Thread-safe property resolution for concurrent execution of the same job: Added JobBuilder.createJob(String, Consumer<PropertyResolver>>) and deprecated JobProperties

Author: chrisgleissner

README.md

@@ -8,7 +8,7 @@
 
 REST API for <a href="https://spring.io/projects/spring-batch">Spring Batch</a> based on <a href="https://github.com/spring-projects/spring-boot">Spring Boot 2.2</a> and <a href="https://github.com/spring-projects/spring-hateoas">Spring HATOEAS</a>. It comes with an OpenAPI 3 documentation provided by <a href="https://github.com/springdoc/springdoc-openapi">Springdoc</a>.
 
-Supports Java 8 and above. Tested using OpenJDK 8, 11, and 14.
+Supports Java 8 and above. Tested on OpenJDK 8, 11, and 14.
 
 ## Features
 - Get information on jobs, job executions, and Quartz schedules
@@ -227,29 +227,60 @@ This disables the global exception handling via `com.github.chrisgleissner.sprin
 
 ## Job Property Overrides
 
-Properties can be overridden when starting a job via REST. These overrides can then be accessed from a job either via:
+Properties can be overridden when starting a job via REST. You can then access these overrides in one of the following ways.
+
+### @Value
+
+Annotate your Spring bean method with `@StepScope` and use the `@Value("#{jobParameters['name']}")` annotation on a method parameter 
+to specify the desired job parameter name. 
+
+Please note that this approach won't transparently fall back to Spring environment properties. Thus,
+if this is desired, you should manually check if a job parameter is `null` and in this case return it from the Spring `Environment` instance. 
+
+Example:
+```java
+@Bean @StepScope  
+ItemWriter<Object> writer(@Value("#{jobParameters['propName']}") String prop) {
+    // ... 
+}
+```
+
+### PropertyResolver
+
+When using `AdhocStarter`, you can create a `Job` using a `JobBuilder` and pass in a `Consumer<PropertyResolver>`. 
+
+Properties looked up from this `PropertyResolver` transparently fall back to the Spring environment if properties can't be found in the job parameters.
+
+Example:
+```java
+Job job = jobBuilder.createJob("sampleJob", propertyResolver -> {
+    String propertyValue = propertyResolver.getProperty("sampleProperty");
+    ...
+});
+```
+### JobProperties
+
+In case you don't execute the same job concurrently, you may also look up properties from the `JobProperties` singleton. 
+
+Properties looked up from this singleton transparently fall back to the Spring environment if properties can't be found in the 
+job parameters. 
+
+This approach is *deprecated* as it doesn't work with concurrent execution of the same job. Therefore, it is recommended to use one
+of the other approaches.
+
+Example:
 ```java
 @Bean
 ItemWriter<Object> writer() {
     return new ItemWriter<Object>() {
         @Override
         public void write(List<?> items) throws Exception {
-           String prop = JobPropertyResolvers.JobProperties.of("jobName").getProperty("propName");
+           String prop = JobPropertyResolvers.JobProperties.of("sampleJob").getProperty("sampleProperty");
            // ...
         }
     }
 }
 ```
-or alternatively by using `@StepScope`-annotated beans:
-```java
-@StepScope
-@Bean 
-ItemWriter<Object> writer(@Value("#{jobParameters['propName']}") String prop) {
-    // ... 
-}
-```
-
-If a property is not overridden, it is resolved against the Spring environment. All overrides are reverted on job completion.
 
 ## Utilities
 

api/src/test/java/com/github/chrisgleissner/springbatchrest/api/core/RestTest.java

@@ -5,7 +5,6 @@
 import com.github.chrisgleissner.springbatchrest.util.core.JobBuilder;
 import com.github.chrisgleissner.springbatchrest.util.core.JobConfig;
 import com.github.chrisgleissner.springbatchrest.util.core.config.AdHocBatchConfig;
-
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -26,7 +25,6 @@
 import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.atomic.AtomicBoolean;
 
