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：
1 <?xml version="1.0" encoding="UTF-8"?> 2 <bean:beans xmlns="http://www.springframework.org/schema/batch" 3 xmlns:bean="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xmlns:p="http://www.springframework.org/schema/p" xmlns:tx="http://www.springframework.org/schema/tx" 5 xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" 6 xmlns:util="http://www.springframework.org/schema/util" 7 xsi:schemaLocation="http://www.springframework.org/schema/beans 8 http://www.springframework.org/schema/beans/spring-beans-3.0.xsd 9 http://www.springframework.org/schema/tx 10 http://www.springframework.org/schema/tx/spring-tx-3.0.xsd 11 http://www.springframework.org/schema/aop 12 http://www.springframework.org/schema/aop/spring-aop-3.0.xsd 13 http://www.springframework.org/schema/context 14 http://www.springframework.org/schema/context/spring-context-2.5.xsd 15 http://www.springframework.org/schema/batch 16 http://www.springframework.org/schema/batch/spring-batch-2.1.xsd 17 http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd"> 18 19 <bean:import resource="applicationContext.xml" /> 20 <!-- Job的配置信息 --> 21 <job id="multiTypeSingleFileJob"> 22 <step id="xmlFileReadAndWriterStep"> 23 <tasklet> 24 <chunk reader="multiTypesItemReader" writer="multiTypesItemWriter" 25 commit-interval="1"> 26 <streams> 27 <stream ref="studentWriter" /> 28 <stream ref="goodsWriter" /> 29 </streams> 30 </chunk> 31 </tasklet> 32 </step> 33 </job> 34 35 <!-- 不同格式数据的文件读取 --> 36 <bean:bean id="multiTypesItemReader" 37 class="org.springframework.batch.item.file.FlatFileItemReader" scope="step"> 38 <bean:property name="resource" 39 value="file:#{jobParameters['inputFilePath']}" /> 40 <bean:property name="lineMapper"> 41 <bean:bean 42 class="org.springframework.batch.item.file.mapping.PatternMatchingCompositeLineMapper"> 43 <bean:property name="tokenizers"> 44 <bean:map> 45 <bean:entry key="student*" value-ref="studentTokenizer" /> 46 <bean:entry key="goods*" value-ref="goodsTokenizer" /> 47 </bean:map> 48 </bean:property> 49 <bean:property name="fieldSetMappers"> 50 <bean:map> 51 <bean:entry key="student*" value-ref="studentFieldSetMapper" /> 52 <bean:entry key="goods*" value-ref="goodsFieldSetMapper" /> 53 </bean:map> 54 </bean:property> 55 </bean:bean> 56 </bean:property> 57 </bean:bean> 58 <bean:bean id="studentTokenizer" 59 class="org.springframework.batch.item.file.transform.DelimitedLineTokenizer"> 60 <bean:property name="delimiter" value="," /> 61 <bean:property name="names"> 62 <bean:list> 63 <bean:value>student</bean:value> 64 <bean:value>ID</bean:value> 65 <bean:value>name</bean:value> 66 <bean:value>age</bean:value> 67 <bean:value>score</bean:value> 68 </bean:list> 69 </bean:property> 70 </bean:bean> 71 <bean:bean id="studentFieldSetMapper" 72 class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"> 73 <bean:property name="prototypeBeanName" value="student" /> 74 <bean:property name="distanceLimit" value="100" /> 75 </bean:bean> 76 <!-- 学生Pojo类 --> 77 <bean:bean id="student" 78 class="com.wanggc.springbatch.sample.multitypessinglefile.pojo.Student" 79 scope="prototype" /> 80 81 <bean:bean id="goodsTokenizer" 82 class="org.springframework.batch.item.file.transform.FixedLengthTokenizer"> 83 <bean:property name="columns" value="6-13,14-17,18-22,23-32,33-" /> 84 <bean:property name="names" 85 value="isin,quantity,price,customer,buyDay" /> 86 </bean:bean> 87 <bean:bean id="goodsFieldSetMapper" 88 class="org.springframework.batch.item.file.mapping.BeanWrapperFieldSetMapper"> 89 <bean:property name="prototypeBeanName" value="goods" /> 90 </bean:bean> 91 <!-- 商品Pojo类 --> 92 <bean:bean id="goods" 93 class="com.wanggc.springbatch.sample.multitypessinglefile.pojo.Goods" 94 scope="prototype" /> 95 96 <bean:bean id="multiTypesItemWriter" 97 class="com.wanggc.springbatch.sample.multitypessinglefile.MultiItemWriter"> 98 <bean:property name="delegates"> 99 <bean:list> 100 <bean:ref bean="studentWriter" /> 101 <bean:ref bean="goodsWriter" /> 102 </bean:list> 103 </bean:property> 104 </bean:bean> 105 <!-- 学生信息的写 --> 106 <bean:bean id="studentWriter" 107 class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step"> 108 <bean:property name="resource" 109 value="file:#{jobParameters['outputFilePathStudent']}" /> 110 <bean:property name="lineAggregator"> 111 <bean:bean 112 class="org.springframework.batch.item.file.transform.FormatterLineAggregator"> 113 <bean:property name="fieldExtractor"> 114 <bean:bean 115 class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor"> 116 <bean:property name="names" value="ID,name,age,score" /> 117 </bean:bean> 118 </bean:property> 119 <bean:property name="format" value="%-9s%-9s%3d%-2.0f" /> 120 </bean:bean> 121 </bean:property> 122 </bean:bean> 123 <!-- 商品信息的写 --> 124 <bean:bean id="goodsWriter" 125 class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step"> 126 <bean:property name="resource" 127 value="file:#{jobParameters['outputFilePathGoods']}" /> 128 <bean:property name="lineAggregator"> 129 <bean:bean 130 class="org.springframework.batch.item.file.transform.DelimitedLineAggregator"> 131 <bean:property name="fieldExtractor"> 132 <bean:bean 133 class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor"> 134 <bean:property name="names" 135 value="isin,quantity,price,customer,buyDay" /> 136 </bean:bean> 137 </bean:property> 138 </bean:bean> 139 </bean:property> 140 </bean:bean> 141 </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。
