BAEL-3298 Spring batch retry job (#8690)

* BAEL-3298 Spring batch retry job

* BAEL-3298 Adding tests and refactoring

* BAEL-3298 Some more refactoring

* Review comments

* Some refactoring

* Refactoring RetryItemProcessor

* Minor refactoring in test class

* BAEL-3298 Some more refactoring

* BAEL-3298 Using @MockBean

* BAEL-3298 minor update

* BAEL-3298 Updating names of testcases

* updating id to 9999

* Updating id to 9999

* Updating id to 9999

spring-batch/src/test/java/org/baeldung/batch/SpringBatchRetryIntegrationTest.java

@@ -0,0 +1,90 @@
+package org.baeldung.batch;
+
+import org.apache.http.client.methods.CloseableHttpResponse;
+import org.apache.http.conn.ConnectTimeoutException;
+import org.apache.http.entity.StringEntity;
+import org.apache.http.impl.client.CloseableHttpClient;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.springframework.batch.core.ExitStatus;
+import org.springframework.batch.core.JobExecution;
+import org.springframework.batch.core.JobInstance;
+import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.JobParametersBuilder;
+import org.springframework.batch.test.AssertFile;
+import org.springframework.batch.test.JobLauncherTestUtils;
+import org.springframework.batch.test.context.SpringBatchTest;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.core.io.FileSystemResource;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import static org.hamcrest.CoreMatchers.containsString;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.when;
+
+@RunWith(SpringRunner.class)
+@SpringBatchTest
+@EnableAutoConfiguration
+@ContextConfiguration(classes = { SpringBatchRetryConfig.class })
+public class SpringBatchRetryIntegrationTest {
+
+    private static final String TEST_OUTPUT = "xml/retryOutput.xml";
+    private static final String EXPECTED_OUTPUT = "src/test/resources/output/batchRetry/retryOutput.xml";
+
+    @Autowired
+    private JobLauncherTestUtils jobLauncherTestUtils;
+
+    @MockBean
+    private CloseableHttpClient closeableHttpClient;
+
+    @Mock
+    private CloseableHttpResponse httpResponse;
+
+    @Test
+    public void whenEndpointAlwaysFail_thenJobFails() throws Exception {
+        when(closeableHttpClient.execute(any()))
+          .thenThrow(new ConnectTimeoutException("Endpoint is down"));
+
+        JobExecution jobExecution = jobLauncherTestUtils.launchJob(defaultJobParameters());
+        JobInstance actualJobInstance = jobExecution.getJobInstance();
+        ExitStatus actualJobExitStatus = jobExecution.getExitStatus();
+
+        assertThat(actualJobInstance.getJobName(), is("retryBatchJob"));
+        assertThat(actualJobExitStatus.getExitCode(), is("FAILED"));
+        assertThat(actualJobExitStatus.getExitDescription(), containsString("org.apache.http.conn.ConnectTimeoutException"));
+    }
+
+    @Test
+    public void whenEndpointFailsTwicePasses3rdTime_thenSuccess() throws Exception {
+        FileSystemResource expectedResult = new FileSystemResource(EXPECTED_OUTPUT);
+        FileSystemResource actualResult = new FileSystemResource(TEST_OUTPUT);
+
+        //fails for first two calls and passes third time onwards
+        when(httpResponse.getEntity())
+          .thenReturn(new StringEntity("{ \"age\":10, \"postCode\":\"430222\" }"));
+        when(closeableHttpClient.execute(any()))
+          .thenThrow(new ConnectTimeoutException("Timeout count 1"))
+          .thenThrow(new ConnectTimeoutException("Timeout count 2"))
+          .thenReturn(httpResponse);
+
+        JobExecution jobExecution = jobLauncherTestUtils.launchJob(defaultJobParameters());
+        JobInstance actualJobInstance = jobExecution.getJobInstance();
+        ExitStatus actualJobExitStatus = jobExecution.getExitStatus();
+
+        assertThat(actualJobInstance.getJobName(), is("retryBatchJob"));
+        assertThat(actualJobExitStatus.getExitCode(), is("COMPLETED"));
+        AssertFile.assertFileEquals(expectedResult, actualResult);
+    }
+    
+    private JobParameters defaultJobParameters() {
+        JobParametersBuilder paramsBuilder = new JobParametersBuilder();
+        paramsBuilder.addString("jobID", String.valueOf(System.currentTimeMillis()));
+        return paramsBuilder.toJobParameters();
+    }
+}

spring-batch/src/test/resources/output/batchRetry/retryOutput.xml

@@ -0,0 +1 @@
+<?xml version="1.0" encoding="UTF-8"?><transactionRecord><transactionRecord><age>10</age><amount>10000.0</amount><postCode>430222</postCode><transactionDate>2015-10-31T00:00:00+05:30</transactionDate><userId>1234</userId><username>sammy</username></transactionRecord><transactionRecord><age>10</age><amount>12321.0</amount><postCode>430222</postCode><transactionDate>2015-12-03T00:00:00+05:30</transactionDate><userId>9999</userId><username>john</username></transactionRecord></transactionRecord>