Skip header, body and footer lines from file on Spring Batch

问题

I have this specifically file:

H;COD;CREATION_DATE;TOT_POR;TYPE
H;001;2013-10-30;20;R
D;DETAIL_VALUE;PROP_VALUE
D;003;3030
D;002;3031
D;005;3032
T;NUM_FOL;TOT
T;1;503.45

As you can see, it has header/body/footer lines. I'm looking for a ItemReader that skip these lines. I've done this ItemReader below who identify those lines, using PatternMatchingCompositeLineMapper.

<bean id="fileReader" class="org.springframework.batch.item.file.FlatFileItemReader">
        <property name="resource" ref="myFileReference" />
        <property name="lineMapper">
            <bean class="org.springframework.batch.item.file.mapping.PatternMatchingCompositeLineMapper">
                <property name="tokenizers">
                    <map>
                        <entry key="H*" value-ref="headerLineTokenizer"/>
                        <entry key="D*" value-ref="bodyLineTokenizer"/>
                        <entry key="T*" value-ref="footerLineTokenizer"/>
                    </map>
                </property>
                <property name="fieldSetMappers">
                    <map>
                        <entry key="H*" value-ref="headerMapper"/>
                        <entry key="D*" value-ref="bodyMapper"/>
                        <entry key="T*" value-ref="footerMapper"/>
                    </map>
                </property>
            </bean>
        </property>
    </bean>

I tried to add linesToSkip property equals 1, but it only skipped the header line. Is there a way to skip the first line of each block(header, body and footer)?

Thks.

回答1:

Nope. linesToSkip (as you wrote) just skip the first linesToSkip lines.
You have to write your own reader using multiorder-line example (or this post) as base and manage skip first line of each block manually

回答2:

Another option would be this one:

1- Create a Reader Factory

public class CustomFileReaderFactory implements BufferedReaderFactory {
@Override
public BufferedReader create(Resource resource, String encoding) throws IOException {
    return new CustomFileReader(new InputStreamReader(resource.getInputStream(), encoding));
}

2- Create your CustomFileReader (this will read one line and decide if we continue or we skip) and make sure to overwrite the readLine() method.

public class CustomFileReader extends BufferedReader {

public CustomFileReader(Reader in) {
    super(in);
}

@Override
public String readLine() throws IOException {
    String line = super.readLine();
    // your logic here
    if (hasToBeIgnored(line)) {
        return null;
    }
    return line;
}

3- Set your brand new Factory into your FlatFileItemReader:

yourFlatFileItemReader.setBufferedReaderFactory(new CustomFileReaderFactory());

来源：https://stackoverflow.com/questions/20956768/skip-header-body-and-footer-lines-from-file-on-spring-batch

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Spring

batch-processing

spring-batch