spring batch架构 spring batch 教程

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IT剑客风云 2023-10-20 08:36:47

文章标签 spring batch架构 spring xml java 文章分类 架构后端开发

Spring batch 是一个开源的批处理框架.执行一系列的任务. 在 spring batch 中一个job 是由许多 step 组成的。而每一个 step 又是由 READ-PROCESS-WRITE task或者单个 task 组成。

1. "READ-PROCESS-WRITE" 处理，根据字面意思理解就可以:
READ 就是从资源文件里面读取数据，比如从xml文件,csv文件,数据库中读取数据.
PROCESS 就是处理读取的数据
WRITE 就是将处理过的数据写入到其他资源文件中去，可以是XML,CSV,或者数据库.
比如：从CSV文件中读取数据，经过处理之后，保存到数据库. spring batch 提供了很多类去处理这方面的东西。

2.单个task, 也就是处理单个任务。比如在一个step 开始之前或者完成之后清除资源文件等.
3.许多个step 组成在一起，就组成了一个job. 所以他们之间的关系，就如同下面的描述:

一个 job = 很多steps
一个step = 一个READ-PROCESS-WRITE 或者 一个task.
同样一个job = step1 -->step2--step3 这样链表形式的组成.

Spring batch 例子

考虑如下一个批处理的例子,看起来有点啰嗦，只是为了说明用途:

1. step1 : 从 A 文件夹中读取csv 文件，处理之后，写入到B文件夹中(READ-PROCESS-WRITE)

2. step2 : 从 B 文件夹中读取CSV文件，处理之后，存储到数据库中(READ-PROCESS-WRITE).

3. step3 : 删除B文件夹下的CSV文件。(用到单个task)

4. step4 : 从数据库读取数据，处理之后，生成XML报表文件(READ-PROCESS-WRITE).

5. step5 : 读取XML报表,并发送EMAIL给管理员(用到单个task)

用spring batch 我们可以如下定义这个job:

<job id="abcJob" xmlns="http://www.springframework.org/schema/batch">
    <step id="step1" next="step2">
      <tasklet>
        <chunk reader="cvsItemReader" writer="cvsItemWriter"  
                    processor="itemProcesser" commit-interval="1" />
      </tasklet>
    </step>
    <step id="step2" next="step3">
      <tasklet>
        <chunk reader="cvsItemReader" writer="databaseItemWriter"  
                    processor="itemProcesser" commit-interval="1" />
      </tasklet>
    </step>
    <step id="step3" next="step4">
      <tasklet ref="fileDeletingTasklet" />
    </step>
    <step id="step4" next="step5">
      <tasklet>
        <chunk reader="databaseItemReader" writer="xmlItemWriter"  
                    processor="itemProcesser" commit-interval="1" />
      </tasklet>
    </step>
    <step id="step5">
        <tasklet ref="sendingEmailTasklet" />
    </step>
  </job>

整个 job 的执行是存储在数据库中的，所以即使是某一个step出错失败，也不需要全部从头开始执行这个job.下面是一个真正的入门教程例子.

采用 jar包如下:

spring-batch-2.2.3 以上版本，但是我在2.2.3版本中发现 org/springframework/batch/core/schema-mysql.sql 里面的的mysql 创建表的语句是有问题的，也就是少了“," 号导致的问题( NOT NULL, 后面几个创建表的语句NOT NULL 后面少了逗号)，当然你可以自己修改后再执行，执行完毕后有如下几个表:

xstream-1.3.jar 必须的。

jettison-1.3.3.jar也是必须的, 下载地址：

http://jettison.codehaus.org/Download

否则会出现

java.lang.NoClassDefFoundError: org/codehaus/jettison/mapped/MappedXMLOutputFactory错误。

另外我用的spring 是 3.1 版本的，可以下载相关jar包，还有apache common 相关jar包就可以了。

mysql-connect-java-5.1.jar 连接mysql 数据库用的。

假设要将如下 csv 文件读取出来处理之后，写入到一个xml文件之中.

