spring batch 建表 springbatch动态创建job

springbatch

job的创建使用

• job：作业，是批处理中的核心概念，是batch操作的基础单元，每个job由多个step组成
• step：步骤，任务完成的节点
• 每个job是由JobBuildFactory创建，每个step是由StepBuildFactory创建
• 示例：
  ``
  @Configuration
  @EnableBatchProcessing //开启批处理
  public class JobConfiguration {

/**
     * 创建任务对象的对象
     */
    @Autowired
    private JobBuilderFactory jobBuilderFactory;

    /**
     * 创建步骤对象的对象
     */
    @Autowired
    private StepBuilderFactory stepBuilderFactory;

    @Bean
    public Job helloJob(){

        return jobBuilderFactory.get("helloJob").start(helloStep1()).build();
    }

    @Bean
    public Step helloStep1(){

        return stepBuilderFactory.get("helloStep1").tasklet(new Tasklet() {
            @Override
            public RepeatStatus execute(StepContribution stepContribution, ChunkContext chunkContext) throws Exception {
                System.out.println("hello world");
                return RepeatStatus.FINISHED;
            }
        }).build();
    }
}

``

从数据库读取

• JdbcPagingItemReader

. 设置数据源
  . 设置查询条件
  . 将查询结果映射成实体类

• MySqlPagingQueryProvider // mysql分页查询支持器
• 代码示例：

JdbcPagingItemReader<User> jdbcPagingItemReader = new JdbcPagingItemReader<>();
    jdbcPagingItemReader.setDataSource(dataSource);
    jdbcPagingItemReader.setFetchSize(3);//每次从数据库拉取条数

    //设置查询条件
    MySqlPagingQueryProvider pagingQueryProvider = new MySqlPagingQueryProvider();
    pagingQueryProvider.setSelectClause("id,name,password");
    pagingQueryProvider.setFromClause("user");

    Map<String, Order> orderMap = new HashMap<>();
    orderMap.put("password",Order.DESCENDING);//设置排序字段
    pagingQueryProvider.setSortKeys(orderMap);
    jdbcPagingItemReader.setQueryProvider(pagingQueryProvider);

    //设置行映射器
    jdbcPagingItemReader.setRowMapper(new RowMapper<User>() {
        @Override
        public User mapRow(ResultSet resultSet, int i) throws SQLException {
            User user = new User();
            user.setId(resultSet.getInt(1));
            user.setName(resultSet.getString(2));
            user.setPassword(resultSet.getString(3));
            return user;
        }
    });
    return jdbcPagingItemReader;

从txt文件中获取数据

• FlatFileItemReader
• DelimitedLineTokenizer //行分词器
• DefaultLineMapper //行映射器，将一行数据映射成对应的实体
• defaultLineMapper.setLineTokenizer(delimitedLineTokenizer);
• flatFileItemReader.setLineMapper(defaultLineMapper);
• 代码示例：

```
    FlatFileItemReader<Hospital> flatFileItemReader = new FlatFileItemReader<>();
    flatFileItemReader.setEncoding("utf-8");
    flatFileItemReader.setLinesToSkip(1);//跳过第一行
    flatFileItemReader.setResource(new ClassPathResource("/data/hospital.txt"));

    //解析数据  按行分词
    DelimitedLineTokenizer delimitedLineTokenizer = new DelimitedLineTokenizer();
    delimitedLineTokenizer.setNames("id","org_name","org_type","addr","allow_no","cert_dept",
            "start_valid_date","end_invalid_date");

    //行映射器
    DefaultLineMapper<Hospital> defaultLineMapper = new DefaultLineMapper<>();
    defaultLineMapper.setLineTokenizer(delimitedLineTokenizer);
    defaultLineMapper.setFieldSetMapper(new FieldSetMapper<Hospital>() {
        @Override
        public Hospital mapFieldSet(FieldSet fieldSet) throws BindException {
            Hospital hospital = new Hospital();
            hospital.setId(fieldSet.readInt("id"));
            hospital.setAddr(fieldSet.readString("addr"));
            hospital.setAllowNo(fieldSet.readString("allow_no"));
            hospital.setCertDept(fieldSet.readString("cert_dept"));
            hospital.setEndValidDate(fieldSet.readString("end_invalid_date"));
            hospital.setOrgName(fieldSet.readString("org_name"));
            hospital.setOrgType(fieldSet.readString("org_type"));
            hospital.setStartValidDate(fieldSet.readString("start_valid_date"));
            return hospital;
        }
    });
    defaultLineMapper.afterPropertiesSet();
    flatFileItemReader.setLineMapper(defaultLineMapper);

    return flatFileItemReader;
```

从xml中读取数据

• StaxEventItemReader xml读取器
• pom引入jar包
  ``

<dependency>
      <groupId>com.thoughtworks.xstream</groupId>
      <artifactId>xstream</artifactId>
      <version>1.4.11.1</version>
  </dependency>

  <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-oxm</artifactId>
      <version>5.0.8.RELEASE</version>
  </dependency>

• xstream实现xml转对象
• spring-oxm遵循xstream接口规范，实现xml转对象
• 代码示例：
  ``

@Bean
      public ItemReader<User> xmlItemReader() {

          StaxEventItemReader<User> staxEventItemReader = new StaxEventItemReader<>();
          staxEventItemReader.setFragmentRootElementName("user");//设置根标签
          staxEventItemReader.setResource(new ClassPathResource("/data/user.xml"));//设置文件路径

