Spring-Batch学习总结（3）——如何数据输入
一．ItemReader概述
1.ItemReader:提供数据的接口
2.在这个接口中只有一个方法read(),它读取一个数据并且移动到下一个数据上去，在读取结束时必须返回一个null,否则表明数据没有读取完毕;
例：
OverViewApplication：

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package com.dhcc.batch.batchDemo.input.overview;

import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@EnableBatchProcessing
public class OverViewApplication {

    public static void main(String[] args) {
        SpringApplication.run(OverViewApplication.class, args);
    }
}

InputOverViewDemoJobConfiguration：

package com.dhcc.batch.batchDemo.input.overview;

import java.util.Arrays;
import java.util.List;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.item.ItemWriter;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class InputOverViewDemoJobConfiguration {
    @Autowired
    private JobBuilderFactory jobBuilderFactory;
    @Autowired
    private StepBuilderFactory stepBuilderFactory;

    @Bean
    public Job inputOverViewDemoJob() {
        return jobBuilderFactory.get("inputOverViewDemoJob").start(inputOverViewDemoJobStep()).build();

    }

    public Step inputOverViewDemoJobStep() {
        return stepBuilderFactory.get("inputOverViewDemoJobStep").chunk(2)
                .reader(inputOverViewDemoReader()).writer(outputOverViewDemoWriter()).build();
    }

    private ItemWriter outputOverViewDemoWriter() {
        return new ItemWriter() {

            @Override
            public void write(List items) throws Exception {
                for (String item : items) {
                    System.out.println("output writer data: " + item);
                }
            }
        };
    }

    @Bean
    public InputOverVierDemoItemReader inputOverViewDemoReader() {
        List data = Arrays.asList("dazhonghua", "xiaoriben", "meilijian", "falanxi", "deyizhi", "aierlan",
                "fandigang", "bajisitan", "baieluosi");
        return new InputOverVierDemoItemReader(data);
    }
}

InputOverVierDemoItemReader：

package com.dhcc.batch.batchDemo.input.overview;

import java.util.Iterator;
import java.util.List;

import org.springframework.batch.item.ItemReader;
import org.springframework.batch.item.NonTransientResourceException;
import org.springframework.batch.item.ParseException;
import org.springframework.batch.item.UnexpectedInputException;

public class InputOverVierDemoItemReader implements ItemReader {
    private final Iterator iterator;

    public InputOverVierDemoItemReader(List data) {
        this.iterator = data.iterator();
    }

    @Override
    public String read() throws Exception, UnexpectedInputException, ParseException, NonTransientResourceException {
        if (iterator.hasNext()) {
            return this.iterator.next();
        } else {
            return null;
        }
    }

}

运行结果：

二．从数据库中读取数据
1.在实际应用中，我们都需要从数据库中读取数据，并且进行分页读取，在spring-batch中为我们提供了JDBCPagingItemReader这个类进行数据库数据读取
2.例：再举这个例子之前我们在数据库中建立了个person_buf表，并向表中插入了100001条数据

接下来我们读取这个表中的数据为例，进行学习：
InputItemReaderJDBCApplication：

package com.dhcc.batch.batchDemo.input.db.jdbc;

import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@EnableBatchProcessing
public class InputItemReaderJDBCApplication {
    public static void main(String[] args) {
        SpringApplication.run(InputItemReaderJDBCApplication.class, args);

    }
}

InputDBJdbcItemReaderConfigruation：

package com.dhcc.batch.batchDemo.input.db.jdbc;

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.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepScope;
import org.springframework.batch.item.ItemWriter;
import org.springframework.batch.item.database.JdbcPagingItemReader;
import org.springframework.batch.item.database.Order;
import org.springframework.batch.item.database.support.MySQLPagingQueryProvider;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class InputDBJdbcItemReaderConfigruation {

    @Autowired
    private JobBuilderFactory jobBuilderFactory;

    @Autowired
    private StepBuilderFactory stepBuilderFactory;

    @Autowired
    @Qualifier("DBJdbcWriterDemo")
    private ItemWriter DBJbbcWriterDemo;

    @Autowired
    private DataSource dataSource;

    @Bean
    public Job DBJdbcItemReaderJob() {
        return jobBuilderFactory.get("DBJdbcItemReaderJob4")
                .start(DBJdbcItemReaderJobStep())
                .build();

