Spring Batch 之 Sample（复合格式文件的读、多文件的写）(七)

      前面关于Spring Batch的文章，讲述了SpringBatch对CSV文件的读写操作、对XML文件的操作，以及对固定长格式文件的操作。这些事例，同一个Reader读取的都是相同格式的数据，最终写入一个文件。如果遇到下面这样的数据，并想将学生信息和商品信息分类后写入两个文件，应该如何处理呢？

student,200001,ZhangSan,18,78
goodsPNH001011000200.1zhangshana2011/12/18 01:12:36
student,200002,LiSi,19,79
goodsPNH001022000300.1zhangshanb2011/12/19 01:12:36
student,200003,WangWu,20,80
goodsPNH001033000400.1zhangshanc2011/12/20 01:12:36

  * 以student开头的数据代表学生信息，以goods开头代表商品信息

这次将和大家一起探讨Spring Batch读取复合格式的数据，然后写入不同的文件的处理方式。

      工程结构如下图：

       applicationContext.xml和log4j.xml前文已经叙述过，在此不做赘述。

      本实例的核心配置文件batch.mxl内容如下：

<?xml version="1.0" encoding="UTF-8"?>
<bean:beans xmlns="http://www.springframework.org/schema/batch"
    xmlns:bean="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:p="http://www.springframework.org/schema/p" xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context"
    xmlns:util="http://www.springframework.org/schema/util"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd  
http://www.springframework.org/schema/tx 
http://www.springframework.org/schema/tx/spring-tx-3.0.xsd  
http://www.springframework.org/schema/aop 
http://www.springframework.org/schema/aop/spring-aop-3.0.xsd  
http://www.springframework.org/schema/context 
http://www.springframework.org/schema/context/spring-context-2.5.xsd
http://www.springframework.org/schema/batch 
http://www.springframework.org/schema/batch/spring-batch-2.1.xsd 
http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd">

    <bean:import resource="applicationContext.xml" />
    <!-- Job的配置信息 -->
    <job id="multiTypeSingleFileJob">
        <step id="xmlFileReadAndWriterStep">
            <tasklet>
                <chunk reader="multiTypesItemReader" writer="multiTypesItemWriter"
                    commit-interval="1">
                    <streams>
                        <stream ref="studentWriter" />
                        <stream ref="goodsWriter" />
                    </streams>
                </chunk>
            </tasklet>
        </step>
    </job>

    <!-- 不同格式数据的文件读取 -->
    <bean:bean id="multiTypesItemReader"
        class="org.springframework.batch.item.file.FlatFileItemReader" scope="step">
        <bean:property name="resource"
            value="file:#{jobParameters['inputFilePath']}" />
        <bean:property name="lineMapper">
            <bean:bean
class="org.springframework.batch.item.file.mapping.PatternMatchingCompositeLineMapper">
                <bean:property name="tokenizers">
                    <bean:map>
                        <bean:entry key="student*" value-ref="studentTokenizer" />
                        <bean:entry key="goods*" value-ref="goodsTokenizer" />
                    </bean:map>
                </bean:property>
                <bean:property name="fieldSetMappers">
                    <bean:map>
                        <bean:entry key="student*" value-ref="studentFieldSetMapper" />
                        <bean:entry key="goods*" value-ref="goodsFieldSetMapper" />
                    </bean:map>
                </bean:property>
            </bean:bean>
        </bean:property>
    </bean:bean>
    <bean:bean id="studentTokenizer"
        class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer">
        <bean:property name="delimiter" value="," />
        <bean:property name="names">
            <bean:list>
                <bean:value>student</bean:value>
                <bean:value>ID</bean:value>
                <bean:value>name</bean:value>
                <bean:value>age</bean:value>
                <bean:value>score</bean:value>
            </bean:list>
        </bean:property>
    </bean:bean>
    <bean:bean id="studentFieldSetMapper"
        class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper">
        <bean:property name="prototypeBeanName" value="student" />
        <bean:property name="distanceLimit" value="100" />
    </bean:bean>
    <!-- 学生Pojo类 -->
    <bean:bean id="student"
        class="com.wanggc.springbatch.sample.multitypessinglefile.pojo.Student"
        scope="prototype" />

    <bean:bean id="goodsTokenizer"
        class="org.springframework.batch.item.file.transform.FixedLengthTokenizer">
        <bean:property name="columns" value="6-13,14-17,18-22,23-32,33-" />
        <bean:property name="names"
            value="isin,quantity,price,customer,buyDay" />
    </bean:bean>
    <bean:bean id="goodsFieldSetMapper"
        class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper">
        <bean:property name="prototypeBeanName" value="goods" />
    </bean:bean>
    <!-- 商品Pojo类 -->
    <bean:bean id="goods"
        class="com.wanggc.springbatch.sample.multitypessinglefile.pojo.Goods"
        scope="prototype" />