-import static com.github.chrisgleissner.springbatchrest.util.core.property.JobPropertyResolvers.JobProperties;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.springframework.batch.core.ExitStatus.COMPLETED;
 import static org.springframework.boot.test.context.SpringBootTest.WebEnvironment.RANDOM_PORT;
@@ -56,11 +54,11 @@ public class RestTest {
     @Before
     public void setUp() {
         if (firstExecution.compareAndSet(true, false)) {
-            Job job = jobBuilder.createJob(JOB_NAME, () -> {
-                String propertyValue = JobProperties.of(JOB_NAME).getProperty(PROPERTY_NAME);
+            Job job = jobBuilder.createJob(JOB_NAME, propertyResolver -> {
+                String propertyValue = propertyResolver.getProperty(PROPERTY_NAME);
                 propertyValues.add(propertyValue);
 
-                String exceptionMessage = JobProperties.of(JOB_NAME).getProperty(EXCEPTION_MESSAGE_PROPERTY_NAME);
+                String exceptionMessage = propertyResolver.getProperty(EXCEPTION_MESSAGE_PROPERTY_NAME);
                 if (exceptionMessage != null)
                     throw new RuntimeException(exceptionMessage);
 

example/api/src/main/java/com/github/chrisgleissner/springbatchrest/example/core/PersonJobConfig.java

@@ -4,11 +4,10 @@
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.batch.core.Job;
 import org.springframework.batch.core.Step;
-import org.springframework.batch.core.configuration.DuplicateJobException;
-import org.springframework.batch.core.configuration.JobFactory;
 import org.springframework.batch.core.configuration.JobRegistry;
 import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
 import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
@@ -22,39 +21,32 @@
 import org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper;
 import org.springframework.batch.item.function.FunctionItemProcessor;
 import org.springframework.batch.item.support.CompositeItemProcessor;
-import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Qualifier;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
 import org.springframework.core.io.ClassPathResource;
 
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Optional;
 
-import static com.github.chrisgleissner.springbatchrest.util.core.property.JobPropertyResolvers.JobProperties;
 import static com.google.common.collect.Lists.newArrayList;
 import static java.util.Collections.synchronizedList;
 
-@Slf4j
-@Configuration
-@EnableBatchProcessing
+@Configuration @EnableBatchProcessing @RequiredArgsConstructor @Slf4j
 public class PersonJobConfig {
-
     static final String JOB_NAME = "personJob";
     static final String LAST_NAME_PREFIX = "lastNamePrefix";
 
-    @Autowired
-    JobBuilderFactory jobs;
-
-    @Autowired
-    StepBuilderFactory steps;
-
-    @Autowired
-    JobRegistry jobRegistry;
+    private final JobBuilderFactory jobs;
+    private final StepBuilderFactory steps;
+    private final JobRegistry jobRegistry;
+    private final Environment environment;
 
     @Bean
-    Job personJob(@Qualifier("personStep") Step personStep) throws DuplicateJobException {
+    Job personJob(@Qualifier("personStep") Step personStep) {
         return JobBuilder.registerJob(jobRegistry, jobs.get(JOB_NAME)
                 .incrementer(new RunIdIncrementer())
                 .start(personStep)
@@ -78,31 +70,32 @@ FlatFileItemReader<Person> personReader() {
                 .name("personItemReader")
                 .resource(new ClassPathResource("person.csv"))
                 .delimited()
-                .names(new String[]{"firstName", "lastName"})
+                .names("firstName", "lastName")
                 .fieldSetMapper(new BeanWrapperFieldSetMapper<Person>() {{
                     setTargetType(Person.class);
                 }})
                 .build();
     }
 
-    @Bean
-    ItemProcessor personProcessor(@Qualifier("personNameCaseChange") ItemProcessor personNameCaseChange) {
+    @Bean @StepScope
+    ItemProcessor personProcessor(
+            @Qualifier("personNameCaseChange") ItemProcessor personNameCaseChange,
+            @Value("#{jobParameters['" + LAST_NAME_PREFIX + "']}") String lastNamePrefix) {
         CompositeItemProcessor p = new CompositeItemProcessor();
-        p.setDelegates(newArrayList(personNameFilter(), personNameCaseChange));
+        p.setDelegates(newArrayList(
+                personNameFilter(Optional.ofNullable(lastNamePrefix).orElseGet(() -> environment.getProperty(LAST_NAME_PREFIX))),
+                personNameCaseChange));
         return p;
     }
 