    }

    @Bean
    public Step DBJdbcItemReaderJobStep() {
        return stepBuilderFactory.get("DBJdbcItemReaderJobStep4")
                .chunk(100)
                .reader(DBJbbcReaderDemo())
                .writer(DBJbbcWriterDemo)
                .build();
    }

    @Bean
    @StepScope
    public JdbcPagingItemReader DBJbbcReaderDemo() {
        JdbcPagingItemReader reader = new JdbcPagingItemReader<>();
        reader.setDataSource(this.dataSource); // 设置数据源
        reader.setFetchSize(100); // 设置一次最大读取条数
        reader.setRowMapper(new PersonRowMapper()); // 把数据库中的每条数据映射到Person对中
        MySqlPagingQueryProvider queryProvider = new MySqlPagingQueryProvider();
        queryProvider.setSelectClause("id,name,per_desc,create_time,update_time,sex,score,price"); // 设置查询的列
        queryProvider.setFromClause("from person_buf"); // 设置要查询的表
        Map sortKeys = new HashMap();// 定义一个集合用于存放排序列
        sortKeys.put("id", Order.ASCENDING);// 按照升序排序
        queryProvider.setSortKeys(sortKeys);
        reader.setQueryProvider(queryProvider);// 设置排序列
        return reader;
    }

}

DBJdbcWriterDemo：

package com.dhcc.batch.batchDemo.input.db.jdbc;

import java.util.List;

import org.springframework.batch.item.ItemWriter;
import org.springframework.stereotype.Component;
@Component("DBJdbcWriterDemo")
public class DBJdbcWriterDemo implements ItemWriter{

    @Override
    public void write(List items) throws Exception {
        for(Person person:items) {
            System.out.println(person);
        }
    }

}

Person

package com.dhcc.batch.batchDemo.input.db.jdbc;

import java.util.Date;

public class Person {
    private Integer id;
    private String name;
    private String perDesc;
    private Date createTime;
    private Date updateTime;
    private String sex;
    private Float score;
    private Double price;

    public Person() {
        super();
    }

    public Person(Integer id, String name, String perDesc, Date createTime, Date updateTime, String sex, Float score,
            Double price) {
        super();
        this.id = id;
        this.name = name;
        this.perDesc = perDesc;
        this.createTime = createTime;
        this.updateTime = updateTime;
        this.sex = sex;
        this.score = score;
        this.price = price;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public String getPerDesc() {
        return perDesc;
    }

    public void setPerDesc(String perDesc) {
        this.perDesc = perDesc;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }

    public Date getUpdateTime() {
        return updateTime;
    }

    public void setUpdateTime(Date updateTime) {
        this.updateTime = updateTime;
    }

    public String getSex() {
        return sex;
    }

    public void setSex(String sex) {
        this.sex = sex;
    }

    public Float getScore() {
        return score;
    }

    public void setScore(Float score) {
        this.score = score;
    }

    public Double getPrice() {
        return price;
    }

    public void setPrice(Double price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "Person [id=" + id + ", name=" + name + ", perDesc=" + perDesc + ", createTime=" + createTime + ", updateTime="
                + updateTime + ", sex=" + sex + ", score=" + score + ", price=" + price + "]";
    }

}

PersonRowMapper：

package com.dhcc.batch.batchDemo.input.db.jdbc;

import java.sql.ResultSet;
import java.sql.SQLException;

import org.springframework.jdbc.core.RowMapper;
/**
 * 实现将数据库中的每条数据映射到Person对象中
 * @author Administrator
 *
 */
public class PersonRowMapper implements RowMapper {

    /**
     * rs一条结果集，rowNum代表当前行
     */
    @Override
    public Person mapRow(ResultSet rs, int rowNum) throws SQLException {
        return new Person(rs.getInt("id")
                ,rs.getString("name")
                ,rs.getString("per_desc")
                ,rs.getDate("create_time")
                ,rs.getDate("update_time")
                ,rs.getString("sex")
                ,rs.getFloat("score")
                ,rs.getDouble("price"));
    }