,"213,100",980,"mkyong", 29/7/2013
,"320,200",1080,"staff 1", 30/7/2013
,"342,197",1200,"staff 2", 31/7/2013

用 FlatFileItemReader 去读取CSV 文件, 用 itemProcessor 去处理数据，用 StaxEventItemWriter 去写数据

job 的定义如下(job-hello-world.xml):

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:batch="http://www.springframework.org/schema/batch" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/batch
        http://www.springframework.org/schema/batch/spring-batch-2.2.xsd
        http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans-3.1.xsd
    ">
    <import resource="../config/context.xml" />
    <import resource="../config/database.xml" />
    <bean id="report" class="yihaomen.model.Report" scope="prototype" />
    <bean id="itemProcessor" class="yihaomen.CustomItemProcessor" />
    <batch:job id="helloWorldJob">
        <batch:step id="step1">
            <batch:tasklet>
                <batch:chunk reader="cvsFileItemReader" writer="xmlItemWriter" processor="itemProcessor"
                    commit-interval="10">
                </batch:chunk>
            </batch:tasklet>
        </batch:step>
    </batch:job>
    <bean id="cvsFileItemReader" class="org.springframework.batch.item.file.FlatFileItemReader">
        <property name="resource" value="classpath:cvs/input/report.csv" />
        <property name="lineMapper">
            <bean class="org.springframework.batch.item.file.mapping.DefaultLineMapper">
                <property name="lineTokenizer">
                    <bean
                        class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer">
                        <property name="names" value="id,sales,qty,staffName,date" />
                    </bean>
                </property>
                <property name="fieldSetMapper">
                    <bean class="yihaomen.ReportFieldSetMapper" />
                    
                    <!-- if no data type conversion, use BeanWrapperFieldSetMapper to map by name
                    <bean
                        class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper">
                        <property name="prototypeBeanName" value="report" />
                    </bean>
                     -->
                </property>
            </bean>
        </property>
    </bean>
    <bean id="xmlItemWriter" class="org.springframework.batch.item.xml.StaxEventItemWriter">
        <property name="resource" value="file:xml/outputs/report.xml" />
        <property name="marshaller" ref="reportMarshaller" />
        <property name="rootTagName" value="report" />
    </bean>
    <bean id="reportMarshaller" class="org.springframework.oxm.jaxb.Jaxb2Marshaller">
        <property name="classesToBeBound">
            <list>
                <value>yihaomen.model.Report</value>
            </list>
        </property>
    </bean>
</beans>

映射csv文件到 Report 对象并写XML文件 (通过 jaxb annotations).

package yihaomen.model;
import java.math.BigDecimal;
import java.util.Date;
import javax.xml.bind.annotation.XmlAttribute;
import javax.xml.bind.annotation.XmlElement;
import javax.xml.bind.annotation.XmlRootElement;
@XmlRootElement(name = "record")
public class Report {
    private int id;
    private BigDecimal sales;
    private int qty;
    private String staffName;
    private Date date;
    @XmlAttribute(name = "id")
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    @XmlElement(name = "sales")
    public BigDecimal getSales() {
        return sales;
    }
    public void setSales(BigDecimal sales) {
        this.sales = sales;
    }
    @XmlElement(name = "qty")
    public int getQty() {
        return qty;
    }
    public void setQty(int qty) {
        this.qty = qty;
    }
    @XmlElement(name = "staffName")
    public String getStaffName() {
        return staffName;
    }
    public void setStaffName(String staffName) {
        this.staffName = staffName;
    }
    public Date getDate() {
        return date;
    }
    public void setDate(Date date) {
        this.date = date;
    }
    @Override
    public String toString() {
        return "Report [id=" + id + ", sales=" + sales + ", qty=" + qty + ", staffName=" + staffName + "]";
    }
}

为了转换日期,用了自定义的 FieldSetMapper. 如果没有数据需要转换, BeanWrapperFieldSetMapper 通过名称name 去自动映射值。

package yihaomen;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import org.springframework.batch.item.file.mapping.FieldSetMapper;
import org.springframework.batch.item.file.transform.FieldSet;
import org.springframework.validation.BindException;
import yihaomen.model.Report;
public class ReportFieldSetMapper implements FieldSetMapper<Report> {
    private SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");
    
    @Override
    public Report mapFieldSet(FieldSet fieldSet) throws BindException {
        
        Report report = new Report();
        report.setId(fieldSet.readInt(0));
        report.setSales(fieldSet.readBigDecimal(1));
        report.setQty(fieldSet.readInt(2));
        report.setStaffName(fieldSet.readString(3));
        
