41cbb93142
Move away from the Neo4j OGM usage because Spring Data Neo4j fits better in the ecosystem, spring-batch is settled in. Previously there was no visible difference to users because Spring Data Neo4j was based on Neo4j OGM which isn't the case anymore.
111 lines
3.6 KiB
Markdown
111 lines
3.6 KiB
Markdown
# spring-batch-neo4j
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This extension contains an `ItemReader` and `ItemWriter` implementations for [Neo4j](https://neo4j.com).
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# Usage example
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The `Neo4jItemReader` can be configured as follows:
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```java
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Neo4jItemReader<User> reader = new Neo4jItemReaderBuilder<User>()
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.neo4jTemplate(neo4jTemplate)
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.name("userReader")
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.statement(Cypher.match(userNode).returning(userNode))
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.targetType(User.class)
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.pageSize(50)
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.build();
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```
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The `Neo4jItemWriter` can be configured as follows:
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```java
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Neo4jItemWriter<User> writer = new Neo4jItemWriterBuilder<User>()
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.neo4jTemplate(neo4jTemplate)
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.neo4jDriver(driver)
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.neo4jMappingContext(mappingContext)
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.build();
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```
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## Minimal Spring Boot example
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Additional to the already existing dependencies in a new Spring Boot application,
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`spring-boot-starter-data-neo4j`, `spring-batch-neo4j` and the `spring-boot-starter-batch` are needed
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but `spring-jdbc` and `spring-boot-starter-jdbc` must be explicitly excluded.
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The exclusions are mandatory to avoid any need for JDBC-based connections, like JDBC URI etc.
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See the following _build.gradle_ dependency definition for a minimal example.
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```groovy
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dependencies {
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implementation ('org.springframework.boot:spring-boot-starter-batch') {
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exclude group: 'org.springframework', module: 'spring-jdbc'
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exclude group: 'org.springframework.boot', module: 'spring-boot-starter-jdbc'
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}
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// current development version 0.2.0-SNAPSHOT
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implementation 'org.springframework.batch.extensions:spring-batch-neo4j'
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implementation 'org.springframework.boot:spring-boot-starter-data-neo4j'
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testImplementation 'org.springframework.boot:spring-boot-starter-test'
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testImplementation 'org.springframework.batch:spring-batch-test'
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}
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```
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An example of the usage can be seen in the following example, implementing the `CommandLineRunner` interface.
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```java
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@SpringBootApplication
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public class TestSpringBatchApplication implements CommandLineRunner {
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// those dependencies are created by Spring Boot's
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// spring-data-neo4j autoconfiguration
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@Autowired
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private Driver driver;
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@Autowired
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private Neo4jMappingContext mappingContext;
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@Autowired
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private Neo4jTemplate neo4jTemplate;
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public static void main(String[] args) {
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SpringApplication.run(TestSpringBatchApplication.class, args);
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}
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@Override
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public void run(String... args) {
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// writing
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Neo4jItemWriter<User> writer = new Neo4jItemWriterBuilder<User>()
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.neo4jTemplate(neo4jTemplate)
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.neo4jDriver(driver)
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.neo4jMappingContext(mappingContext)
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.build();
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writer.write(Chunk.of(new User("id1", "ab"), new User("id2", "bb")));
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// reading
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org.neo4j.cypherdsl.core.Node userNode = Cypher.node("User");
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Neo4jItemReader<User> reader = new Neo4jItemReaderBuilder<User>()
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.neo4jTemplate(neo4jTemplate)
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.name("userReader")
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.statement(Cypher.match(userNode).returning(userNode))
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.targetType(User.class)
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.build();
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List<User> allUsers = new ArrayList<>();
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User user = null;
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while ((user = reader.read()) != null) {
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System.out.printf("Found user: %s%n", user.name);
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allUsers.add(user);
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}
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// deleting
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writer.setDelete(true);
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writer.write(Chunk.of(allUsers.toArray(new User[]{})));
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}
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@Node("User")
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public static class User {
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@Id public final String id;
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public final String name;
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public User(String id, String name) {
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this.id = id;
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this.name = name;
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}
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}
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}
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``` |