I'm trying to test user defined functions in neo4j 3.1. So I wrote this:
public class Udf
{
#Context
public GraphDatabaseService db;
#Context
public Log log;
#UserFunction("test.id")
public Long id(#Name("node") Node node)
{
return node.getId();
}
}
and a test function like this:
public class UdfTest
{
#Rule
public Neo4jRule neo4j = new Neo4jRule()
.withProcedure(Udf.class);
#Test
public void shouldBeAbleToExtractIdProperty() throws Throwable
{
try (Driver driver = GraphDatabase.driver(neo4j.boltURI() , Config.build().withEncryptionLevel(Config.EncryptionLevel.NONE).toConfig()))
{
Session session = driver.session();
long nodeId = session.run("CREATE (p) RETURN test.id(p)")
.single()
.get(0).asLong();
assertEquals(nodeId, 0);
}
}
}
And when I run the test it prompts:
org.neo4j.driver.v1.exceptions.ClientException: Unknown function 'test.id' (line 1, column 19 (offset: 18))
"CREATE (p) RETURN test.id(p)"
^
When I change the #UserFunction to #Procedure and a bunch of other changes, I can call the exact same method using CALL .. YIELD clause.
Can someone please tell me what I'm doing wrong?
You are using the withProdcedure method instead of the withFunction method on Neo4jRule in your test. Change that line to:
#Rule
public Neo4jRule neo4j = new Neo4jRule()
.withFunction(Udf.class);
Related
I am trying to create extension procedure to Neo4j that will return complex Object (mean object that conation another object).
public static class A {
public final String a;
public A(String a) {
this.a = a;
}
}
public static class Output {
public Object out;
public Output(Object out) {
this.out = out;
}
}
#Procedure(value = "my_proc", mode = Mode.READ)
public Stream<Output> myProc() {
return Stream.of(new Output(new A("a")));
}
When I execute call my_proc(); using Neo4j Browser I it just show the progress circle and never return.
When I execute the same using Java driver, I am getting the following exception:
SEVERE: [0xedd70cbd] Fatal error occurred in the pipeline
org.neo4j.driver.internal.shaded.io.netty.handler.codec.DecoderException: Failed to read inbound message:
at org.neo4j.driver.internal.async.inbound.InboundMessageHandler.channelRead0(InboundMessageHandler.java:87)
at org.neo4j.driver.internal.async.inbound.InboundMessageHandler.channelRead0(InboundMessageHandler.java:35)
....
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:645)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:580)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:497)
at org.neo4j.driver.internal.shaded.io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:459)
at org.neo4j.driver.internal.shaded.io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:858)
at org.neo4j.driver.internal.shaded.io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:138)
at java.lang.Thread.run(Thread.java:748)
Caused by: java.lang.IndexOutOfBoundsException: readerIndex(49) + length(1) exceeds writerIndex(49): PooledDuplicatedByteBuf(ridx: 49, widx: 49, cap: 133, unwrapped: PooledUnsafeDirectByteBuf(ridx: 51, widx: 89, cap: 133))
at org.neo4j.driver.internal.shaded.io.netty.buffer.AbstractByteBuf.checkReadableBytes0(AbstractByteBuf.java:1401)
at org.neo4j.driver.internal.shaded.io.netty.buffer.AbstractByteBuf.readByte(AbstractByteBuf.java:707)
at org.neo4j.driver.internal.async.inbound.ByteBufInput.readByte(ByteBufInput.java:45)
at org.neo4j.driver.internal.packstream.PackStream$Unpacker.unpackLong(PackStream.java:479)
at org.neo4j.driver.internal.messaging.PackStreamMessageFormatV1$Reader.unpackValue(PackStreamMessageFormatV1.java:479)
at org.neo4j.driver.internal.messaging.PackStreamMessageFormatV1$Reader.unpackRecordMessage(PackStreamMessageFormatV1.java:464)
at org.neo4j.driver.internal.messaging.PackStreamMessageFormatV1$Reader.read(PackStreamMessageFormatV1.java:390)
at org.neo4j.driver.internal.async.inbound.InboundMessageHandler.channelRead0(InboundMessageHandler.java:83)
... 39 more
Is there any way to return nested object without serialize it to json before return it?
