Facing issue in mule testing - mule

Question

I am facing problem with mule testing. I just tries out simple functional testing example.
following is my flow
<flow name="muletestFlow1" doc:name="muletestFlow1">
<http:inbound-endpoint exchange-pattern="request-response" host="localhost" port="8081" path="test" doc:name="HTTP"/>
<response>
<object-to-string-transformer />
</response>
<component class="com.org.Square" doc:name="Square"/>
<component class="com.org.Neg doc:name="Neg"/>
</flow>
and following is my testing class
#Test
public void testSquareAddInverse() throws Exception {
MuleClient client = muleContext.getClient();
MuleMessage reply = client.send ("http://localhost:8081/test", "3", null, 5000);
assertNotNull(reply);
assertNotNull(reply.getPayload());
assertTrue(reply.getPayload() instanceof String);
String result = (String)reply.getPayload();
assertEquals("-9", result);
If i run above class as junit test then got following error.
java.lang.AssertionError
at org.junit.Assert.fail(Assert.java:92)
at org.junit.Assert.assertTrue(Assert.java:43)
at org.junit.Assert.assertTrue(Assert.java:54)
at com.test.TestEx.testSquareAddInverse(TestEx.java:25)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:622)
at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:44)
at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:15)
at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:41)
at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:20)
at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
at org.junit.internal.runners.statements.RunAfters.evaluate(RunAfters.java:31)
at org.junit.rules.TestWatcher$1.evaluate(TestWatcher.java:46)
at org.junit.internal.runners.statements.FailOnTimeout$1.run(FailOnTimeout.java:28)
What is the solution please help me.
If i comment this line
assertTrue(reply.getPayload() instanceof String);
then got following error.
java.lang.ClassCastException: org.mule.transport.http.ReleasingInputStream cannot be cast to java.lang.String
What is the wrong in this code? How can i solve this problem. please help me
Thanks in advance

Answer 1

Since you call the flow through http protocol, which implicitly transforms the payload type. So the reply in the unit test will not contain a String but a InputStream. This is expected so you should test for a InputStream instead of a String. To get the value as a String you can use the method MuleMessage#getPayload(java.lang.Class) that will transform the payload to a String using the registered transformers.
#Test
public void testGetNegaiveNine() throws Exception {
MuleClient client = muleContext.getClient();
MuleMessage reply = client.send ("http://localhost:8081/test", "3", null, 5000);
assertNotNull(reply);
assertNotNull(reply.getPayload());
assertTrue(reply.getPayload() instanceof InputStream);
String result = reply.getPayload(String.class);
assertEquals("-9", result);
}
The exception you get in the flow
after that.
"DefaultJavaComponent{muletestFlow1.component.3418143}. Message payload is of type: ContentLengthInputStream"
is because the components can not handle the payload that the message inside your flow has. Since you are sending a HTTP POST into the flow the payload of the incoming message is a ContenLengthInputStream and you components expects a String.
So you will have to transform the payload into a String by adding a object-to-string transformer before the components. The complete flow would then be something like this.
<flow name="muletestFlow1" doc:name="muletestFlow1">
<http:inbound-endpoint exchange-pattern="request-response" host="localhost" port="8081" path="test" doc:name="HTTP"/>
<response>
<!-- Ensure that the response is a String -->
<object-to-string-transformer />
</response>
<!-- Ensure that the incoming request is a String -->
<object-to-string-transformer />
<component class="com.org.Square" doc:name="Square"/>
<component class="com.org.Neg doc:name="Neg"/>
</flow>