Test class should have exactly one public constructor

[Will Myers]

Hi,
I'm having a strange issue when running one of my tests, I get the exception:

java.lang.Exception: Test class should have exactly one public constructor

which is odd because my test has just one:

package com.db.ess.objectmodel.persistence.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import org.jmock.Expectations;
import org.jmock.Mockery;
import org.jmock.integration.junit4.JUnit4Mockery;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

public class TestAccrualCompounOnResetDAO {

    public TestAccrualCompounOnResetDAO() {
    }

	Mockery context = null;
	

	@Before
	public void setUp() throws Exception {

		context = new JUnit4Mockery();
	}

	@After
	public void tearDown() throws Exception {
	}

	@Test
	public void testFindByKey() {

	try {
			final Connection c = context.mock(Connection.class);
			final PreparedStatement stmt = context
					.mock(PreparedStatement.class);
			final ResultSet rs = context.mock(ResultSet.class);
			AccrualCompoundOnResetDAO dao = DAOFactory
					.getAccrualCompoundOnResetDAO(c);

			// Expectations
			context.checking(new Expectations() {
				{
					oneOf(c).prepareStatement(
							"exec OM_GetAccrualCompoudOnReset ?");
				}
			});
			context.checking(new Expectations() {
				{
					oneOf(stmt).setInt(1, 1);
				}
			});
			context.checking(new Expectations() {
				{
					oneOf(stmt).execute();
				}
			});
			context.checking(new Expectations() {
				{
					oneOf(rs).next();
				}
			});


		} catch (SQLException e) {
			// TODO Auto-generated catch block
			throw new RuntimeException("TODO: Handle this exception better", e);
	}

	}

}
    

so I can only assume that something else is either stripping out the constructor or adding another in at compile time, but what and why, and is there anything i can do about it?

Willy

[Ilja Preuss]

That is indeed strange. Can you show the stacktrace, please?

As an aside, your test method could simply throw the SqlException.

[Will Myers]

Here you go...

java.lang.Exception: Test class should have exactly one public constructor at org.junit.runners.BlockJUnit4ClassRunner.validateOnlyOneConstructor(BlockJUnit4ClassRunner.java:123) at org.junit.runners.BlockJUnit4ClassRunner.validateConstructor(BlockJUnit4ClassRunner.java:116) at org.junit.runners.BlockJUnit4ClassRunner.collectInitializationErrors(BlockJUnit4ClassRunner.java:111) at org.junit.runners.ParentRunner.validate(ParentRunner.java:253) at org.junit.runners.ParentRunner.<init>(ParentRunner.java:55) at org.junit.runners.BlockJUnit4ClassRunner.<init>(BlockJUnit4ClassRunner.java:56) at org.junit.internal.builders.JUnit4Builder.runnerForClass(JUnit4Builder.java:13) at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57) at org.junit.internal.builders.AllDefaultPossibilitiesBuilder.runnerForClass(AllDefaultPossibilitiesBuilder.java:29) at org.junit.runners.model.RunnerBuilder.safeRunnerForClass(RunnerBuilder.java:57) at org.junit.internal.requests.ClassRequest.getRunner(ClassRequest.java:24) at junit.framework.JUnit4TestAdapter.<init>(JUnit4TestAdapter.java:31) at junit.framework.JUnit4TestAdapter.<init>(JUnit4TestAdapter.java:24) at sun.reflect.GeneratedConstructorAccessor17.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.run(JUnitTestRunner.java:386) at org.apache.tools.ant.taskdefs.optional.junit.JUnitTask.executeInVM(JUnitTask.java:1339) at org.apache.tools.ant.taskdefs.optional.junit.JUnitTask.execute(JUnitTask.java:831) at org.apache.tools.ant.taskdefs.optional.junit.JUnitTask.executeOrQueue(JUnitTask.java:1785) at org.apache.tools.ant.taskdefs.optional.junit.JUnitTask.execute(JUnitTask.java:785) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288) at sun.reflect.GeneratedMethodAccessor6.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.Target.execute(Target.java:357) at org.apache.tools.ant.Target.performTasks(Target.java:385) at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1337) at org.apache.tools.ant.helper.SingleCheckExecutor.executeTargets(SingleCheckExecutor.java:38) at org.eclipse.ant.internal.ui.antsupport.EclipseSingleCheckExecutor.executeTargets(EclipseSingleCheckExecutor.java:30) at org.apache.tools.ant.Project.executeTargets(Project.java:1189) at org.apache.tools.ant.taskdefs.Ant.execute(Ant.java:416) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:288) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.Target.execute(Target.java:357) at org.apache.tools.ant.Target.performTasks(Target.java:385) at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1337) at org.apache.tools.ant.Project.executeTarget(Project.java:1306) at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41) at org.eclipse.ant.internal.ui.antsupport.EclipseDefaultExecutor.executeTargets(EclipseDefaultExecutor.java:32) at org.apache.tools.ant.Project.executeTargets(Project.java:1189) at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.run(InternalAntRunner.java:423) at org.eclipse.ant.internal.ui.antsupport.InternalAntRunner.main(InternalAntRunner.java:137)

