = node + ": " + node.getProperty( "Name" );
System.out.println("In for loop");
System.out.println(nodeResult);
}
// END SNIPPET: items
// START SNIPPET: columns
List<String> columns = result.columns();
// END SNIPPET: columns
// the result is now empty, get a new one
result = engine.execute( "start n=node(*) where n.Name =~ '.*79.*' return n, n.Name" );
// START SNIPPET: rows
for ( Map<String, Object> row : result )
{
for ( Entry<String, Object> column : row.entrySet() )
{
rows += column.getKey() + ": " + column.getValue() + "; ";
System.out.println("nested");
}
rows += "\n";
}
// END SNIPPET: rows
resultString = engine.execute( "start n=node(*) where n.Name =~ '.*79.*' return n.Name" ).dumpToString();
columnsString = columns.toString();
System.out.println(rows);
System.out.println(resultString);
System.out.println(columnsString);
System.out.println("leaving");
}
}
When I run this in the web console I get many results (as there are multiple nodes that have an attribute of Name that contains the pattern 79. Yet running this code returns no results. The debug print statements 'in loop' and 'nested' never print either. Thus this must mean there are not results found in the Iterator, yet that doesn't make sense.
And yes, I already checked and made sure that the graphDb variable is the same as the path for the web console. I have other code earlier that uses the same variable to write to the database.
EDIT - More info
If I place the contents of query in the same function that creates my data, I get the correct results. If I run the query by itself it returns nothing. It's almost as the query works only in the instance where I add the data and not if I come back to the database cold in a separate instance.
EDIT2 -
Here is a snippet of code that shows the bigger context of how it is being called and sharing the same DBHandle
package ContextEngine;
import ContextEngine.NeoHandle;
import java.util.LinkedList;
/*
* Class to handle streaming data from any coded source
*/
public class Streamer {
private NeoHandle myHandle;
private String contextType;
Streamer()
{
}
public void openStream(String contextType)
{
myHandle = new NeoHandle();
myHandle.createDb();
}
public void streamInput(String dataLine)
{
Context context = new Context();
/*
* get database instance
* write to database
* check for errors
* report errors & success
*/
System.out.println(dataLine);
//apply rules to data (make ContextRules do this, send type and string of data)
ContextRules contextRules = new ContextRules();
context = contextRules.processContextRules("Calls", dataLine);
//write data (using linked list from contextRules)
NeoProcessor processor = new NeoProcessor(myHandle);
processor.processContextData(context);
}
public void runQuery()
{
NeoProcessor processor = new NeoProcessor(myHandle);
processor.query();
}
public void closeStream()
{
/*
* close database instance
*/
myHandle.shutDown();
}
}
Now, if I call streamInput AND query in in the same instance (parent calls) the query returns results. If I only call query and do not enter ANY data in that instance (yet web console shows data for same query) I get nothing. Why would I have to create the Nodes and enter them into the database at runtime just to return a valid query. Shouldn't I ALWAYS get the same results with such a query?

You mention that you are using the Neo4j Browser, which comes with Neo4j. However, the example you posted is for Neo4j Embedded, which is the in-process version of Neo4j. Are you sure you are talking to the same database when you try your query in the Browser?
In order to talk to Neo4j Server from Java, I'd recommend looking at the Neo4j JDBC driver, which has good support for connecting to the Neo4j server from Java.
http://www.neo4j.org/develop/tools/jdbc
You can set up a simple connection by adding the Neo4j JDBC jar to your classpath, available here: https://github.com/neo4j-contrib/neo4j-jdbc/releases Then just use Neo4j as any JDBC driver:
Connection conn = DriverManager.getConnection("jdbc:neo4j://localhost:7474/");
ResultSet rs = conn.executeQuery("start n=node({id}) return id(n) as id", map("id", id));
while(rs.next()) {
System.out.println(rs.getLong("id"));
}
Refer to the JDBC documentation for more advanced usage.
To answer your question on why the data is not durably stored, it may be one of many reasons. I would attempt to incrementally scale back the complexity of the code to try and locate the culprit. For instance, until you've found your problem, do these one at a time:
Instead of looping through the result, print it using System.out.println(result.dumpToString());
Instead of the regex query, try just MATCH (n) RETURN n, to return all data in the database
Make sure the data you are seeing in the browser is not "old" data inserted earlier on, but really is an insert from your latest run of the Java program. You can verify this by deleting the data via the browser before running the Java program using MATCH (n) OPTIONAL MATCH (n)-[r]->() DELETE n,r;
Make sure you are actually working against the same database directories. You can verify this by leaving the server running. If you can still start your java program, unless your Java program is using the Neo4j REST Bindings, you are not using the same directory. Two Neo4j databases cannot run against the same database directory simultaneously.