    <bean:bean id="multiTypesItemWriter"
        class="com.wanggc.springbatch.sample.multitypessinglefile.MultiItemWriter">
        <bean:property name="delegates">
            <bean:list>
                <bean:ref bean="studentWriter" />
                <bean:ref bean="goodsWriter" />
            </bean:list>
        </bean:property>
    </bean:bean>
    <!-- 学生信息的写 -->
    <bean:bean id="studentWriter"
        class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step">
        <bean:property name="resource"
            value="file:#{jobParameters['outputFilePathStudent']}" />
        <bean:property name="lineAggregator">
            <bean:bean
class="org.springframework.batch.item.file.transform.FormatterLineAggregator">
                <bean:property name="fieldExtractor">
                    <bean:bean
class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor">
                        <bean:property name="names" value="ID,name,age,score" />
                    </bean:bean>
                </bean:property>
                <bean:property name="format" value="%-9s%-9s%3d%-2.0f" />
            </bean:bean>
        </bean:property>
    </bean:bean>
    <!-- 商品信息的写 -->
    <bean:bean id="goodsWriter"
        class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step">
        <bean:property name="resource"
            value="file:#{jobParameters['outputFilePathGoods']}" />
        <bean:property name="lineAggregator">
            <bean:bean
class="org.springframework.batch.item.file.transform.DelimitedLineAggregator">
                <bean:property name="fieldExtractor">
                    <bean:bean
class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor">
                        <bean:property name="names"
                            value="isin,quantity,price,customer,buyDay" />
                    </bean:bean>
                </bean:property>
            </bean:bean>
        </bean:property>
    </bean:bean>
</bean:beans>

       21-33行配置了Job的基本信息。  

      36-57行配置了Reader的基本信息。FlatFileItemReader的lineMapper属性使用SpringBatch核心类PatternMatchingCompositeLineMapper的时候，会将读取的记录按照不同的方式映射成我们的Pojo对象。当然首先我们要配置不同的tokenizers（43-48）和fieldSetMappers（49-54），并告诉它当前的记录按照那条原则去解析和映射。如45行所示，我们指定key为student*的时候，用studentTokenizer去解析成fieldset，用studentFieldSetMapper将studentTokenizer解析好的fieldset记录映射成Student对象。我们指定的key，其实也就是student开头的记录，*是通配符。PatternMatchingCompositeLineMapper支持两种通配符：*和？，前者代表多个字符，后者仅代表一个字符。至于student和goods信息如何映射成pojo对象，前面的文章中已经做过详细的介绍，这里就不做赘述了。

      96-104行配置了Writer的基本信息。Writer也是使用代理的方式，学生信息使用106-122行定义的studentWriter按照固定长的格式写入学生信息文件中，商品信息使用124-141行定义的goodsWriter按照CSV的格式写入商品信息文件中。MultiItemWriter的代码很简单，就不做详细解释了。如下：

package com.wanggc.springbatch.sample.multitypessinglefile;

import java.util.ArrayList;
import java.util.List;

import org.springframework.batch.item.ItemWriter;

import com.wanggc.springbatch.sample.multitypessinglefile.pojo.Goods;
import com.wanggc.springbatch.sample.multitypessinglefile.pojo.Student;

/**
 * 写处理类。
 * 
 * @author Wanggc
 * 
 * @param <T>
 */
@SuppressWarnings("unchecked")
public class MultiItemWriter<T> implements ItemWriter<T> {
    /** 写代理 */
    private List<ItemWriter<? super T>> delegates;

    public void setDelegates(List<ItemWriter<? super T>> delegates) {
        this.delegates = delegates;
    }

    @Override
    public void write(List<? extends T> items) throws Exception {
        // 学生信息的Writer
        ItemWriter studentWriter = (ItemWriter) delegates.get(0);
        // 商品信息的Writer
        ItemWriter goodsWriter = (ItemWriter) delegates.get(1);
        // 学生信息
        List<Student> studentList = new ArrayList<Student>();
        // 商品信息
        List<Goods> goodsList = new ArrayList<Goods>();
        // 将传过来的信息按照不同的类型添加到不同的List中
        for (int i = 0; i < items.size(); i++) {
            if ("Student".equals(items.get(i).getClass().getSimpleName())) {
                studentList.add((Student) items.get(i));
            } else {
                goodsList.add((Goods) items.get(i));
            }
        }
        // 如果学生List中有数据，就执行学生信息的写
        if (studentList.size() > 0) {
            studentWriter.write(studentList);
        }
        // 如果商品List中有数据，就执行商品信息的写
        if (goodsList.size() > 0) {
            goodsWriter.write(goodsList);
        }
    }
}

      至此，复合文件的读写操作已经讨论结束了。注意实例没有配置Processor。下面是一些辅助文件的信息。

      student和goods类的信息与前面文章一样，就不再贴出代码了。

      Job启动的代码如下：

package com.wanggc.springbatch.sample.multitypessinglefile;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.JobExecution;
import org.springframework.batch.core.JobParametersBuilder;
import org.springframework.batch.core.launch.JobLauncher;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Launch {
    public static void main(String[] args) {
        ApplicationContext context = new ClassPathXmlApplicationContext(
                "batch.xml");
        JobLauncher launcher = (JobLauncher) context.getBean("jobLauncher");
        Job job = (Job) context.getBean("multiTypeSingleFileJob");

        try {
            // JOB实行
            JobExecution result = launcher.run(
                    job,
                    new JobParametersBuilder()
                            .addString("inputFilePath",
                                    "C:\\testData\\multiTypesInput.txt")
                            .addString("outputFilePathStudent",
                                    "C:\\testData\\student.txt")
                            .addString("outputFilePathGoods",
                                    "C:\\testData\\goods.csv")
                            .toJobParameters());
            // 运行结果输出
            System.out.println(result.toString());
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

      Input文件内容如下图：

      处理结果的学生信息文件如下图：

     处理结果的商品信息文件如下图：

      Spring Batch对复合格式文件的读写操作就讨论到这里。至此，Spring Batch对文件简单操作的讨论也告一段落，下次将讨论Spring Batch读写DB的操作。