Question

我需要通过spring批处理作业执行来处理flatfile。我从文件夹中获取需要处理的文件列表。请让我知道如何做到这一点。

例如：
我在一个文件夹中有player.csv和player1.csv以及player2.csv。我在列表中有这些文件名。如果我可以为Jobparameters输入所有这些文件名，请告诉我，以便我可以执行一个Job？

JobParameters jobParameters = new JobParametersBuilder().addString("input.file", "file:player.csv").toJobParameters();
JobExecution execution = jobLauncher.run(job,jobParameters);
assertEquals(ExitStatus.COMPLETED, execution.getExitStatus());

Answer 1

有几种方法可以做到这一点; 1.创建一个作业来一次处理一个文件并让你的作业发起者迭代文件并触发作业，一次只传入一个文件 2.在你的工作中创建一个'循环'来检查值并处理每个文件

这是后一种选择的一个例子;

首先是作业配置 - 它使用决策程序为要处理的文件构建执行上下文值。如果没有更多文件（来自jobParameter），则完成

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:batch="http://www.springframework.org/schema/batch"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/batch http://www.springframework.org/schema/batch/spring-batch.xsd">

    <batch:job id="multipleFileProcess">
        <batch:decision decider="decider" id="multipleFileProcess.decider">
            <batch:next on="UNKNOWN" to="multipleFileProcess.step1"/>
            <batch:end on="COMPLETED"/>
        </batch:decision>
        <batch:step id="multipleFileProcess.step1" next="multipleFileProcess.decider">
            <batch:tasklet>
                <batch:chunk reader="fileReader" writer="outWriter" commit-interval="10"/>
            </batch:tasklet>
        </batch:step>
        <batch:validator>
            <bean class="org.springframework.batch.core.job.DefaultJobParametersValidator">
                <property name="requiredKeys" value="input.files"/>
            </bean>         
        </batch:validator>
    </batch:job>


    <bean id="fileReader"
        class="org.springframework.batch.item.file.FlatFileItemReader" scope="step">
        <property name="lineMapper" ref="lineMapper"/>
        <property name="resource" value="file:#{jobExecutionContext['input.file']}"/>
    </bean>

    <bean id="lineMapper"
        class="org.springframework.batch.item.file.mapping.PassThroughLineMapper"/>


    <bean id="transactionManager"
        class="org.springframework.batch.support.transaction.ResourcelessTransactionManager">
    </bean>

    <bean id="decider" class="de.incompleteco.spring.batch.decider.FileDecision"/>

    <bean id="outWriter" class="de.incompleteco.spring.batch.item.writer.SystemOutItemWriter"/>

</beans>

这里是决策程序代码（使用内部队列 - 在执行上下文中将这个'队列'维护为一个字符串可能会更安全，你可以慢慢缩短（手动'弹出'字符串的一个条目 - 但是为了快速使用一个队列）

package de.incompleteco.spring.batch.decider;

import java.util.Arrays;
import java.util.Queue;
import java.util.concurrent.LinkedBlockingQueue;

import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.StepExecution;
import org.springframework.batch.core.job.flow.FlowExecutionStatus;
import org.springframework.batch.core.job.flow.JobExecutionDecider;

public class FileDecision implements JobExecutionDecider {

    public static final String INPUT_FILE = "input.file";
    public static final String INPUT_FILES = "input.files";
    public static final String DELIMITER = ",";

    private Queue<String> inputFiles;

    @Override
    public FlowExecutionStatus decide(JobExecution jobExecution,StepExecution stepExecution) {
        //check if the jobExecution has the input.file in it's context
        if (!jobExecution.getExecutionContext().containsKey(INPUT_FILE)) {
            //build the queue
            inputFiles = new LinkedBlockingQueue<String>(Arrays.asList(jobExecution.getJobParameters().getString(INPUT_FILES).split(DELIMITER)));
        }//end if
        //pop and add
        String file = inputFiles.poll();
        if (file != null) {
            jobExecution.getExecutionContext().put(INPUT_FILE, file);
            return FlowExecutionStatus.UNKNOWN;
        }//end if
        //return 'done'
        return FlowExecutionStatus.COMPLETED;
    }

}

这里是虚拟的“作家”，将文件显示为“书面”

package de.incompleteco.spring.batch.item.writer;

import java.util.List;

import org.springframework.batch.item.ItemWriter;

public class SystemOutItemWriter implements ItemWriter<String> {

    @Override
    public void write(List<? extends String> items) throws Exception {
        for (String item : items) {
            System.out.println("this is what was received:" + item);
        }//end for
    }

}

最后进行单元测试以查看是否运行

package de.incompleteco.spring.batch;

import static org.junit.Assert.assertFalse;

import java.io.File;
import java.io.FileWriter;

import javax.annotation.Resource;

import org.junit.Rule;
import org.junit.Test;
import org.junit.rules.TemporaryFolder;
import org.junit.runner.RunWith;
import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.JobParameters;
import org.springframework.batch.core.JobParametersBuilder;
import org.springframework.batch.core.explore.JobExplorer;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import de.incompleteco.spring.batch.decider.FileDecision;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration("classpath:/META-INF/spring/*-context.xml")
public class MultipleFileProcessIntegrationTest {

    @Rule
    public TemporaryFolder folder = new TemporaryFolder();

    @Resource
    private Job job;

    @Resource
    private JobLauncher jobLauncher;

    @Resource
    private JobExplorer jobExplorer;

    @Test
    public void test() throws Exception {
        //somewhere to hold the filenames
        StringBuilder builder = new StringBuilder();
        //create 3 files
        for (int i=0;i<3;i++) {
            File file = folder.newFile("testfile" + i + ".txt");
            //write some content
            FileWriter writer = new FileWriter(file);
            writer.write("test content: " + i);
            writer.flush();
            writer.close();
            //add the filename
            if (i > 0) {
                builder.append(FileDecision.DELIMITER);
            }//end if
            builder.append(file.getAbsolutePath());
            //show it
            System.out.println(file.getAbsolutePath());
        }//end loop


        //now build the job parameters
        JobParameters parameters = new JobParametersBuilder().addString(FileDecision.INPUT_FILES,builder.toString()).toJobParameters();
        //execution
        JobExecution execution = jobLauncher.run(job,parameters);
        //check
        while (jobExplorer.getJobExecution(execution.getId()).isRunning()) {
            Thread.sleep(100);
        }//end while
        //load
        execution = jobExplorer.getJobExecution(execution.getId());
        //check
        assertFalse(execution.getStatus().isUnsuccessful());
    }

}

春季批处理作业执行的资源列表

1 个答案: