Question2:
I'm confused on ArrayList<Object>, please explain to me the following:
I have a class Node which has two fields: data1 and data2
public class Node {
private static int data1;
private static int data2;
public Node(){...}
public static void setData1(int data);
public static void getData1();
public static void setData2(int data);
public static void getData2();
} // end of class Node
And then I have another class called Link.
public class Link {
private ArrayList<Node> linkList = new ArrayList<Node>();
private Node node = new Node();
...
linkList.add(node)
linkList.get(how to do it here)
} // end of class Link
I want to output the Node data inside linkList.
linkList.get(how to do it here)
How would I do that?
I think you simply forgot to do something like
private ArrayList<node> linkList = new ArrayList<node>();
Try:
public class Link {
private ArrayList<node> linkList = new ArrayList<node>();
private node nodelist = new node();
...
linkList.add(nodelist)
} // end of class link
EDIT
Take a look to the following sample code taken from here to understand how to work with ArrayList<...>
java.util.ArrayList<String> v = new java.util.ArrayList<String>();
v.add( "able" );
v.add( "baker" );
v.add( "charlie" );
v.add( "delta" );
int n = v.size();
for(int i = 0; i < n ; i++)
System.out.println( v.get( i ) );
OP solved it by using:
linkList.get(0).getData();
Related
I dont know why but Im always getting NullPointer and no idea why and how exactly this test should looks like. Its about method: webServiceTemplate():
#Configuration
public class ErdConfiguration {
#Autowired
private EJwtProperties eJwtProperties;
public Jaxb2Marshaller marshaller() {
Jaxb2Marshaller marshaller = new Jaxb2Marshaller();
// this package must match the package in the <generatePackage> specified in pom.xml
marshaller.setContextPath("erdUserRoles.wsdl");
return marshaller;
}
public WebServiceTemplate webServiceTemplate() {
WebServiceTemplate webServiceTemplate = new WebServiceTemplate();
webServiceTemplate.setMarshaller(marshaller());
webServiceTemplate.setUnmarshaller(marshaller());
webServiceTemplate.setDefaultUri(eJwtProperties.getRoles().getErdServiceUri());
return webServiceTemplate;
}
}
and EJwtProperties class which it uses:
public class EJwtProperties {
private Map<String, String> claims = new HashMap<>();
private String signingKey;
private SourceTokenConfig sourceToken = new SourceTokenConfig();
private RolesConfig roles = new RolesConfig();
private List<String> generateEjwtRoles = Collections.emptyList();
private boolean cacheDisabled = false;
#Data
public static class SourceTokenConfig {
private boolean embedSourceToken = false;
private String embeddedTokenClaimName = "source-token";
}
#Data
public static class RolesConfig {
private boolean rolesEnabled = false;
private String rolesClaimName = "roles";
private String erdAppId;
private String erdServiceUri;
}
}
My code so far looks like this and got null pointer while Im trying to check getRoles() in when-thenReturn :
#Mock
private EJwtProperties eJwtProperties;
#InjectMocks
private ErdConfiguration underTest;
Jaxb2Marshaller marshaller;
#BeforeEach
void setUp() {
MockitoAnnotations.openMocks(this);
}
#Test
void webServiceTemplateTest() {
EJwtProperties.RolesConfig roles = new EJwtProperties.RolesConfig();
roles.setErdServiceUri("testErdServiceUri");
eJwtProperties.setRoles(roles);
underTest = new ErdConfiguration();
when(eJwtProperties.getRoles()).thenReturn(roles); //this one passed
when(eJwtProperties.getRoles().getErdServiceUri()).thenReturn(roles.getErdServiceUri()); //here nullPointer
// underTest.webServiceTemplate(); //this is what I was planning to do next
//assertEquals(underTest.webServiceTemplate(), eJwtProperties.getRoles().getErdServiceUri()); //or this
// assertEquals(marshaller, underTest.webServiceTemplate().getMarshaller());
// assertEquals(marshaller, underTest.webServiceTemplate().getUnmarshaller());
}
}
Please keep in mind that I'm still learning tests. Id be thankful for any help. How the hack it should looks like? What am I missing that it return null ? Should I initialize whole properties??
So I have a class Cycle:
#PlanningEntity
public class Cycle {
private Integer START = 29;
private Integer END = 42;
private final int SUSTAIN_START = 29;
private final int SUSTAIN_END = 72;
#PlanningVariable(valueRangeProviderRefs = { "startRange" } )
public Integer getStartIndex() {
System.out.println("DEBUG: getStartIndex");
return START;
}
public void setStartIndex(Integer i) {
System.out.println("DEBUG: setStartIndex");
START = i;
END = i+13;
}
#ValueRangeProvider(id = "startRange")
public List<Integer> getStartIndexes () {
ArrayList<Integer> startRange = new ArrayList<Integer>();
for(int i = SUSTAIN_START; i < SUSTAIN_END; i++) {
startRange.add(i);
}
return startRange;
}
}
and Optplanner doesn't ever call any of these methods, and I have no clue why. I've tried adding a "#ProblemFactCollectionProperty" annotatation on the getStartIndexes method, but I read in the docs that that annotation should only be used within a PlanningSolution.