#Procedure(value = "ebc.neo4j.justamap", mode = Mode.READ)
public Stream<MapResult> justamap() {
HashMap<String, Object> v1Map = new HashMap<String, Object>(1);
HashMap<String, Object> v2Map = new HashMap<String, Object>(1);
v2Map.put("a", "a string");
v1Map.put("map inside", v2Map);
return Stream.of(new MapResult(v1Map));
}
public static class MapResult {
public Map internalmap;
public MapResult(Map aInternalId) {
this.internalmap = aInternalId;
}
}
Something like the above is possible (as deep as you want) but returning custom objects to be used in Cypher (which is the idea when you're writing a procedure) is not going to work as Cypher has no idea what those custom objects are. So you will have to do some sanitizing.
Hope this helps.
Regards,
Tom
this test fails with error and I don't understand why..
I thought that UniqueNodeFactory create node only if it's not exist.
Of course I can do the same using Cypher but I want to understand what happens here..
Could somebody explain?
I am using neo4j 2.3.1.
public class SimpleTest {
private GraphDatabaseService graphService;
#Before
public void setUp() throws Exception {
graphService = new TestGraphDatabaseFactory().newImpermanentDatabase();
graphService.execute("CREATE CONSTRAINT ON (user:User) ASSERT user.userId IS UNIQUE");
}
#After
public void tearDown() throws Exception {
graphService.shutdown();
}
public static UniqueFactory.UniqueNodeFactory createUserFactory(GraphDatabaseService graphDatabaseService) {
return new UniqueFactory.UniqueNodeFactory(graphDatabaseService, "User") {
#Override
protected void initialize(Node created, Map<String, Object> properties) {
created.addLabel(DynamicLabel.label("User"));
created.setProperty("userId", properties.get("userId"));
}
};
}
#Test
public void testCreateUser() throws Exception {
try (Transaction tx = graphService.beginTx()) {
Node node = graphService.createNode(DynamicLabel.label("User"));
node.setProperty("userId", 100L);
tx.success();
}
try (Transaction tx = graphService.beginTx()) {
UniqueFactory.UniqueNodeFactory uniqueFactory = createUserFactory(graphService);
uniqueFactory.getOrCreate("userId", 100L);
tx.success();
}
}
}
error :
Caused by: org.neo4j.kernel.api.exceptions.schema.UniquePropertyConstraintViolationKernelException: Node 0 already exists with label 0 and property 0=100
at org.neo4j.kernel.impl.api.ConstraintEnforcingEntityOperations.validateNoExistingNodeWithLabelAndProperty(ConstraintEnforcingEntityOperations.java:165)
at org.neo4j.kernel.impl.api.ConstraintEnforcingEntityOperations.nodeSetProperty(ConstraintEnforcingEntityOperations.java:140)
at org.neo4j.kernel.impl.api.LockingStatementOperations.nodeSetProperty(LockingStatementOperations.java:453)
at org.neo4j.kernel.impl.api.OperationsFacade.nodeSetProperty(OperationsFacade.java:896)
at org.neo4j.kernel.impl.core.NodeProxy.setProperty(NodeProxy.java:293)
... 33 more
Ok, now I see the reason. I created schema index with Cypher and UniqueNodeFactory use legacy index. To fix the problem you need to create nodes only using UniqueNodeFactory.
So basically, I have a situation where I want to inject primitive types into a class (i.e. a String and an Integer). You can think of a URL and port number for an application as example inputs. I have three components:
Now say I have a class, which does take in these params:
public class PrimitiveParamsDIExample {
private String a;
private Integer b;
public PrimitiveParamsDIExample(String a, Integer b) {
this.a = a;
this.b = b;
}
}
So my question here is simple. How do I inject a and b into class PrimitiveParamsDIExample?
