Spring 批处理 : Reading a File : if field is empty setting the default value

Question

I am very new to spring batch. I have requirement in which i have to read a file having a header(Field Names) record and data records

1. i have to validate 1st record (check the field names matching against set of predefined names)- note that this record need to be skipped- i mean should not be part of items in processor)

2. read and store rest of the field values to a POJO

3. if the field 'date' is empty , i need to set the default value as 'xxxx-yy-zz'

i am unable to 1st and 3rd requirement with batchhere is the sample reader XML. please help

 <bean id="reader" class="org.springframework.batch.item.file.FlatFileItemReader">
     <property name="resource" value="classpath:input/import" /> 
     <property name="encoding" value="UTF-8" />
    <property name="linesToSkip" value="1" />
    <property name="lineMapper" ref="line.mapper"/>
 </bean>

 <bean id="line.mapper" class="org.springframework.batch.item.file.mapping .DefaultLineMapper">
    <property name="lineTokenizer" ref="line.tokenizer"/>
    <property name="fieldSetMapper" ref="fieldSet.enity.mapper"/>
 </bean>

 <bean id="line.tokenizer" class="org.springframework.batch.item.file.transfo  rm.DelimitedLineTokenizer">
     <property name="delimiter">
       <util:constant static-field="org.springframework.batch.item.file.transfo rm.DelimitedLineTokenizer.DELIMITER_TAB"/>
     </property>
     <property name="names" value="id,date,age " />
     <property name="strict" value="false"/>
</bean>

  <bean id="fieldSet.enity.mapper" class="org.springframework.batch.item.file.mapping .BeanWrapperFieldSetMapper">
      <property name="targetType" value="a.b.myPOJO"/>
      <property name="customEditors">
           <map>
              <entry key="java.util.Date">
                     <bean class="org.springframework.beans.propertyeditors.C ustomDateEditor">
                           <constructor-arg>
                                <bean class="java.text.SimpleDateFormat">
                                         <constructor-arg value="yyyy-mm-dd" />
                                 </bean>
                           </constructor-arg>
                           <constructor-arg value="true" />
                     </bean>
               </entry>
          </map>
     </property>

Answer 1

创建您自己的自定义 FieldSetMapper，如下所示

CustomeFieldSetMapper implements FieldSetMapper<a.b.myPOJO> {

@Override
public a.b.myPOJO mapFieldSet(FieldSet fs) {
           a.b.myPOJO  myPOJO = new a.b.myPOJO();
           if(fs.readString("date").isEmpty()){
               myPOJO.setDate("xxxx-yy-zz");
           }
           return a.b.myPOJO;
    } 
}