        //default format yyyy-MM-dd
        //fieldSet.readDate(4);
        String date = fieldSet.readString(4);
        try {
            report.setDate(dateFormat.parse(date));
        } catch (ParseException e) {
            e.printStackTrace();
        }
        
        return report;
        
    }
}

在写入数据之前调用itemProcessor 处理数据

package yihaomen;
import org.springframework.batch.item.ItemProcessor;
import yihaomen.model.Report;
public class CustomItemProcessor implements ItemProcessor<Report, Report> {
    @Override
    public Report process(Report item) throws Exception {
        
        System.out.println("Processing..." + item);
        return item;
    }
}

spring 配置文件和数据库配置文件

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="
        http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd">
 
    <!-- stored job-meta in memory -->
    <!--  
    <bean id="jobRepository"
        class="org.springframework.batch.core.repository.support.MapJobRepositoryFactoryBean">
        <property name="transactionManager" ref="transactionManager" />
    </bean>
      -->
 
      <!-- stored job-meta in database -->
    <bean id="jobRepository"
        class="org.springframework.batch.core.repository.support.JobRepositoryFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="transactionManager" ref="transactionManager" />
        <property name="databaseType" value="mysql" />
    </bean>
 
    <bean id="transactionManager"
        class="org.springframework.batch.support.transaction.ResourcelessTransactionManager" />
 
    <bean id="jobLauncher"
        class="org.springframework.batch.core.launch.support.SimpleJobLauncher">
        <property name="jobRepository" ref="jobRepository" />
    </bean>
 
</beans>

<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:jdbc="http://www.springframework.org/schema/jdbc" 
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
        http://www.springframework.org/schema/jdbc 
        http://www.springframework.org/schema/jdbc/spring-jdbc-3.2.xsd">
 
        <!-- connect to MySQL database -->
    <bean id="dataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource">
        <property name="driverClassName" value="com.mysql.jdbc.Driver" />
        <property name="url" value="jdbc:mysql://localhost:3306/test" />
        <property name="username" value="root" />
        <property name="password" value="" />
    </bean>
 
    <bean id="transactionManager"
        class="org.springframework.batch.support.transaction.ResourcelessTransactionManager" />
 
    <!-- create job-meta tables automatically -->
    <jdbc:initialize-database data-source="dataSource">
        <jdbc:script location="org/springframework/batch/core/schema-drop-mysql.sql" />
        <jdbc:script location="org/springframework/batch/core/schema-mysql.sql" />
    </jdbc:initialize-database>
 
</beans>

运行程序

package yihaomen;
import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.JobParameters;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class App {
    public static void main(String[] args) {
        String[] springConfig  = 
            {    
                "spring/batch/jobs/job-hello-world.xml" 
            };
        
        ApplicationContext context = 
                new ClassPathXmlApplicationContext(springConfig);
        
        JobLauncher jobLauncher = (JobLauncher) context.getBean("jobLauncher");
        Job job = (Job) context.getBean("helloWorldJob");
        try {
            JobExecution execution = jobLauncher.run(job, new JobParameters());
            System.out.println("Exit Status : " + execution.getStatus());
        } catch (Exception e) {
            e.printStackTrace();
        }
        System.out.println("Done");
    }
}

运行结果：

十二月 03, 2013 8:56:24 下午 org.springframework.batch.core.launch.support.SimpleJobLauncher$1 run
INFO: Job: [FlowJob: [name=helloWorldJob]] launched with the following parameters: [{}]
十二月 03, 2013 8:56:24 下午 org.springframework.batch.core.job.SimpleStepHandler handleStep
INFO: Executing step: [step1]
Processing...Report [id=1001, sales=213100, qty=980, staffName=yihaomen]
Processing...Report [id=1002, sales=320200, qty=1080, staffName=staff 1]
Processing...Report [id=1003, sales=342197, qty=1200, staffName=staff 2]
十二月 03, 2013 8:56:25 下午 org.springframework.batch.core.launch.support.SimpleJobLauncher$1 run
INFO: Job: [FlowJob: [name=helloWorldJob]] completed with the following parameters: [{}] and the following status: [COMPLETED]
Exit Status : COMPLETED
Done

结果生成了output.xml 在你工程目录的 xml 目录下。

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