[Ilja Preuss]

You seem to be using Ant? Can you show us the Ant task?

What happens if you run the test using the Eclipse test runner?

[Will Myers]

It runs fine through Eclipse which is strange..

here's the Ant target

 

	<path id="ess.commonlibs">
		<fileset dir="${lib.dir}">
			<include name="coherence-commandpattern-2.2.0.jar" />
			<include name="coherence-common-1.2.0.jar" />
			<include name="coherence.jar" />
			<include name="jconn3.jar" />
			<include name="tangosol.jar" />
			<include name="log4j-1.2.8.jar" />
			<include name="junit-4.5.jar" />
			<include name="GeneosJMX-0.2.2h.jar" />
			<include name="jaxen-1.1.1.jar"/>		
			<include name="asm-3.1.jar"/>	
			<include name="pmd-4.2.5.jar"/>
			<include name="api.jar"/>
			<include name="jmock-junit4-2.5.1.jar"/>
			<include name="jmock-2.5.1.jar"/>
			<include name="hamcrest-core-1.1.jar"/>
			<include name="hamcrest-library-1.1.jar"/>
		</fileset>	
	</path>
	<target name="testSuite" depends="testBanner, compile.test" description="Launch ObjectModel Junit Test Suite">
		<!-- Instrument the classes for EMMA -->
    	<emma enabled="${emma.enabled}">
    	    <instr instrpathref="component.emma.path" destdir="${out.instr.dir}" metadatafile="${reports.coverage}/metadataOM.emma" mode="copy">
    	    </instr>
    	</emma>	

		<junit failureproperty="junit.failure" errorproperty="junit.error" 
			showoutput="true" printsummary="withOutAndErr" haltonfailure="false" 
			fork="true">
			
			<jvmarg value="-Demma.coverage.out.file=${reports.coverage}/coverageOM.emma" />
			<jvmarg value="-Demma.coverage.out.merge=false" />
			<!--jvmarg value="-Dess_config.properties=C:\workspace3.5\ess7-client_interest_v1\ess\config\ess_config.properties-local" /-->
			
			<classpath>
				<!--pathelement location="C:\workspace3.5\jython-config\db-ess\config\coherence" /-->
				<pathelement location="${coherence.config.dir}" />
				<pathelement location="${out.instr.dir}" />
				<pathelement location="${test.dest.dir}" />
				<pathelement location="${jar.build.dir}" />
				<path        refid="emma.lib"/>
			</classpath>			
			<classpath refid="ess.commonlibs" />
			
			<batchtest filtertrace="false" fork="false" todir="${reports.tests}">
	            <formatter type="xml"/>
	            <fileset dir="${test.dest.dir}"> 
	            	<exclude name="**/TestBase*.class" />
	            	<include name="**/Test*.class" />
	            </fileset>
	        </batchtest>        				        
	  	</junit>
		
		<antcall target="gen_coverage"></antcall>		
		<antcall target="junitReports"></antcall>				
        
		<fail message="Failed Junit test cases." if="junit.failure" />
        <fail message="Erroneous Junit test cases." if="junit.error" />        
	</target>   

[Ilja Preuss]

How do you know that it's that class that's causing the problem?

[Will Myers]

the tests print out a report of all the failures

[Will Myers]

Actually something very odd is happening, it looks like it is interpretting the Expectations as seperate tests and failing them because they don't have a constructor, is this normal??

[Ilja Preuss]

Oh right - look at your include:

include name="**/Test*.class"

That includes the anonymous inner classes.

I've never seen that happening before, because our coding convention is to have test classes *end* with "Test" - which elegantly circumvents this problem

You should probably add an

exclude name="**/*$*.class"

to your fileset.

[Will Myers]

Doh!

Thanks for your help, this has been driving me mad all day!

[Ilja Preuss]

You're welcome! I know how these things can drive you insane...