[SpringBatch的新功能]我试图使用Spring Boot创建一个作业，该作业从MongoDB中读取名称，转换为小写字母，然后输出为CSV文件。我的读取器和处理器正在工作，而写入器却没有。
我的代码如下。
配置文件：
package bbye;
import java.util.HashMap;
import java.util.Map;
import javax.sql.DataSource;
import org.springframework.batch.core.Job;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.core.launch.support.RunIdIncrementer;
import org.springframework.batch.item.data.MongoItemReader;
import org.springframework.batch.item.data.builder.MongoItemReaderBuilder;
import org.springframework.batch.item.file.FlatFileItemWriter;
import org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor;
import org.springframework.batch.item.file.transform.DelimitedLineAggregator;
import org.springframework.batch.item.file.transform.FieldExtractor;
import org.springframework.batch.item.file.transform.LineAggregator;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.data.domain.Sort;
import org.springframework.data.mongodb.core.MongoTemplate;
import hello.Person;
@Configuration
@EnableBatchProcessing
public class BatchConfigProcessing {
@Autowired
public JobBuilderFactory jobBuilderFactory;
@Autowired
public StepBuilderFactory stepBuilderFactory;
@Autowired
private MongoTemplate mongoTemplate;
private String readQuery = "{}";
// tag::readerwriterprocessor[]
@Bean
public MongoItemReader<Person> readMongo(DataSource dataSource) {
return new MongoItemReaderBuilder<Person>()
.name("mongoDocReader")
.jsonQuery(readQuery)
.targetType(Person.class)
.sorts(sort())
.template(mongoTemplate)
.collection("people")
.build();
}
@Bean
public PersonDocProcessor processor() {
return new PersonDocProcessor();
}
@Bean
public FlatFileItemWriter<Person> writer() {
/*FlatFileItemWriterBuilder<Person> writePerson = new FlatFileItemWriterBuilder<Person>();
writePerson.name("personDocWriter");
writePerson.resource(new ClassPathResource("PersonExtracted.csv"));
writePerson.lineAggregator(new DelimitedLineAggregator<Person>());
writePerson.shouldDeleteIfExists(true);
writePerson.build();*/
FlatFileItemWriter<Person> fileWriter = new FlatFileItemWriter<>();
fileWriter.setName("csvWriter");
fileWriter.setResource(new ClassPathResource("PersonExtracted.csv"));
fileWriter.setLineAggregator(lineAggregator());
fileWriter.setForceSync(true);
fileWriter.close();
return fileWriter;
}
// end::readerwriterprocessor[]
// tag::jobstep[]
@Bean
public Job exportUserJob(FileUploadNotificationListener listener, Step step1) {
return jobBuilderFactory.get("exportUserJob")
.incrementer(new RunIdIncrementer())
.listener(listener)
.flow(step1)
.end()
.build();
}
@Bean
public Step step2(MongoItemReader<Person> reader) {
return stepBuilderFactory.get("step2")
.<Person, Person> chunk(10)
.reader(reader)
.processor(processor())
.writer(writer())
.build();
}
// end::jobstep[]
public FieldExtractor<Person> fieldExtractor()
{
BeanWrapperFieldExtractor<Person> extractor = new BeanWrapperFieldExtractor<>();
extractor.setNames( new String[] { "firstName",
"lastName"});
return extractor;
}
public LineAggregator<Person> lineAggregator() {
DelimitedLineAggregator<Person> la = new DelimitedLineAggregator<Person>();
la.setDelimiter(",");
la.setFieldExtractor(fieldExtractor());
return la;
}
public Map<String, Sort.Direction> sort(){
String firstName = "firstName";
Map<String, Sort.Direction> sortMap = new HashMap();
sortMap.put(firstName, Sort.DEFAULT_DIRECTION);
return sortMap;
}
}
处理器文件
package bbye;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.batch.item.ItemProcessor;
import org.springframework.stereotype.Component;
import hello.Person;
@Component
public class PersonDocProcessor implements ItemProcessor<Person, Person> {
private static final Logger log = LoggerFactory.getLogger(PersonDocProcessor.class);
@Override
public Person process(final Person person) throws Exception {
final String firstName = person.getFirstName().toLowerCase();
final String lastName = person.getLastName().toLowerCase();
final Person transformedPerson = new Person(firstName, lastName);
log.info("Converting (" + person + ") into (" + transformedPerson + ")");
return transformedPerson;
}
}
Listener
package bbye;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.JobExecutionListener;
import org.springframework.stereotype.Component;
@Component
public class FileUploadNotificationListener implements JobExecutionListener {
@Override
public void beforeJob(JobExecution jobExecution) {
System.out.println("===== listening for job - mongoReader - fileWriter ====");
}
@Override
public void afterJob(JobExecution jobExecution) {
System.out.println("==== file write job completed =====");
}
}
此人是一个简单的POJO。带有和不带有手动文件创建的堆栈跟踪如下：
org.springframework.batch.item.ItemStreamException: Could not convert resource to file: [class path resource [PersonExtracted.csv]]
at org.springframework.batch.item.file.FlatFileItemWriter.getOutputState(FlatFileItemWriter.java:399) ~[spring-batch-infrastructure-4.0.1.RELEASE.jar:4.0.1.RELEASE]
at org.springframework.batch.item.file.FlatFileItemWriter.open(FlatFileItemWriter.java:337) ~[spring-batch-infrastructure-4.0.1.RELEASE.jar:4.0.1.RELEASE]
........
