springbatch自学之路-11（初识ItemReader）

素颜马尾好姑娘i 2023-02-20 02:14 28阅读 0赞

**目录**

1.启动类

2.Job配置类

--------------------

1.启动类

package com.springbatch._09item_reader;
    
    import org.springframework.batch.core.configuration.annotation.EnableBatchProcessing;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    
    /**
     * SpringBatchDemo项目启动类
     *
     * @Package: PACKAGE_NAME
     * @ClassName: com.springbatch._01helloworld.SpringBatchConfig
     * @author: zq
     * @since: 2020/5/22 20:31
     * @version: 1.0
     * @Copyright: 2020 zq. All rights reserved.
     */
    @SpringBootApplication
    @EnableBatchProcessing
    public class SpringBatchConfig {
    
        public static void main(String[] args) {
    
            SpringApplication.run(SpringBatchConfig.class, args);
    
        }
    
    }

2.Job配置类

package com.springbatch._09item_reader;
    
    import org.springframework.batch.core.Job;
    import org.springframework.batch.core.JobParameter;
    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.beans.factory.annotation.Autowired;
    import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    
    import java.util.Arrays;
    import java.util.List;
    import java.util.Map;
    
    @Configuration
    public class ItemReaderJobConfig {
    
        //创建 创建job的对象
        @Autowired
        private JobBuilderFactory jobBuilderFactory;
    
        //创建 创建step的对象
        @Autowired
        private StepBuilderFactory stepBuilderFactory;
    
        Map<String, JobParameter> parameterMap;
    
        @Bean
        public Job itemReaderJob() {
    
            return jobBuilderFactory.get("itemReaderJob-01")
                    .start(itemReaderJobStep())
                    .build();
    
        }
    
        @Bean
        public Step itemReaderJobStep() {
            return stepBuilderFactory.get("itemReaderJobStep-01")
                    .<String, String>chunk(2)
                    .reader(myReaderDemo())
                    .writer(list -> {
    
                        System.out.println("write=================");
                        for (String item : list) {
    
                            System.out.println(item + "----");
    
                        }
    
                    })
                    .build();
        }
    
        @Bean
        public MyItemReader myReaderDemo() {
    
            List<String> list = Arrays.asList("1q", "az", "2w", "sx");
            return new MyItemReader(list);
    
        }
    
    }

reader

package com.springbatch._09item_reader;
    
    import org.springframework.batch.item.ItemReader;
    import org.springframework.batch.item.NonTransientResourceException;
    import org.springframework.batch.item.ParseException;
    import org.springframework.batch.item.UnexpectedInputException;
    
    import java.util.Iterator;
    import java.util.List;
    
    /**
     * @Package: com.springbatch._09item_reader
     * @ClassName: MyItemReader
     * @author: zq
     * @since: 2020/6/21 21:10
     * @version: 1.0
     * @Copyright: 2020 zq. All rights reserved.
     */
    public class MyItemReader implements ItemReader<String> {
    
        private final Iterator<String> iterater;
    
        public MyItemReader(List<String> list) {
    
            this.iterater = list.iterator();
    
        }
    
        @Override
        public String read() throws Exception, UnexpectedInputException, ParseException, NonTransientResourceException {
    
            if (iterater.hasNext()) {
    
                return iterater.next();
    
            } else {
                return null;
            }
        }
    }

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