BATCH-1053: Updated javadocs to explain the behavior of getStep and getState if the step/state is not found.

spring-batch-core/src/main/java/org/springframework/batch/core/job/AbstractJob.java

@@ -126,7 +126,8 @@ public abstract class AbstractJob implements Job, BeanNameAware, InitializingBea
 	}
 
 	/**
-	 * Retrieve the step with the given name
+	 * Retrieve the step with the given name. An IllegalStateException is thrown
+	 * if there is no Step with the given name.
 	 * 
 	 * @param stepName
 	 * @return the step

spring-batch-core/src/main/java/org/springframework/batch/core/job/flow/Flow.java

@@ -29,8 +29,11 @@ public interface Flow {
 	String getName();
 
 	/**
+	 * Retrieve the State with the given name. An IllegalStateException is
+	 * thrown if there is no State with the given name.
+	 * 
 	 * @param stateName
-	 * @return the State in the flow with given name 
+	 * @return the State
 	 */
 	public State getState(String stateName);
 	

spring-batch-core/src/main/java/org/springframework/batch/core/job/flow/FlowJob.java

@@ -65,8 +65,10 @@ public class FlowJob extends AbstractJob {
 	 */
 	public Step getStep(String stepName){
 		State state = this.flow.getState(stepName);
-		Assert.isInstanceOf(StepState.class, state, "State is not a StepState: [" + stepName + "]");
-		return ((StepState) state).getStep();
+		if(state instanceof StepState){
+			return ((StepState) state).getStep();
+		}
+		throw new IllegalStateException("State is not a StepState: [" + stepName + "]");		
 	}
 	
 	/**

spring-batch-core/src/main/java/org/springframework/batch/core/job/flow/support/SimpleFlow.java

@@ -30,7 +30,6 @@ import org.springframework.batch.core.job.flow.FlowExecution;
 import org.springframework.batch.core.job.flow.FlowExecutionException;
 import org.springframework.batch.core.job.flow.FlowExecutor;
 import org.springframework.beans.factory.InitializingBean;
-import org.springframework.util.Assert;
 
 /**
  * A {@link Flow} that branches conditionally depending on the exit status of
@@ -88,7 +87,9 @@ public class SimpleFlow implements Flow, InitializingBean {
 	 */
 	public State getState(String stateName) {
 		State state = stateMap.get(stateName);
-		Assert.notNull(state, "No State found with name: [" + stateName + "]");
+		if(state == null){
+			throw new IllegalStateException("No State found with name: [" + stateName + "]");
+		}
 		return state;
 	}
 

spring-batch-core/src/test/java/org/springframework/batch/core/job/flow/support/SimpleFlowTests.java

@@ -215,7 +215,7 @@ public class SimpleFlowTests {
 		assertEquals("step1", state.getName());
 	}
 
-	@Test(expected = IllegalArgumentException.class)
+	@Test(expected = IllegalStateException.class)
 	public void testGetStateDoesNotExist() throws Exception {
 		flow.setStateTransitions(Collections.singletonList(StateTransition.createEndStateTransition(new StubState(
 				"step1"))));

spring-batch-test/src/main/java/org/springframework/batch/test/AbstractJobTests.java

@@ -138,19 +138,13 @@ public abstract class AbstractJobTests {
 	}
 
 	/**
-	 * Launch just the specified step in the job.
+	 * Launch just the specified step in the job. An IllegalStateException is thrown
+	 * if there is no Step with the given name.
 	 * 
 	 * @param stepName
 	 */
 	public JobExecution launchStep(String stepName) {
-		Step step;
-		try {
-			step = this.job.getStep(stepName);
-		}
-		catch (IllegalArgumentException e) {
-			throw new IllegalStateException("No Step found with name: [" + stepName + "]", e);
-		}
-		return getStepRunner().launchStep(step);
+		return getStepRunner().launchStep(this.job.getStep(stepName));
 	}
 
 	/**