Caused by: java.io.FileNotFoundException: class path resource [PersonExtracted.csv] cannot be resolved to URL because it does not exist
:: Spring Boot :: (v2.0.2.RELEASE)
2018-06-19 11:35:17.663 INFO 25136 --- [ main] hello.Application : Starting Application on MyPC with PID 25136 (C:\eclipse-workspace\gs-batch-processing-master\complete\target\classes started by shristi in C:\eclipse-workspace\gs-batch-processing-master\complete)
2018-06-19 11:35:17.666 INFO 25136 --- [ main] hello.Application : No active profile set, falling back to default profiles: default
2018-06-19 11:35:17.689 INFO 25136 --- [ main] s.c.a.AnnotationConfigApplicationContext : Refreshing org.springframework.context.annotation.AnnotationConfigApplicationContext@15bb6bea: startup date [Tue Jun 19 11:35:17 EDT 2018]; root of context hierarchy
2018-06-19 11:35:18.135 INFO 25136 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting...
2018-06-19 11:35:18.136 WARN 25136 --- [ main] com.zaxxer.hikari.util.DriverDataSource : Registered driver with driverClassName=org.hsqldb.jdbcDriver was not found, trying direct instantiation.
2018-06-19 11:35:18.282 INFO 25136 --- [ main] com.zaxxer.hikari.pool.PoolBase : HikariPool-1 - Driver does not support get/set network timeout for connections. (feature not supported)
2018-06-19 11:35:18.284 INFO 25136 --- [ main] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed.
2018-06-19 11:35:18.293 INFO 25136 --- [ main] o.s.jdbc.datasource.init.ScriptUtils : Executing SQL script from URL [file:/C:/eclipse-workspace/gs-batch-processing-master/complete/target/classes/schema-all.sql]
2018-06-19 11:35:18.297 INFO 25136 --- [ main] o.s.jdbc.datasource.init.ScriptUtils : Executed SQL script from URL [file:/C:/eclipse-workspace/gs-batch-processing-master/complete/target/classes/schema-all.sql] in 4 ms.
2018-06-19 11:35:18.518 INFO 25136 --- [ main] org.mongodb.driver.cluster : Cluster created with settings {hosts=[localhost:27017], mode=SINGLE, requiredClusterType=UNKNOWN, serverSelectionTimeout='30000 ms', maxWaitQueueSize=500}
2018-06-19 11:35:18.552 INFO 25136 --- [localhost:27017] org.mongodb.driver.connection : Opened connection [connectionId{localValue:1, serverValue:140}] to localhost:27017
2018-06-19 11:35:18.554 INFO 25136 --- [localhost:27017] org.mongodb.driver.cluster : Monitor thread successfully connected to server with description ServerDescription{address=localhost:27017, type=STANDALONE, state=CONNECTED, ok=true, version=ServerVersion{versionList=[3, 6, 0]}, minWireVersion=0, maxWireVersion=6, maxDocumentSize=16777216, logicalSessionTimeoutMinutes=30, roundTripTimeNanos=1438717}
2018-06-19 11:35:18.723 INFO 25136 --- [ main] o.s.b.c.r.s.JobRepositoryFactoryBean : No database type set, using meta data indicating: HSQL
2018-06-19 11:35:18.770 INFO 25136 --- [ main] o.s.b.c.l.support.SimpleJobLauncher : No TaskExecutor has been set, defaulting to synchronous executor.