          //将xml转成实体对象
          XStreamMarshaller xStreamMarshaller = new XStreamMarshaller();
          Map<String,Class> alias = new HashMap<>();
          alias.put("user",User.class);//key 为根标签，class是key标签下的所有标签映射到的对象
          xStreamMarshaller.setAliases(alias);

          staxEventItemReader.setUnmarshaller(xStreamMarshaller);

          return staxEventItemReader;
      }

``

多文件读取

• MultiResourceItemReader
• 多文件读取，其实就是一个一个文件读取
• MultiResourceItemReader需要设置文件读取代理，待读取文件资源
• 代码示例：
  ``
  @Value("classpath:/data/file*.txt")
  private Resource[] resources;
  @Bean
  public MultiResourceItemReader multiFileItemReader() {

MultiResourceItemReader<Hospital> multiResourceItemReader = new MultiResourceItemReader<>();
   //多文件读取，其实也是一个一个文件进行读取，需要设置文件读取器
   multiResourceItemReader.setDelegate(flatFileItemReader());
   multiResourceItemReader.setResources(resources);
   return multiResourceItemReader;

}

@Bean
public FlatFileItemReader flatFileItemReader(){
FlatFileItemReader flatFileItemReader = new FlatFileItemReader<>();
flatFileItemReader.setEncoding("utf-8");

DelimitedLineTokenizer delimitedLineTokenizer = new DelimitedLineTokenizer();
   delimitedLineTokenizer.setDelimiter(",");
   delimitedLineTokenizer.setNames("id","org_name","org_type","addr","allow_no","cert_dept",
           "start_valid_date","end_invalid_date");

   DefaultLineMapper<Hospital> defaultLineMapper = new DefaultLineMapper<>();
   defaultLineMapper.setLineTokenizer(delimitedLineTokenizer);
   defaultLineMapper.setFieldSetMapper(new FieldSetMapper<Hospital>() {
       @Override
       public Hospital mapFieldSet(FieldSet fieldSet) throws BindException {
           Hospital hospital = new Hospital();
           hospital.setStartValidDate(fieldSet.readString("start_valid_date"));
           hospital.setOrgType(fieldSet.readString("org_type"));
           hospital.setOrgName(fieldSet.readString("org_name"));
           hospital.setEndValidDate(fieldSet.readString("end_invalid_date"));
           hospital.setCertDept(fieldSet.readString("cert_dept"));
           hospital.setAllowNo(fieldSet.readString("allow_no"));
           hospital.setAddr(fieldSet.readString("addr"));
           hospital.setId(fieldSet.readInt("id"));
           return hospital;
       }
   });

   flatFileItemReader.setLineMapper(defaultLineMapper);

   return flatFileItemReader;

}
``

从文件中读取，并写入到数据库

• JdbcBatchItemWriter
• 代码示例：

@Bean
    public ItemWriter<Hospital> jdbcBatchItemWriter() {
        JdbcBatchItemWriter<Hospital> jdbcBatchItemWriter = new JdbcBatchItemWriter<>();
        jdbcBatchItemWriter.setDataSource(dataSource);
        jdbcBatchItemWriter.setSql(
                "INSERT INTO `hospital` (`id`, `org_name`, `org_type`, `addr`, `allow_no`, `cert_dept`, `start_valid_date`, `end_invalid_date`) " +
                        "VALUES (:id, :orgName, :orgType, :addr, :allowNo, :certDept, :startValidDate, :endValidDate)"
        );
        //将对象属性值映射到sql参数中
        jdbcBatchItemWriter.setItemSqlParameterSourceProvider(new BeanPropertyItemSqlParameterSourceProvider<>());
        return jdbcBatchItemWriter;
    }

从数据库读取，写入到普通文件

• FlatItemFileWriter
• 代码示例：

@Bean
    public ItemWriter<? super Hospital> flatFileItemWriter() {

        FlatFileItemWriter<Hospital> flatFileItemWriter = new FlatFileItemWriter<>();
        flatFileItemWriter.setEncoding("utf-8");
        //设置存放数据的文件路径
        flatFileItemWriter.setResource(new FileSystemResource("f:/hospital_generate.txt"));

        flatFileItemWriter.setLineAggregator(new LineAggregator<Hospital>() {
            ObjectMapper objectMapper = new ObjectMapper();
            @Override
            public String aggregate(Hospital item) {
                String result = null;
                try {
                    result = objectMapper.writeValueAsString(item);//将对象转json字符串
                } catch (JsonProcessingException e) {
                    e.printStackTrace();
                }

                return result;
            }
        });
        return flatFileItemWriter;

    }

从数据库读取并写入到xml文件

• StaxEventItemWriter
• XstreamMarshaller - xml标签元素与实体对象映射
• 代码示例

@Bean
    public ItemWriter<? super Hospital> xmlFileItemWriter() {
        StaxEventItemWriter<Hospital> staxEventItemWriter = new StaxEventItemWriter<>();
        staxEventItemWriter.setEncoding("utf-8");
        staxEventItemWriter.setResource(new FileSystemResource("f:/hospital.xml"));
        staxEventItemWriter.setRootTagName("hospitals");

        //XML标签与实体对象映射
        Map<String,Class<Hospital>> alias = new HashMap<>();
        alias.put("hospital",Hospital.class);

        XStreamMarshaller xStreamMarshaller = new XStreamMarshaller();
        xStreamMarshaller.setAliases(alias);

        staxEventItemWriter.setMarshaller(xStreamMarshaller);

        return staxEventItemWriter;

    }