Assert key in hashmap JUnit - junit

I thought it was going to be easy but can anyone tell me how I can test HashMap to see if it has some value in JUnit?
assertThat(myMap, ??);
I tried something like:
assertThat(myMap, hasEntry("Key", notNullValue()));
...But I couldn't make it compile since my import to hasEntry and notNullValue() is correct.
Does anyone know what the correct import pkg for them should be?

You're after hasEntry(Matcher<? super K> keyMatcher, Matcher<? super V> valueMatcher).
The underlying implementation is in IsMapContaining but,
like most matchers in Hamcrest, it can also be found through org.hamcrest.Matchers, in hamcrest-library.
Otherwise, your syntax is correct, and Matchers also defines notNullValue().

import static org.junit.Assert.AssertTrue;
assertTrue(myMap.containsKey("yourKey") && myMap.get("yourKey") != null)

To check the key is in the map:
import static org.junit.Assert.assertTrue;
...
assertTrue(myMap.containsKey("Key"));
Alternatively, to check it has a non-null value:
import static org.junit.Assert.assertNotNull;
...
assertNotNull(myMap.get("Key"));

I don't like the assertTrue approaches, because the feedback is quite limited when the assertion fails.
It can be done with assertThat like this:
import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.Matchers.hasEntry;
import static org.hamcrest.Matchers.is;
import static org.hamcrest.Matchers.notNullValue;
assertThat(myMap, hasEntry(is("Key"), notNullValue()));

Related

Can't write to a csv file from a class in kotlin

Im trying to write a class to csv. And I need or at least prefer a class that I could call that could both retrieve and eventually save the class objects as csv.
I have tried every imaginable way I can find to write files. Everytime it works flawlessly in the main activity .kt, but soon as I move any of it to a dedicated class I get:
java.lang.NullPointerException: Attempt to invoke virtual method 'java.io.FileOutputStream android.content.Context.openFileOutput(java.lang.String, int)' on a null object reference
or I get told thats is a read only file system.
Heres a copy of a class that ive tried and gotten the error.
package com.example.jobndays
import android.content.Context
import androidx.appcompat.app.AppCompatActivity
import java.io.File
import java.io.FileInputStream
import java.io.FileOutputStream
import java.io.PrintWriter
class DryTest: AppCompatActivity() {
fun main() {
var fileInputStream: FileOutputStream? = null
fileInputStream = openFileOutput("bobbin.csv", MODE_PRIVATE)
val bob = "fella"
fileInputStream.write(bob.toByteArray())
}
}
I believe I've found an answer. Apparently in order to write files you need 'context', not entirely sure why, but just ask for it and stick infront of stuff that says they're unresolved.

How to defiine class variable not importing package with it?

for example is it possible to do somehing like public var socket:flash.net.Socket = new flash.net.Socket();?
No you will still get a class undefined compiler error if you don't import flash.net.Socket

No exception of type DataAccessException can be thrown; an exception type must be a subclass of Throwable

My source code like below.
It has a error, "No exception of type DataAccessException can be thrown; an exception type must be a subclass of Throwable".
I can't understand why the error ocurrs.
let me know. thx.
package com.sds.afi.cosmos.cmm.db.impl;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.List;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.dao.DataAccessException;
import org.springframework.orm.ibatis.SqlMapClientTemplate;
import org.springframework.orm.ibatis.support.SqlMapClientDaoSupport;
import org.springframework.stereotype.Repository;
import com.sds.afi.cosmos.cmm.db.MainDao;
#Repository
//#SuppressWarnings("unchecked") // 부적절한 컴파일러의 경고를 제거
public class MainDaoImpl extends SqlMapClientDaoSupport implements MainDao {
#Autowired
private SqlMapClientTemplate sqlMapClientTemplate;
#SuppressWarnings("unchecked")
#Override
public List<HashMap> getUserInfo() throws DataAccessException {
List<HashMap> lists;
lists = sqlMapClientTemplate.queryForList("common.getList");
return lists;
}
}
This can happen if some class in the type-hierarchy of the exception is not on the class-path. In that case, its not possible to verify whether the exception really extends Throwable, whether it is a checked one or not, etc. Hence the errors. e.g superclass of Dataaccessexception : NestedRuntimeException may be missing from the class-path as it is in a differnt jar i.e. spring-core.
Your DataAccessException is not a subclass of Throwable class (extends Throwable). It should be, and without this inheritance, your code is not compilable with the current throws clause.
Here is an example: http://www.osix.net/modules/article/?id=754
I had this same issue when I upgraded to 5.X.X version. I have added Spring-core.jar file and it worked fine for me. Just adding this here because it may help some one. Spring txn jar , dao jar and spring core are must.
This means that in your getUserInfo() method there is no code that throws that exception. So just remove the throws clause from your method declaration.
I was facing same problem.
What I have done wrong was I have created Exception class(by mistake) of my own.
In other programs I was trying to extend Exception class(default) but complier(eclipse)was loading user defined Exception class giving me same error.
So please make sure you are not overriding any default class.

What is the "hasOwnProperty()" equivalent for interface?

What is the "hasOwnProperty()" equivalent for interface?
I have found this related bug at Adobe: https://bugs.adobe.com/jira/browse/FB-27683
Any workaround except try..catch statement?
Have you considered this?
if("foo" in bar){ ...
where "foo" is the name of a property and bar is the object reference as Interface?
Here it is in action in a real world scenario:
import flash.events.IEventDispatcher;
import flash.events.EventDispatcher;
var i:IEventDispatcher = new EventDispatcher();
if("dispatchEvent" in i){
trace(" I have dispatchEvent");
}
The other answer is better, but you can also use
i['hasOwnProperty']('dispatchEvent')

Serializing and unserializing case classes with lift-json

I'm attempting basic serialization/hydration with lift-json, but without success. As near as I can tell from the package readme, this should work. Help?
I'm using Scala 2.8.0 and Lift 2.2 cross-built for 2.8 with sbt ("net.liftweb" %% "lift-json" % "2.2").
import net.liftweb.json._
import net.liftweb.json.Serialization.{read, write}
implicit val formats = Serialization.formats(NoTypeHints)
case class Route(title: String)
val rt = new Route("x277a1")
val ser = write(rt)
// ser: String = {} ...
val deser = read[Route]("""{"title":"Some Title"}""")
// net.liftweb.json.MappingException: Parsed JSON values do not match with class constructor
Lift JSON's serialization does not work for case classes defined in REPL (paranamer can't find the bytecode to read the type metadata). Compile Route with scalac and then the above example works.
The same problem applies every time when the (de)serialuzed class is not on the classpath. In such case, paranamer can't read the parameter names. It is necessary to provide a custom ParameterNameReader.
Such problem applies for e.g.:
REPL (as mentioned) - unless you define the class outside the REPL and add via classpath.
Play Framework - unless you provide a simple custom ParameterNameReader (see below) or load the (de)serialized class as a Maven/Play/... dependency
Feel free to add another situation (you can edit this post).
The PlayParameterNameReader:
import net.liftweb.json.ParameterNameReader
import java.lang.reflect.Constructor
import play.classloading.enhancers.LocalvariablesNamesEnhancer
import scala.collection.JavaConversions._
object PlayParameterReader extends ParameterNameReader{
def lookupParameterNames(constructor: Constructor[_]) = LocalvariablesNamesEnhancer.lookupParameterNames(constructor)
}