Add JobParametersIncrementer implementation based on a DataFieldMaxValueIncrementer

Issue #1521

Author: fmbenhassine

spring-batch-core/src/main/java/org/springframework/batch/core/launch/support/DataFieldMaxValueJobParametersIncrementer.java

@@ -0,0 +1,98 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.core.launch.support;
+
+import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.JobParametersBuilder;
+import org.springframework.batch.core.JobParametersIncrementer;
+import org.springframework.jdbc.support.incrementer.DataFieldMaxValueIncrementer;
+import org.springframework.util.Assert;
+
+/**
+ * This incrementer uses a {@link DataFieldMaxValueIncrementer} to generate
+ * the sequence of values to use as job instance discriminator.
+ * 
+ * @author Gregory D. Hopkins
+ * @author Mahmoud Ben Hassine
+ */
+public class DataFieldMaxValueJobParametersIncrementer implements JobParametersIncrementer {
+
+	/**
+	 * Default key used as a job parameter.
+	 */
+	public static final String DEFAULT_KEY = "run.id";
+
+	private String key = DEFAULT_KEY;
+	private DataFieldMaxValueIncrementer dataFieldMaxValueIncrementer;
+
+	/**
+	 * Create a new {@link DataFieldMaxValueJobParametersIncrementer}.
+	 * 
+	 * @param dataFieldMaxValueIncrementer the incrementer to use to generate
+	 * the sequence of values. Must not be {@code null}.
+	 */
+	public DataFieldMaxValueJobParametersIncrementer(DataFieldMaxValueIncrementer dataFieldMaxValueIncrementer) {
+		Assert.notNull(dataFieldMaxValueIncrementer, "dataFieldMaxValueIncrementer must not be null");
+		this.dataFieldMaxValueIncrementer = dataFieldMaxValueIncrementer;
+	}
+
+	@Override
+	public JobParameters getNext(JobParameters jobParameters) {
+		return new JobParametersBuilder(jobParameters == null ? new JobParameters() : jobParameters)
+				.addLong(this.key, this.dataFieldMaxValueIncrementer.nextLongValue())
+				.toJobParameters();
+	}
+
+	/**
+	 * Get the key. Defaults to {@link #DEFAULT_KEY}.
+	 * 
+	 * @return the key
+	 */
+	public String getKey() {
+		return this.key;
+	}
+
+	/**
+	 * The name of the key to use as a job parameter. Defaults to {@link #DEFAULT_KEY}.
+	 * Must not be {@code null} or empty.
+	 *
+	 * @param key the key to set
+	 */
+	public void setKey(String key) {
+		Assert.hasText(key, "key must not be null or empty");
+		this.key = key;
+	}
+
+	/**
+	 * Get the incrementer.
+	 * 
+	 * @return the incrementer
+	 */
+	public DataFieldMaxValueIncrementer getDataFieldMaxValueIncrementer() {
+		return this.dataFieldMaxValueIncrementer;
+	}
+
+	/**
+	 * The incrementer to generate the sequence of values. Must not be {@code null}.
+	 *
+	 * @param dataFieldMaxValueIncrementer the incrementer to generate the sequence of values
+	 */
+	public void setDataFieldMaxValueIncrementer(DataFieldMaxValueIncrementer dataFieldMaxValueIncrementer) {
+		Assert.notNull(dataFieldMaxValueIncrementer, "dataFieldMaxValueIncrementer must not be null");
+		this.dataFieldMaxValueIncrementer = dataFieldMaxValueIncrementer;
+	}
+
+}

spring-batch-core/src/test/java/org/springframework/batch/core/launch/support/DataFieldMaxValueJobParametersIncrementerTests.java

@@ -0,0 +1,113 @@
+/*
+ * Copyright 2020 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.batch.core.launch.support;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+import org.springframework.batch.core.JobParameters;
+import org.springframework.batch.core.JobParametersBuilder;
+import org.springframework.jdbc.support.incrementer.DataFieldMaxValueIncrementer;
+
+import static org.junit.Assert.fail;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+/**
+ * @author Mahmoud Ben Hassine
+ */
+public class DataFieldMaxValueJobParametersIncrementerTests {
+
+	private final DataFieldMaxValueIncrementer incrementer = mock(DataFieldMaxValueIncrementer.class);
+
+	@Test
+	public void testInvalidKey() {
+		DataFieldMaxValueJobParametersIncrementer jobParametersIncrementer
+				= new DataFieldMaxValueJobParametersIncrementer(this.incrementer);
+		try {
+			jobParametersIncrementer.setKey("");
+			fail("Must fail if the key is empty");
+		}
+		catch (IllegalArgumentException exception) {
+			Assert.assertEquals("key must not be null or empty", exception.getMessage());
+		}
+	}
+
+	@Test
+	public void testInvalidDataFieldMaxValueIncrementer() {
+		try {
+			new DataFieldMaxValueJobParametersIncrementer(null);
+			fail("Must fail if the incrementer is null");
+		}
+		catch (IllegalArgumentException exception) {
+			Assert.assertEquals("dataFieldMaxValueIncrementer must not be null", exception.getMessage());
+		}
+	}
+
+	@Test
+	public void testGetNext() {
+		// given
+		JobParameters jobParameters = new JobParameters();
+		when(this.incrementer.nextLongValue()).thenReturn(10L);
+		DataFieldMaxValueJobParametersIncrementer jobParametersIncrementer
+				= new DataFieldMaxValueJobParametersIncrementer(this.incrementer);
+
+		// when
+		JobParameters nextParameters = jobParametersIncrementer.getNext(jobParameters);
+
+		// then
+		Long runId = nextParameters.getLong("run.id");
+		Assert.assertEquals(new Long(10) ,runId);
+	}
+
+	@Test
+	public void testGetNextAppend() {
+		// given
+		JobParameters jobParameters = new JobParametersBuilder()
+				.addString("foo", "bar")
+				.toJobParameters();
+		when(this.incrementer.nextLongValue()).thenReturn(10L);
+		DataFieldMaxValueJobParametersIncrementer jobParametersIncrementer
+				= new DataFieldMaxValueJobParametersIncrementer(this.incrementer);
+
+		// when
+		JobParameters nextParameters = jobParametersIncrementer.getNext(jobParameters);
+
+		// then
+		Long runId = nextParameters.getLong("run.id");
+		String foo = nextParameters.getString("foo");
+		Assert.assertEquals(new Long(10) ,runId);
+		Assert.assertEquals("bar" ,foo);
+	}
+
+	@Test
+	public void testGetNextOverride() {
+		// given
+		JobParameters jobParameters = new JobParametersBuilder()
+				.addLong("run.id", 1L)
+				.toJobParameters();
+		when(this.incrementer.nextLongValue()).thenReturn(10L);
+		DataFieldMaxValueJobParametersIncrementer jobParametersIncrementer
+				= new DataFieldMaxValueJobParametersIncrementer(this.incrementer);
+
+		// when
+		JobParameters nextParameters = jobParametersIncrementer.getNext(jobParameters);
+
+		// then
+		Long runId = nextParameters.getLong("run.id");
+		Assert.assertEquals(new Long(10) ,runId);
+	}
+}