In general, this is also asking how to inject parameters that are decided on runtime as well. If I have a and b above, read from STDIN or from an input file, they're obviously going to be different from run to run.
All the more, how do I do the above within the HK2 framework?
EDIT[02/23/15]: #jwells131313, I tried your idea, but I'm getting the following error (this one for the String param; similar one for int):
org.glassfish.hk2.api.UnsatisfiedDependencyException: There was no object available for injection at Injectee(requiredType=String,parent=PrimitiveParamsDIExample,qualifiers
I set up classes exactly as you did in your answer. I also overrode the toString() method to print both variables a and b in PrimitiveParamsDIExample. Then, I added the following in my Hk2Module class:
public class Hk2Module extends AbstractBinder {
private Properties properties;
public Hk2Module(Properties properties){
this.properties = properties;
}
#Override
protected void configure() {
bindFactory(StringAFactory.class).to(String.class).in(RequestScoped.class);
bindFactory(IntegerBFactory.class).to(Integer.class).in(RequestScoped.class);
bind(PrimitiveParamsDIExample.class).to(PrimitiveParamsDIExample.class).in(Singleton.class);
}
}
So now, I created a test class as follows:
#RunWith(JUnit4.class)
public class TestPrimitiveParamsDIExample extends Hk2Setup {
private PrimitiveParamsDIExample example;
#Before
public void setup() throws IOException {
super.setupHk2();
//example = new PrimitiveParamsDIExample();
example = serviceLocator.getService(PrimitiveParamsDIExample.class);
}
#Test
public void testPrimitiveParamsDI() {
System.out.println(example.toString());
}
}
where, Hk2Setup is as follows:
public class Hk2Setup extends TestCase{
// the name of the resource containing the default configuration properties
private static final String DEFAULT_PROPERTIES = "defaults.properties";
protected Properties config = null;
protected ServiceLocator serviceLocator;
public void setupHk2() throws IOException{
config = new Properties();
Reader defaults = Resources.asCharSource(Resources.getResource(DEFAULT_PROPERTIES), Charsets.UTF_8).openBufferedStream();
load(config, defaults);
ApplicationHandler handler = new ApplicationHandler(new MyMainApplication(config));
final ServiceLocator locator = handler.getServiceLocator();
serviceLocator = locator;
}
private static void load(Properties p, Reader r) throws IOException {
try {
p.load(r);
} finally {
Closeables.close(r, false);
}
}
}
So somewhere, the wiring is messed up for me to get an UnsatisfiedDependencyException. What have I not correctly wired up?
Thanks!
There are two ways to do this, but one isn't documented yet (though it is available... I guess I need to work on documentation again...)
I'll go through the first way here.
Basically, you can use the HK2 Factory.
Generally when you start producing Strings and ints and long and scalars like this you qualify them, so lets start with two qualifiers:
#Retention(RUNTIME)
#Target( { TYPE, METHOD, FIELD, PARAMETER })
#javax.inject.Qualifier
public #interface A {}
and
#Retention(RUNTIME)
#Target( { TYPE, METHOD, FIELD, PARAMETER })
#javax.inject.Qualifier
public #interface B {}
then write your factories:
#Singleton // or whatever scope you want
public class StringAFactory implements Factory<String> {
#PerLookup // or whatever scope, maybe this checks the timestamp?
#A // Your qualifier
public String provide() {
// Write your code to get your value...
return whatever;
}
public void dispose(String instance) {
// Probably do nothing...
}
}
and for the Integer:
#Singleton // or whatever scope you want
public class IntegerBFactory implements Factory<Integer> {
#PerLookup // or whatever scope, maybe this checks the timestamp?