-    @Bean
-    ItemProcessor personNameFilter() {
+    private ItemProcessor personNameFilter(String lastNamePrefix) {
         return new FunctionItemProcessor<Person, Person>(p -> {
-            String lastNamePrefix = JobProperties.of(PersonJobConfig.JOB_NAME).getProperty(LAST_NAME_PREFIX);
             log.info("Last name prefix: {}", lastNamePrefix);
             return p.lastName != null && p.lastName.startsWith(lastNamePrefix) ? p : null;
         });
     }
 
-    @StepScope
-    @Bean
+    @Bean @StepScope
     ItemProcessor personNameCaseChange(@Value("#{jobParameters['upperCase']}") Boolean upperCaseParam) {
         boolean upperCase = upperCaseParam == null ? false : upperCaseParam;
         log.info("personNameCaseChange(upperCase={})", upperCase);
@@ -116,8 +109,14 @@ CacheItemWriter<Person> personWriter() {
         return new CacheItemWriter<>();
     }
 
-    public class CacheItemWriter<T> implements ItemWriter<T> {
-        private List<T> items = synchronizedList(new LinkedList<>());
+    @Data @NoArgsConstructor @AllArgsConstructor
+    public static class Person {
+        private String firstName;
+        private String lastName;
+    }
+
+    public static class CacheItemWriter<T> implements ItemWriter<T> {
+        private final List<T> items = synchronizedList(new LinkedList<>());
 
         @Override
         public void write(List<? extends T> items) {
@@ -132,12 +131,4 @@ public void clear() {
             items.clear();
         }
     }
-
-    @Data
-    @NoArgsConstructor
-    @AllArgsConstructor
-    public static class Person {
-        private String firstName;
-        private String lastName;
-    }
 }

example/api/src/test/java/com/github/chrisgleissner/springbatchrest/example/core/PersonJobTest.java

@@ -31,18 +31,12 @@
 @SpringBootTest(webEnvironment = DEFINED_PORT)
 @EnableAutoConfiguration
 public class PersonJobTest {
-
-    @LocalServerPort
-    private int port;
-
-    @Autowired
-    private TestRestTemplate restTemplate;
-
-    @Autowired
-    private PersonJobConfig.CacheItemWriter<PersonJobConfig.Person> cacheItemWriter;
+    @LocalServerPort private int port;
+    @Autowired private TestRestTemplate restTemplate;
+    @Autowired private PersonJobConfig.CacheItemWriter<PersonJobConfig.Person> cacheItemWriter;
 
     @Test
-    public void canStartJob() throws NoSuchJobException {
+    public void canStartJob() {
         cacheItemWriter.clear();
         startJob(Optional.empty(), Optional.empty());
         assertThat(cacheItemWriter.getItems()).hasSize(5);

example/quartz-api/src/main/java/com/github/chrisgleissner/springbatchrest/example/quartz/PersonJobConfig.java

@@ -4,6 +4,7 @@
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
+import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import org.springframework.batch.core.Job;
 import org.springframework.batch.core.Step;
@@ -23,30 +24,25 @@
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.env.Environment;
 import org.springframework.core.io.ClassPathResource;
 
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Optional;
 
-import static com.github.chrisgleissner.springbatchrest.util.core.property.JobPropertyResolvers.JobProperties;
 import static com.google.common.collect.Lists.newArrayList;
 import static java.util.Collections.synchronizedList;
 
-@Slf4j
-@Configuration
+@Configuration @RequiredArgsConstructor @Slf4j
 public class PersonJobConfig {
-
     static final String JOB_NAME = "personJob";
     static final String LAST_NAME_PREFIX = "lastNamePrefix";
 
-    @Autowired
-    JobBuilderFactory jobs;
-
-    @Autowired
-    StepBuilderFactory steps;
-
-    @Autowired
-    private AdHocScheduler adHocScheduler;
+    private final JobBuilderFactory jobs;
+    private final StepBuilderFactory steps;
+    private final AdHocScheduler adHocScheduler;
+    private final Environment environment;
 
     @Bean
     Job personJob(@Qualifier("personStep") Step personStep) {
@@ -81,24 +77,25 @@ FlatFileItemReader<Person> personReader() {
                 .build();
     }
 
