BATCH-304: Modified the CommandLineJobRunner to accept a job name as an argument. Also modified the contract of JobParamterFactory to return an empty JobParameters or Properties if null is passed in, rather than throwing an IllegalArgumentException.

spring-batch-core/src/main/java/org/springframework/batch/core/domain/JobParameters.java

@@ -133,6 +133,13 @@ public class JobParameters {
 		return Collections.unmodifiableMap(dateMap);
 	}
 	
+	/**
+	 * @return true if the prameters is empty, false otherwise.
+	 */
+	public boolean isEmpty(){
+		return (dateMap.isEmpty() && longMap.isEmpty() && stringMap.isEmpty());
+	}
+	
 	/* 
 	 * Convenience method for validating that a the provided map only contains a particular
 	 * type as a value, with only a String as a key.

spring-batch-core/src/main/java/org/springframework/batch/core/runtime/JobParametersFactory.java

@@ -38,7 +38,8 @@ import org.springframework.batch.core.domain.JobParametersBuilder;
 public interface JobParametersFactory {
 
 	/**
-	 * Get a new {@link JobParameters} instance.
+	 * Get a new {@link JobParameters} instance.  If given null, or an empty
+	 * properties, an empty JobParameters will be returned.
 	 * 
 	 * @param properties
 	 *            the runtime parameters in the form of String literals.
@@ -47,7 +48,8 @@ public interface JobParametersFactory {
 	public JobParameters getJobParameters(Properties properties);
 
 	/**
-	 * The inverse operation: get a {@link Properties} instance.
+	 * The inverse operation: get a {@link Properties} instance.  If given
+	 * null or empty JobParameters, an empty Properties should be returned.
 	 * 
 	 * @param params
 	 * @return a representation of the parameters as properties