#B // Your qualifier
public Integer provide() {
// Write your code to get your value...
return whatever;
}
public void dispose(String instance) {
// Probably do nothing...
}
}
Now lets re-do your original class to accept these values:
public class PrimitiveParamsDIExample {
private String a;
private int b;
#Inject
public PrimitiveParamsDIExample(#A String a, #B int b) {
this.a = a;
this.b = b;
}
}
Note I changed Integer to int, well... just because I can. You can also just use field injection or method injection in the same way. Here is field injection, method injection is an exercise for the reader:
public class PrimitiveParamsDIExample {
#Inject #A
private String a;
#Inject #B
private int b;
public PrimitiveParamsDIExample() {
}
}
There are several ways to bind factories.
In a binder: bindFactory
Using automatic class analysis: addClasses
An EDSL outside a binder: buildFactory
I am trying to batch together a few cypher queries with the REST API (using the java bindings library) so that only one call is made over the wire. But it seems to not respect the batching on the client side and gives this error:
java.lang.RuntimeException: Error reading as JSON ''
at org.neo4j.rest.graphdb.util.JsonHelper.readJson(JsonHelper.java:57)
at org.neo4j.rest.graphdb.util.JsonHelper.jsonToSingleValue(JsonHelper.java:62)
at org.neo4j.rest.graphdb.RequestResult.toEntity(RequestResult.java:114)
at org.neo4j.rest.graphdb.RequestResult.toMap(RequestResult.java:123)
at org.neo4j.rest.graphdb.batch.RecordingRestRequest.toMap(RecordingRestRequest.java:138)
at org.neo4j.rest.graphdb.ExecutingRestAPI.query(ExecutingRestAPI.java:489)
at org.neo4j.rest.graphdb.ExecutingRestAPI.query(ExecutingRestAPI.java:509)
at org.neo4j.rest.graphdb.RestAPIFacade.query(RestAPIFacade.java:233)
at org.neo4j.rest.graphdb.query.RestCypherQueryEngine.query(RestCypherQueryEngine.java:50)
...
Caused by: java.io.EOFException: No content to map to Object due to end of input
at org.codehaus.jackson.map.ObjectMapper._initForReading(ObjectMapper.java:2766)
at org.codehaus.jackson.map.ObjectMapper._readMapAndClose(ObjectMapper.java:2709)
at org.codehaus.jackson.map.ObjectMapper.readValue(ObjectMapper.java:1854)
at org.neo4j.rest.graphdb.util.JsonHelper.readJson(JsonHelper.java:55)
... 41 more
This is how I am trying to batch them:
graphDatabaseService.getRestAPI().executeBatch(new BatchCallback<Void>() {
#Override
public Void recordBatch(RestAPI batchRestApi) {
String query = "CREATE accounts=({userId:{userId}})-[r:OWNS]->({facebookId:{facebookId}})";
graphDatabaseService.getQueryEngine().query(query, map("userId", 1, "facebookId", "1"));
graphDatabaseService.getQueryEngine().query(query, map("userId", 2, "facebookId", "2"));
graphDatabaseService.getQueryEngine().query(query, map("userId", 3, "facebookId", "3"));
return null;
}
});
I am using noe4j version 1.9 and the corresponding client library. Should this be possible?
Here is a JUnit sample code that works for your batch. Here no string template is used but native methods on the RestAPI object:
public static final DynamicRelationshipType OWNS = DynamicRelationshipType.withName("OWNS");
#Autowired
private SpringRestGraphDatabase graphDatabaseService;
#Test
public void batchTest()
{
Assert.assertNotNull(this.graphDatabaseService);
this.graphDatabaseService.getRestAPI().executeBatch(new BatchCallback<Void>()
{
#Override
public Void recordBatch(RestAPI batchRestApi)
{
for (int counter = 1; counter <= 3; counter++)
{
RestNode userId = batchRestApi.createNode(map("userId", Integer.valueOf(counter)));
RestNode facebookId = batchRestApi.createNode(map("facebookId", Integer.valueOf(counter).toString()));
batchRestApi.createRelationship(userId, facebookId, OWNS, map());
}
return null;
}
});
}
I have a problem about the mbeans. I have created a simple mbean and I have registered it on the default mBeanServer that is run (Via eclipse or java -jar mbean.jar) and in the same process if I try to fouund the mbean registered with a simple query:
for (ObjectInstance instance : mbs.queryMBeans(ObjectNameMbean, null)) {
System.out.println(instance.toString());
}
the query retuerns my mbean, but if I start another process and try to search this mbean registered the mbeas is not found! why?