2018-06-19 11:35:18.778 INFO 25136 --- [ main] o.s.jdbc.datasource.init.ScriptUtils : Executing SQL script from class path resource [org/springframework/batch/core/schema-hsqldb.sql]
2018-06-19 11:35:18.781 INFO 25136 --- [ main] o.s.jdbc.datasource.init.ScriptUtils : Executed SQL script from class path resource [org/springframework/batch/core/schema-hsqldb.sql] in 3 ms.
2018-06-19 11:35:18.870 INFO 25136 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2018-06-19 11:35:18.871 INFO 25136 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Bean with name 'dataSource' has been autodetected for JMX exposure
2018-06-19 11:35:18.873 INFO 25136 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Located MBean 'dataSource': registering with JMX server as MBean [com.zaxxer.hikari:name=dataSource,type=HikariDataSource]
2018-06-19 11:35:18.880 INFO 25136 --- [ main] hello.Application : Started Application in 1.357 seconds (JVM running for 2.284)
2018-06-19 11:35:18.881 INFO 25136 --- [ main] o.s.b.a.b.JobLauncherCommandLineRunner : Running default command line with: []
2018-06-19 11:35:18.908 INFO 25136 --- [ main] o.s.b.c.l.support.SimpleJobLauncher : Job: [FlowJob: [name=exportUserJob]] launched with the following parameters: [{run.id=1}]
===== listening for job - mongoReader - fileWriter ====
2018-06-19 11:35:18.917 INFO 25136 --- [ main] o.s.batch.core.job.SimpleStepHandler : Executing step: [step2]
2018-06-19 11:35:18.995 INFO 25136 --- [ main] org.mongodb.driver.connection : Opened connection [connectionId{localValue:2, serverValue:141}] to localhost:27017
2018-06-19 11:35:19.022 INFO 25136 --- [ main] bbye.PersonDocProcessor : Converting (firstName: ALICE, lastName: WONDERLAND) into (firstName: alice, lastName: wonderland)
2018-06-19 11:35:19.022 INFO 25136 --- [ main] bbye.PersonDocProcessor : Converting (firstName: FIRSTNAME, lastName: LASTNAME) into (firstName: firstname, lastName: lastname)
2018-06-19 11:35:19.022 INFO 25136 --- [ main] bbye.PersonDocProcessor : Converting (firstName: JANE, lastName: DOE) into (firstName: jane, lastName: doe)
2018-06-19 11:35:19.022 INFO 25136 --- [ main] bbye.PersonDocProcessor : Converting (firstName: JOHN, lastName: DOE) into (firstName: john, lastName: doe)
2018-06-19 11:35:19.022 INFO 25136 --- [ main] bbye.PersonDocProcessor : Converting (firstName: MARK, lastName: WINN) into (firstName: mark, lastName: winn)
==== file write job completed =====
2018-06-19 11:35:19.031 INFO 25136 --- [ main] o.s.b.c.l.support.SimpleJobLauncher : Job: [FlowJob: [name=exportUserJob]] completed with the following parameters: [{run.id=1}] and the following status: [COMPLETED]
2018-06-19 11:35:19.032 INFO 25136 --- [ Thread-2] s.c.a.AnnotationConfigApplicationContext : Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@15bb6bea: startup date [Tue Jun 19 11:35:17 EDT 2018]; root of context hierarchy
2018-06-19 11:35:19.033 INFO 25136 --- [ Thread-2] o.s.j.e.a.AnnotationMBeanExporter : Unregistering JMX-exposed beans on shutdown
2018-06-19 11:35:19.034 INFO 25136 --- [ Thread-2] o.s.j.e.a.AnnotationMBeanExporter : Unregistering JMX-exposed beans
2018-06-19 11:35:19.035 INFO 25136 --- [ Thread-2] org.mongodb.driver.connection : Closed connection [connectionId{localValue:2, serverValue:141}] to localhost:27017 because the pool has been closed.
2018-06-19 11:35:19.036 INFO 25136 --- [ Thread-2] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown initiated...
2018-06-19 11:35:19.037 INFO 25136 --- [ Thread-2] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Shutdown completed.
答案 0 :(得分：1)
我认为我们应该使用FileSystemResource而不是ClassPathResource。您可以尝试告诉我们吗？
答案 1 :(得分：0)
回答问题。事实证明，编写者的工作正常，但我查看的是错误的文件。 使用 ClassPathResource 时，将在 target / classes 目录下创建和更新文件。但是，我正在查看 src / main / resources 目录下的PersonExtracted.csv，该目录从未更新。
如果我指定 FileSystemResource ，则会在指定位置创建并更新文件。