I've also tried using scanAnnotatedClasses and explicitly specifying the entityClass in my solver config and neither seemed to make a difference.
Why can't Optaplanner see my variable and why doesn't Optaplanner change it?
More Info: I'm using Optaplanner version 7.30.0.Final and I have another planning entity with two planning variables that are seen and changed by Optaplanner.
The problem, per #yurloc's comment, was that I was missing the PlanningEntityCollectionProperty for Cycles in my PlanningSolution class. Thanks for the help!
I try to use foreign collections in ORMLite. However, I dont know how to convert it into list. I try to do something like this :
public class Car implements Serializable {
#DatabaseField(columnName = "carId" , generatedId = true, id=true)
private int id;
#DatabaseField(columnName = "carNumber")
private String mNumber;
#DatabaseField(columnName = "carName")
private String mName;
#ForeignCollectionField(eager = true,columnName = "carParts")
private Collection<Part> mParts;
ArrayList<Part> parts = new ArrayList<>(mParts);
public ArrayList<Part> getParts() {
return parts;
}
public void setParts(ArrayList<Part> parts) {
this.parts = parts;
}
but when I try to use it I get exception :
java.lang.NullPointerException: collection == null
at this line :
ArrayList<Part> parts = new ArrayList<>(mParts);
please, help.
The reason is simple - you have to wait until mParts will be initialized by ORMLite library, then you can create ArrayList from it.
public ArrayList<Part> getParts() {
return new ArrayList<>( mParts );
}
This is a project I am working on and it is supposed to take input from the user then which is an area code then see if it is contained in a array list. My method that I have created will not work in another class and I am not sure why, it is returning a NullPointerException.
The NullPointerException is shown at this line of code: if (mountainTime.contains(input))
This is the class with methods
package finalPro;
import java.util.ArrayList;
public class Final
{
public Final()
{
input = 0;
timezone = 0;
}
public void checkIfTrue(int y)
{
input = y;
if (mountainTime.contains(input))
{
timezone = 1;
}
else
timezone = 0;
System.out.println(timezone);
}
public int getZone()
{
return timezone;
}
public ArrayList<Integer> mountainTime;
private int input;
private int timezone;
}
Here is test class
package finalPro;
import java.util.ArrayList;
import javax.swing.JOptionPane;
public class FinalLogic
{
public static void main(String[] args)
{
ArrayList<Integer> mountainTime = new ArrayList<Integer>();
mountainTime.add(480);
mountainTime.add(602);
mountainTime.add(623); //Arizona area codes
mountainTime.add(928);
mountainTime.add(520);
mountainTime.add(303);
mountainTime.add(719); //Colorado
mountainTime.add(720);
mountainTime.add(970);
mountainTime.add(406); //Montana
mountainTime.add(505); //New Mexico
mountainTime.add(575);
mountainTime.add(385);
mountainTime.add(435); //Utah
mountainTime.add(801);
mountainTime.add(307); //Wyoming
Final myMap = new Final();
{
String x = JOptionPane.showInputDialog("Please enter a number: ");
int input = Integer.parseInt(x);
myMap.checkIfTrue(input);
}
}
}
I hope it's not too late, I haven't done anything special to fix your code, just some movement of code,
Removed the initialization logic from class FinalLogic to Final class .(btw Final name is not really good, you might be aware final is reserved word in Java. Although your name is case sensitive but still)
package finalPro;
import javax.swing.JOptionPane;
public class FinalLogic {
public static void main(String[] args) {
Final myMap = new Final();
String x = JOptionPane.showInputDialog("Please enter a number: ");
int input = Integer.parseInt(x);
myMap.checkIfTrue(input);
}
}
And here is your class Final
package finalPro;
import java.util.ArrayList;
public class Final {
public Final() {
input = 0;
timezone = 0;
// moved all initialization logic to constructor
mountainTime = new ArrayList<>();
mountainTime.add(480);
mountainTime.add(602);
mountainTime.add(623); // Arizona area codes
mountainTime.add(928);
mountainTime.add(520);
mountainTime.add(303);
mountainTime.add(719); // Colorado
mountainTime.add(720);
mountainTime.add(970);
mountainTime.add(406); // Montana
mountainTime.add(505); // New Mexico
mountainTime.add(575);
mountainTime.add(385);
mountainTime.add(435); // Utah
mountainTime.add(801);
mountainTime.add(307); // Wyoming
}
public void checkIfTrue(int y) {
input = y;
if (mountainTime.contains(input)) {
timezone = 1;
} else
timezone = 0;
System.out.println(timezone);
}
public int getZone() {
return timezone;
}
public ArrayList<Integer> mountainTime;
private int input;
private int timezone;
}
I tried in my workspace, it gives no NPE, Hope it helps.