The approch is : (Process that is running)
public static void main(String[] args) throws Exception
{
MBeanServer mbeanServer =ManagementFactory.getPlatformMBeanServer();
ObjectName objectName = new ObjectName(ObjectNameMbean);
Simple simple = new Simple (1, 0);
mbeanServer.registerMBean(simple, objectName);
while (true)
{
wait (Is this necessary?)
}
}
So this is the first process that is running (that has the only pourpose to registry the mbean, because there is another process that want to read these informations.
So I start another process to search this mbean but nothing.
I 'm not using jboss but the local Java virtual Machine but my scope is to deploy this simple application in one ejb (autostart) and another ejb will read all informations.
All suggestions are really apprecciated.
This example should be more useful :
Object Hello:
public class Hello implements HelloMBean {
public void sayHello() {
System.out.println("hello, world");
}
public int add(int x, int y) {
return x + y;
}
public String getName() {
return this.name;
}
public int getCacheSize() {
return this.cacheSize;
}
public synchronized void setCacheSize(int size) {
this.cacheSize = size;
System.out.println("Cache size now " + this.cacheSize);
}
private final String name = "Reginald";
private int cacheSize = DEFAULT_CACHE_SIZE;
private static final int DEFAULT_CACHE_SIZE = 200;
}
Interface HelloBean (implemented by Hello)
public interface HelloMBean {
public void sayHello();
public int add(int x, int y);
public String getName();
public int getCacheSize();
public void setCacheSize(int size);
}
Simple Main
import java.lang.management.ManagementFactory;
import java.util.logging.Logger;
import javax.management.MBeanServer;
import javax.management.ObjectName;
public class Main {
static Logger aLog = Logger.getLogger("MBeanTest");
public static void main(String[] args) {
try{
MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
ObjectName name = new ObjectName("ApplicationDomain:type=Hello");
Hello mbean = new Hello();
mbs.registerMBean(mbean, name);
// System.out.println(mbs.getAttribute(name, "Name"));
aLog.info("Waiting forever...");
Thread.sleep(Long.MAX_VALUE);
}
catch(Exception x){
x.printStackTrace();
aLog.info("exception");
}
}
}
So now I have exported this project as jar file and run it as "java -jar helloBean.jar" and by eclipse I have modified the main class to read informations of this read (Example "Name" attribute) by using the same objectname used to registry it .
Main to read :
public static void main(String[] args) {
try{
MBeanServer mbs = ManagementFactory.getPlatformMBeanServer();
ObjectName name = new ObjectName("ApplicationDomain:type=Hello");
System.out.println(mbs.getAttribute(name, "Name"));
}
catch(Exception x){
x.printStackTrace();
aLog.info("exception");
}
}
But nothing, the bean is not found.
Project link : here!
Any idea?
I suspect the issue here is that you have multiple MBeanServer instances. You did not mention how you acquired the MBeanServer in each case, but in your second code sample, you are creating a new MBeanServer instance which may not be the same instance that other threads are reading from. (I assume this is all in one JVM...)
If you are using the platform agent, I recommend you acquire the MBeanServer using the ManagementFactory as follows:
MBeanServer mbs = java.lang.management.ManagementFactory.getPlatformMBeanServer() ;
That way, you will always get the same MBeanServer instance.