-    @Bean
-    ItemProcessor personProcessor(@Qualifier("personNameCaseChange") ItemProcessor personNameCaseChange) {
+    @Bean @StepScope
+    ItemProcessor personProcessor(
+            @Qualifier("personNameCaseChange") ItemProcessor personNameCaseChange,
+            @Value("#{jobParameters['" + LAST_NAME_PREFIX + "']}") String lastNamePrefix) {
         CompositeItemProcessor p = new CompositeItemProcessor();
-        p.setDelegates(newArrayList(personNameFilter(), personNameCaseChange));
+        p.setDelegates(newArrayList(
+                personNameFilter(Optional.ofNullable(lastNamePrefix).orElseGet(() -> environment.getProperty(LAST_NAME_PREFIX))),
+                personNameCaseChange));
         return p;
     }
 
-    @Bean
-    ItemProcessor personNameFilter() {
+    private ItemProcessor personNameFilter(String lastNamePrefix) {
         return new FunctionItemProcessor<Person, Person>(p -> {
-            String lastNamePrefix = JobProperties.of(PersonJobConfig.JOB_NAME).getProperty(LAST_NAME_PREFIX);
             log.info("Last name prefix: {}", lastNamePrefix);
             return p.lastName != null && p.lastName.startsWith(lastNamePrefix) ? p : null;
         });
     }
 
-    @StepScope
-    @Bean
+    @Bean @StepScope
     ItemProcessor personNameCaseChange(@Value("#{jobParameters['upperCase']}") Boolean upperCaseParam) {
         boolean upperCase = upperCaseParam == null ? false : upperCaseParam;
         log.info("personNameCaseChange(upperCase={})", upperCase);

example/quartz-api/src/test/java/com/github/chrisgleissner/springbatchrest/example/quartz/PersonJobTest.java

@@ -23,18 +23,10 @@
 @RunWith(SpringRunner.class)
 @SpringBootTest(webEnvironment = DEFINED_PORT)
 public class PersonJobTest {
-
-    @LocalServerPort
-    private int port;
-
-    @Autowired
-    private TestRestTemplate restTemplate;
-
-    @Autowired
-    private PersonJobConfig.CacheItemWriter<PersonJobConfig.Person> cacheItemWriter;
-
-    @Autowired
-    private JobRegistry jobRegistry;
+    @LocalServerPort private int port;
+    @Autowired private TestRestTemplate restTemplate;
+    @Autowired private PersonJobConfig.CacheItemWriter<PersonJobConfig.Person> cacheItemWriter;
+    @Autowired private JobRegistry jobRegistry;
 
     @Test
     public void canStartJob() throws NoSuchJobException {
@@ -58,16 +50,11 @@ public void canStartJob() throws NoSuchJobException {
     }
 
     private JobExecution startJob(Optional<String> lastNamePrefix, Optional<Boolean> upperCase) {
-        JobConfig.JobConfigBuilder jobConfigBuilder = JobConfig.builder()
-                .name(PersonJobConfig.JOB_NAME).asynchronous(false);
-        if (lastNamePrefix.isPresent())
-            jobConfigBuilder.property(PersonJobConfig.LAST_NAME_PREFIX, lastNamePrefix.get());
-        if (upperCase.isPresent())
-            jobConfigBuilder.property("upperCase", "" + upperCase.get());
-        JobConfig jobConfig = jobConfigBuilder.build();
-
+        JobConfig.JobConfigBuilder jobConfigBuilder = JobConfig.builder().name(PersonJobConfig.JOB_NAME).asynchronous(false);
+        lastNamePrefix.ifPresent(s -> jobConfigBuilder.property(PersonJobConfig.LAST_NAME_PREFIX, s));
+        upperCase.ifPresent(aBoolean -> jobConfigBuilder.property("upperCase", "" + aBoolean));
         ResponseEntity<JobExecutionResource> responseEntity = restTemplate.postForEntity("http://localhost:" + port + "/jobExecutions",
-                jobConfig, JobExecutionResource.class);
+                jobConfigBuilder.build(), JobExecutionResource.class);
         assertThat(responseEntity.getStatusCode()).isEqualTo(HttpStatus.OK);
         return responseEntity.getBody().getJobExecution();
     }