We are using fluentnhibernate with automapping and we have a naming convention that all columns that are foreign keys, there column name will end with "Key". So we have a convention that looks like this:
public class ForeignKeyColumnNameConvention : IReferenceConvention
{
public void Apply ( IManyToOneInstance instance )
{
// name the key field
string propertyName = instance.Property.Name;
instance.Column ( propertyName + "Key" );
}
}
This works great until we created a component in which one of its values is a foreign key. By renaming the column here it overrides the default name given to the component column which includes the ComponentPrefix which is defined in the AutomappingConfiguration. Is there a way for me to get the ComponentPrefix in this convention? or is there some other way for me to get the column name for components with a property that is a foreign key to end in the word "Key"?
After a lot of fiddling and trial & error (thus being tempted to use your solution with Reflection) I came up with the following:
This method depends on the order of the execution of the conventions. This convention-order happens via a strict hierarchy. In this example, at first, the convention of the component (IDynamicComponentConvention) is being handled and after that the conventions of the inner properties are being handled such as the References mapping (IReferenceConvention).
The strict order is where we make our strike:
We assemble the correct name of the column in the call to Apply(IDynamicComponentConvention instance), put it on the queue. Note that a Queue<T> is used which is a FIFO (first-in-first-out) collection type thus it keeps the order correctly.
Almost immediately after that, Apply(IManyToOneInstanceinstance) is called. We check if there is anything in the queue. If there is, we take it out of the queue and set it as column name. Note that you should not use Peek() instead of Dequeue() as it does not remove the object from the queue.
The code is as follows:
public sealed class CustomNamingConvention : IDynamicComponentConvention, IReferenceConvention {
private static Queue<string> ColumnNames = new Queue<string>();
public void Apply(IDynamicComponentInstance instance) {
foreach (var referenceInspector in instance.References) {
// All the information we need is right here
// But only to inspect, no editing yet :(
// Don't worry, just assemble the name and enqueue it
var name = string.Format("{0}_{1}",
instance.Name,
referenceInspector.Columns.Single().Name);
ColumnNames.Enqueue(name);
}
}
public void Apply(IManyToOneInstance instance) {
if (!ColumnNames.Any())
// Nothing in the queue? Just return then (^_^)
return;
// Set the retrieved string as the column name
var columnName = ColumnNames.Dequeue();
instance.Column(columnName);
// Pick a beer and celebrate the correct naming!
}
}
I Have figured out a way to do this using reflection to get to the underlying mapping of the IManyToOneInspector exposed by the IComponentInstance but was hoping there was a better way to do this?
Here is some example code of how I achieved this:
#region IConvention<IComponentInspector, IComponentInstance> Members
public void Apply(IComponentInstance instance)
{
foreach (var manyToOneInspector in instance.References)
{
var referenceName = string.Format("{0}_{1}_{2}{3}", instance.EntityType.Name, manyToOneInspector.Property.PropertyType.Name, _autoMappingConfiguration.GetComponentColumnPrefix(instance.Property), manyToOneInspector.Property.Name);
if(manyToOneInspector.Property.PropertyType.IsSubclassOf(typeof(LookupBase)))
{
referenceName += "Lkp";
}
manyToOneInspector.Index ( string.Format ( "{0}_FK_IDX", referenceName ) );
}
}
#endregion
public static class ManyToOneInspectorExtensions
{
public static ManyToOneMapping GetMapping(this IManyToOneInspector manyToOneInspector)
{
var fieldInfo = manyToOneInspector.GetType ().GetField( "mapping", BindingFlags.NonPublic | BindingFlags.Instance );
if (fieldInfo != null)
{
var manyToOneMapping = fieldInfo.GetValue( manyToOneInspector ) as ManyToOneMapping;
return manyToOneMapping;
}
return null;
}
public static void Index(this IManyToOneInspector manyToOneInspector, string indexName)
{
var mapping = manyToOneInspector.GetMapping ();
mapping.Index ( indexName );
}
public static void Column(this IManyToOneInspector manyToOneInspector, string columnName)
{
var mapping = manyToOneInspector.GetMapping ();
mapping.Column ( columnName );
}
public static void ForeignKey(this IManyToOneInspector manyToOneInspector, string foreignKeyName)
{
var mapping = manyToOneInspector.GetMapping();
mapping.ForeignKey ( foreignKeyName );
}
}
public static class ManyToOneMappingExtensions
{
public static void Index (this ManyToOneMapping manyToOneMapping, string indexName)
{
if (manyToOneMapping.Columns.First().IsSpecified("Index"))
return;
foreach (var column in manyToOneMapping.Columns)
{
column.Index = indexName;
}
}
public static void Column(this ManyToOneMapping manyToOneMapping, string columnName)
{
if (manyToOneMapping.Columns.UserDefined.Count() > 0)
return;
var originalColumn = manyToOneMapping.Columns.FirstOrDefault();
var column = originalColumn == null ? new ColumnMapping() : originalColumn.Clone();
column.Name = columnName;
manyToOneMapping.ClearColumns();
manyToOneMapping.AddColumn(column);
}
public static void ForeignKey(this ManyToOneMapping manyToOneMapping, string foreignKeyName)
{
if (!manyToOneMapping.IsSpecified("ForeignKey"))
manyToOneMapping.ForeignKey = foreignKeyName;
}
}