}

运行结果：

1.FlatFileItemReader:
(1)set lines to skip:设置跳过前几行
(2)set resource:指定源文件地址
(3)设置一个行解析器映射行对应的结果集
2.例:我们在项目中的resources中放入了两个csv文件，我们以读取springbatchtest1.csv为例：
（1）观察文件存放路径：

（2）展示部分文件结构：

（3）编写代码：
AlipayTranDo ：

package com.dhcc.batch.batchDemo.input.flatFile;

public class AlipayTranDo {
        private String tranId;
        private String channel;
        private String tranType;
        private String counterparty;
        private String goods;
        private String amount;
        private String isDebitCredit;
        private String state;

        public AlipayTranDo(String tranId, String channel, String tranType, String counterparty, String goods,
                String amount, String isDebitCredit, String state) {
            super();
            this.tranId = tranId;
            this.channel = channel;
            this.tranType = tranType;
            this.counterparty = counterparty;
            this.goods = goods;
            this.amount = amount;
            this.isDebitCredit = isDebitCredit;
            this.state = state;
        }

        public String getTranId() {
            return tranId;
        }

        public void setTranId(String tranId) {
            this.tranId = tranId;
        }

        public String getChannel() {
            return channel;
        }

        public void setChannel(String channel) {
            this.channel = channel;
        }

        public String getTranType() {
            return tranType;
        }

        public void setTranType(String tranType) {
            this.tranType = tranType;
        }

        public String getCounterparty() {
            return counterparty;
        }

        public void setCounterparty(String counterparty) {
            this.counterparty = counterparty;
        }

        public String getGoods() {
            return goods;
        }

        public void setGoods(String goods) {
            this.goods = goods;
        }

        public String getAmount() {
            return amount;
        }

        public void setAmount(String amount) {
            this.amount = amount;
        }

        public String getIsDebitCredit() {
            return isDebitCredit;
        }

        public void setIsDebitCredit(String isDebitCredit) {
            this.isDebitCredit = isDebitCredit;
        }

        public String getState() {
            return state;
        }

        public void setState(String state) {
            this.state = state;
        }

        @Override
        public String toString() {
            return "AlipayTranDO{" +
                    "tranId='" + tranId + '\'' +
                    ", channel='" + channel + '\'' +
                    ", tranType='" + tranType + '\'' +
                    ", counterparty='" + counterparty + '\'' +
                    ", goods='" + goods + '\'' +
                    ", amount='" + amount + '\'' +
                    ", isDebitCredit='" + isDebitCredit + '\'' +
                    ", state='" + state + '\'' +
                    '}';
        }
    }

AlipayTranDoFileMapper：

package com.dhcc.batch.batchDemo.input.flatFile;

import org.springframework.batch.item.file.mapping.FieldSetMapper;
import org.springframework.batch.item.file.transform.FieldSet;
import org.springframework.validation.BindException;

public class AlipayTranDoFileMapper implements FieldSetMapper {

    @Override
    public AlipayTranDo mapFieldSet(FieldSet fieldSet) throws BindException {
        return new AlipayTranDo(fieldSet.readString("tranId")
                , fieldSet.readString("channel")
                ,fieldSet.readString("tranType")
                , fieldSet.readString("counterparty")
                , fieldSet.readString("goods")
                ,fieldSet.readString("amount")
                , fieldSet.readString("isDebitCredit")
                , fieldSet.readString("state")
                );
    }

}

FlatFileWriterDemo：

package com.dhcc.batch.batchDemo.input.flatFile;

import java.util.List;

import org.springframework.batch.item.ItemWriter;
import org.springframework.stereotype.Component;
@Component("FlatFileWriterDemo")
public class FlatFileWriterDemo implements ItemWriter{

    @Override
    public void write(List items) throws Exception {
        for(AlipayTranDo alipayTranDo:items) {
            System.out.println(alipayTranDo);
        }
    }

}

InputFaltFileItemReaderConfigruation：

package com.dhcc.batch.batchDemo.input.flatFile;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepScope;
import org.springframework.batch.item.ItemWriter;
import org.springframework.batch.item.file.FlatFileItemReader;
import org.springframework.batch.item.file.mapping.DefaultLineMapper;
import org.springframework.batch.item.file.transform.DelimitedLineTokenizer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;

@Configuration
public class InputFaltFileItemReaderConfigruation {

    @Autowired
    private JobBuilderFactory jobBuilderFactory;

