Add getJobInstance method in JobExplorer/JobRepository

Resolves #3930

spring-batch-core/src/main/java/org/springframework/batch/core/explore/JobExplorer.java

@@ -20,6 +20,7 @@ import java.util.Set;
 
 import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobInstance;
+import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.launch.NoSuchJobException;
 import org.springframework.batch.item.ExecutionContext;
@@ -34,6 +35,7 @@ import org.springframework.lang.Nullable;
  * @author Michael Minella
  * @author Will Schipp
  * @author Mahmoud Ben Hassine
+ * @author Parikshit Dutta
  * @since 2.0
  */
 public interface JobExplorer {
@@ -92,6 +94,16 @@ public interface JobExplorer {
 	@Nullable
 	JobInstance getJobInstance(@Nullable Long instanceId);
 
+	/**
+	 * @param jobName {@link String} name for the jobInstance.
+	 * @param jobParameters {@link JobParameters} parameters for the jobInstance.
+	 * @return the {@link JobInstance} with this name and parameters, or null
+	 *
+	 * @since 5.0
+	 */
+	@Nullable
+	JobInstance getJobInstance(String jobName, JobParameters jobParameters);
+
 	/**
 	 * Retrieve job executions by their job instance. The corresponding step executions
 	 * may not be fully hydrated (for example, their execution context may be missing),

spring-batch-core/src/main/java/org/springframework/batch/core/explore/support/SimpleJobExplorer.java

@@ -18,6 +18,7 @@ package org.springframework.batch.core.explore.support;
 
 import org.springframework.batch.core.JobExecution;
 import org.springframework.batch.core.JobInstance;
+import org.springframework.batch.core.JobParameters;
 import org.springframework.batch.core.StepExecution;
 import org.springframework.batch.core.explore.JobExplorer;
 import org.springframework.batch.core.launch.NoSuchJobException;
@@ -38,6 +39,8 @@ import java.util.Set;
  * @author Michael Minella
  * @author Will Schipp
  * @author Mahmoud Ben Hassine
+ * @author Parikshit Dutta
+ *
  * @see JobExplorer
  * @see JobInstanceDao
  * @see JobExecutionDao
@@ -185,6 +188,19 @@ public class SimpleJobExplorer implements JobExplorer {
 		return jobInstanceDao.getJobInstance(instanceId);
 	}
 
+	/*
+	 * (non-Javadoc)
+	 *
+	 * @see
+	 * org.springframework.batch.core.explore.JobExplorer#getJobInstance(java
+	 * .lang.String, org.springframework.batch.core.JobParameters)
+	 */
+	@Nullable
+	@Override
+	public JobInstance getJobInstance(String jobName, JobParameters jobParameters) {
+		return jobInstanceDao.getJobInstance(jobName, jobParameters);
+	}
+
 	/*
 	 * (non-Javadoc)
 	 *

spring-batch-core/src/main/java/org/springframework/batch/core/repository/JobRepository.java

@@ -46,6 +46,7 @@ import java.util.List;
  * @author David Turanski
  * @author Michael Minella
  * @author Mahmoud Ben Hassine
+ * @author Parikshit Dutta
  */
 public interface JobRepository {
 
@@ -186,6 +187,16 @@ public interface JobRepository {
 	 */
 	void updateExecutionContext(JobExecution jobExecution);
 
+	/**
+	 * @param jobName {@link String} the name of the jobInstance
+	 * @param jobParameters {@link JobParameters} parameters identifying the {@link JobInstance}
+	 * @return the {@link JobInstance} with name and parameters, or null
+	 *
+	 * @since 5.0
+	 */
+	@Nullable
+	JobInstance getJobInstance(String jobName, JobParameters jobParameters);
+
 	/**
 	 * @param jobInstance {@link JobInstance} instance containing the step executions.
 	 * @param stepName the name of the step execution that might have run.

spring-batch-core/src/main/java/org/springframework/batch/core/repository/support/SimpleJobRepository.java

@@ -53,6 +53,8 @@ import java.util.List;
  * @author David Turanski
  * @author Mahmoud Ben Hassine
  * @author Baris Cubukcuoglu
+ * @author Parikshit Dutta
+ *
  * @see JobRepository
  * @see JobInstanceDao
  * @see JobExecutionDao
@@ -244,6 +246,11 @@ public class SimpleJobRepository implements JobRepository {
 		ecDao.updateExecutionContext(jobExecution);
 	}
 
+	@Override
+	public JobInstance getJobInstance(String jobName, JobParameters jobParameters) {
+		return jobInstanceDao.getJobInstance(jobName, jobParameters);
+	}
+
 	@Override
 	@Nullable
 	public StepExecution getLastStepExecution(JobInstance jobInstance, String stepName) {