    @Autowired
    private StepBuilderFactory stepBuilderFactory;

    @Autowired
    @Qualifier("FlatFileWriterDemo")
    private ItemWriter FlatFileWriterDemo;

    @Bean
    public Job FaltFileItemReaderJob() {
        return jobBuilderFactory.get("FaltFileItemReaderJob")
                .start(FaltFileItemReaderJobStep())
                .build();

    }

    @Bean
    public Step FaltFileItemReaderJobStep() {
        return stepBuilderFactory.get("FaltFileItemReaderJobStep")
                .chunk(100)
                .reader(FaltFileReaderDemo())
                .writer(FlatFileWriterDemo)
                .build();
    }

    @Bean
    @StepScope
    public FlatFileItemReader FaltFileReaderDemo() {
        FlatFileItemReader reader=new FlatFileItemReader();
        reader.setResource(new ClassPathResource("/data/init/springbatchtest1.csv"));
        reader.setLinesToSkip(5);

        DelimitedLineTokenizer tokenizer=new DelimitedLineTokenizer();
        tokenizer.setNames(new String[] 
                {"tranId","channel","tranType","counterparty","goods","amount","isDebitCredit","state"}
        );
        DefaultLineMapper lineMapper=new DefaultLineMapper();
        lineMapper.setLineTokenizer(tokenizer);
        lineMapper.setFieldSetMapper(new AlipayTranDoFileMapper());
        lineMapper.afterPropertiesSet();
        reader.setLineMapper(lineMapper);
        return reader;
    }

}

InputItemReaderFileApplication：

package com.dhcc.batch.batchDemo.input.flatFile;

import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@EnableBatchProcessing
public class InputItemReaderFileApplication {
    public static void main(String[] args) {
        SpringApplication.run(InputItemReaderFileApplication.class, args);

    }
}

运行结果：

四．使用ItemReader从xml文件中读取数据
1.使用StaxEventItemReader读取xml数据
2.例：在项目中加入一个weather.xml文件，以读取此文件为例
观察xml文件数据结构:

2018-10-08
d07|n02
小雨转阴
19/9℃
西南风


2018-10-09
d01|n00
多云转晴
21/7℃
东北风


2018-10-10
d00|n01
晴转多云
20/8℃
东北风3-4级转


2018-10-11
d01|n01
多云
18/9℃
东北风


2018-10-12
d00|n02
晴转阴
18/12℃
东北风


2018-10-13
d02|n02
阴
18/13℃
北风转南风


2018-10-14
d01|n02
多云转阴
17/11℃
东北风3-4级转


使用spring batch读取xml文件数据代码如下：
WeatherData:

package com.dhcc.batch.batchDemo.input.xmlFile;

public class WeatherData {
    private String date;
    private String icon;
    private String weather;
    private String temperature;
    private String winddirect;

    public WeatherData() {
        super();
    }

    public WeatherData(String date, String icon, String weather, String temperature, String winddirect) {
        super();
        this.date = date;
        this.icon = icon;
        this.weather = weather;
        this.temperature = temperature;
        this.winddirect = winddirect;
    }

    public String getDate() {
        return date;
    }

    public void setDate(String date) {
        this.date = date;
    }

    public String getIcon() {
        return icon;
    }

    public void setIcon(String icon) {
        this.icon = icon;
    }

    public String getWeather() {
        return weather;
    }

    public void setWeather(String weather) {
        this.weather = weather;
    }

    public String getTemperature() {
        return temperature;
    }

    public void setTemperature(String temperature) {
        this.temperature = temperature;
    }

    public String getWinddirect() {
        return winddirect;
    }

    public void setWinddirect(String winddirect) {
        this.winddirect = winddirect;
    }

    @Override
    public String toString() {
        return "WeatherData [date=" + date + ", icon=" + icon + ", weather=" + weather + ", temperature=" + temperature
                + ", winddirect=" + winddirect + "]";
    }

}

XMLFileDemoJobConfiguration :

package com.dhcc.batch.batchDemo.input.xmlFile;

import java.util.HashMap;
import java.util.Map;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepScope;
import org.springframework.batch.item.ItemWriter;
import org.springframework.batch.item.xml.StaxEventItemReader;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ClassPathResource;
import org.springframework.oxm.xstream.XStreamMarshaller;

@Configuration
public class XMLFileDemoJobConfiguration {
    @Autowired
    private JobBuilderFactory jobBuilderFactory;

    @Autowired
    private StepBuilderFactory stepBuilderFactory;

    @Autowired
    @Qualifier("XMLFileWriterDemo")
    private ItemWriter XMLFileWriterDemo;

    @Bean
    public Job XMLFileDemoReaderJobTwo() {
        return jobBuilderFactory.get("XMLFileDemoReaderJobTwo")
                .start(XMLFileDemoReaderStepTwo())
                .build();

    }

    @Bean
    public Step XMLFileDemoReaderStepTwo() {
        return stepBuilderFactory.get("XMLFileDemoReaderStepTwo")
                .chunk(2)
                .reader(XMLFileItemReader())
                .writer(XMLFileWriterDemo)
                .build();
    }

    @Bean
    @StepScope
    public StaxEventItemReader XMLFileItemReader() {
        StaxEventItemReader reader=new StaxEventItemReader();
        reader.setResource(new ClassPathResource("/xdata/init/weather.xml"));
        reader.setFragmentRootElementName("data");
        XStreamMarshaller unmarshaller=new XStreamMarshaller();
        Map map=new HashMap<>();
        map.put("data", WeatherData.class);
        unmarshaller.setAliases(map);
        reader.setUnmarshaller(unmarshaller);//序列化
        return reader;

    }

}

XMLFileWriterDemo :

package com.dhcc.batch.batchDemo.input.xmlFile;

import java.util.List;

import org.springframework.batch.item.ItemWriter;
import org.springframework.stereotype.Component;
@Component("XMLFileWriterDemo")
public class XMLFileWriterDemo implements ItemWriter{

    @Override
    public void write(List items) throws Exception {
        for(WeatherData weatherInfo:items) {
            System.out.println(weatherInfo);
        }
    }

}

XmlFileReaderApplication :

package com.dhcc.batch.batchDemo.input.xmlFile;

import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@EnableBatchProcessing
public class XmlFileReaderApplication {

    public static void main(String[] args) {
        SpringApplication.run(XmlFileReaderApplication.class, args);
    }
}

运行结果：

观察结果可得，我们成功的读取了xml文件
五．从多个文件读取数据
1.在一个给定的目录下一次读取多个文件时非常常见的
2.我们可以使用MultiResourceItemReader来注册一个input file并且设置代理的ItemReader去处理每一个源文件
例：我们在项目中同时存放两个csv文件，如下所示：

我们以读取这两个文件为例：
代码：
实体类与上面例子实体类一样AlipaytranDo,不做展示
AlipayTranDoMutipleMapper ：

package com.dhcc.batch.batchDemo.input.mutiple;

import org.springframework.batch.item.file.mapping.FieldSetMapper;
import org.springframework.batch.item.file.transform.FieldSet;
import org.springframework.validation.BindException;

public class AlipayTranDoMutipleMapper implements FieldSetMapper {

    @Override
    public AlipayTranDo mapFieldSet(FieldSet fieldSet) throws BindException {
        return new AlipayTranDo(fieldSet.readString("tranId")
                , fieldSet.readString("channel")
                ,fieldSet.readString("tranType")
                , fieldSet.readString("counterparty")
                , fieldSet.readString("goods")
                ,fieldSet.readString("amount")
                , fieldSet.readString("isDebitCredit")
                , fieldSet.readString("state")
                );
    }

}

MutipleFileDemoReaderApplication ：

package com.dhcc.batch.batchDemo.input.mutiple;

import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@EnableBatchProcessing
public class MutipleFileDemoReaderApplication {

    public static void main(String[] args) {
        SpringApplication.run(MutipleFileDemoReaderApplication.class, args);
    }
}

MutipleFileDemoReaderConfiguration ：

package com.dhcc.batch.batchDemo.input.mutiple;

import org.springframework.batch.core.Job;
import org.springframework.batch.core.Step;
import org.springframework.batch.core.configuration.annotation.JobBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepBuilderFactory;
import org.springframework.batch.core.configuration.annotation.StepScope;
import org.springframework.batch.item.ItemWriter;
import org.springframework.batch.item.file.FlatFileItemReader;
import org.springframework.batch.item.file.MultiResourceItemReader;
import org.springframework.batch.item.file.mapping.DefaultLineMapper;
import org.springframework.batch.item.file.transform.DelimitedLineTokenizer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.Resource;

@Configuration
public class MutipleFileDemoReaderConfiguration {
    @Autowired
    private JobBuilderFactory jobBuilderFactory;
    @Autowired
    private StepBuilderFactory stepBuilderFactory;

    @Autowired
    @Qualifier("MutipleFileItemWriterDemo")
    private ItemWriter MutipleFileItemWriterDemo;

    @Value("classpath*:/data/init/springbatchtest*.csv")
    private Resource[] resources;

    @Bean
    public Job MutipleFileDemoReaderJob3() {
        return jobBuilderFactory.get("MutipleFileDemoReaderJob3")
                .start(MutipleFileDemoItemReaderJobStep3())
                .build();

    }

    @Bean
    public Step MutipleFileDemoItemReaderJobStep3() {
        return stepBuilderFactory.get("MutipleFileDemoItemReaderJobStep3")
                .chunk(100)
                .reader(MutipleResourceItemReaderDemo())
                .writer(MutipleFileItemWriterDemo)
                .build();
    }

    @Bean
    @StepScope
    public MultiResourceItemReader MutipleResourceItemReaderDemo() {
        MultiResourceItemReader reader=new MultiResourceItemReader();
        reader.setDelegate(FaltFileReaderDemo());
        reader.setResources(resources);
        return reader;
    }

    @Bean
    @StepScope
    public FlatFileItemReader FaltFileReaderDemo() {
        FlatFileItemReader reader=new FlatFileItemReader();
//      reader.setResource(new ClassPathResource("alipayTranDo"));
        reader.setLinesToSkip(5);

        DelimitedLineTokenizer tokenizer=new DelimitedLineTokenizer();
        tokenizer.setNames(new String[] 
                {"tranId","channel","tranType","counterparty","goods","amount","isDebitCredit","state"}
        );
        DefaultLineMapper lineMapper=new DefaultLineMapper();
        lineMapper.setLineTokenizer(tokenizer);
        lineMapper.setFieldSetMapper(new AlipayTranDoMutipleMapper());
        lineMapper.afterPropertiesSet();
        reader.setLineMapper(lineMapper);
        return reader;
    }

}

MutipleFileItemWriterDemo :

package com.dhcc.batch.batchDemo.input.mutiple;

import java.util.List;

import org.springframework.batch.item.ItemWriter;
import org.springframework.stereotype.Component;
@Component("MutipleFileItemWriterDemo")
public class MutipleFileItemWriterDemo implements ItemWriter{

    @Override
    public void write(List items) throws Exception {
        for(AlipayTranDo alipayTranDo:items) {
            System.out.println(alipayTranDo);
        }
    }

}

六．ItemReader异常处理及重启
1.对于chunk类型的Step,spring batch为我们提供了用于管理它的状态
2.状态的管理是通过ItemStream接口来实现的
3.ItemStream接口：
（1）open():每一次step执行会调用
（2）Update():每一个chunk去执行都会调用
（3）Close():所有的chunk执行完毕会调用
4.图形：

此处不再展示例子

最后附上项目pom.xml

    4.0.0

    com.dhcc.batch
    batchDemo
    0.0.1-SNAPSHOT
    jar

    batchDemo
    Demo project for Spring Boot

    
        org.springframework.boot
        spring-boot-starter-parent
        2.0.4.RELEASE
         
    

    
        UTF-8
        UTF-8
        1.8
    

    
        
            org.springframework.boot
            spring-boot-starter-batch
        

        
            org.springframework.boot
            spring-boot-starter-test
            test
        

        
            org.springframework.batch
            spring-batch-test
            test
        

        
        
        
            org.springframework
            spring-oxm
            5.0.8.RELEASE
        

        
        
            com.thoughtworks.xstream
            xstream
            1.4.10
        

        

        
            org.springframework.boot
            spring-boot-starter-jdbc
        
        
            mysql
            mysql-connector-java
            runtime
        
    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

文章名称：Spring-batch（ItemReader）—数据读取从普通文件，数据库，XML，多文件数据读取
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