Spring Batch：读取固定宽度文件而不换行

Question

我有一个固定长度的内容平面文件，其中包含如下示例记录，没有分隔符，因此它包含特殊的十六进制字符，并且数据也分布在多行中.但是每行都有 2000 个字节/字符，我需要继续从1-2000、2001-4000 等中挑选字节。我已经修复了索引字符。

注意 - 这里我不想读取 2000 行中的所有字符，只是想根据 Range 读取。

客户.java

@AllArgsConstructor
@NoArgsConstructor
@Builder
@Data
public class Customer {
    private String firstValue;
    private String secondValue;
    private String thirdValue;
    private String fourthValue;
}

错误

Java 豆

@Bean
public FlatFileItemReader<Customer> customerItemReader(){

    return new FlatFileItemReaderBuilder<Customer>()
            .name("customerItemReader")
            .linesToSkip(1)
            .resource(new ClassPathResource("/data/test.conv"))
            .fixedLength()
            .columns(new Range[] { new Range(3, 6), new Range(7, 13), new Range(14, 15), new Range(14, 15) })
            .names(new String[] { "firstValue", "secondValue", "thirdValue", "fourthValue" })
            .targetType(Customer.class)
            .build();
}

错误

org.springframework.batch.item.file.FlatFileParseException: Parsing error at line: 2 in resource=[class path resource [data/test.conv]], input=[560000000000411999999992052300000000D 0000        0000000000010000000100000040000000000000  00000000                    NYNNVX      N N 0      N004 000100000001000100000001000100000001000100000001000100000001000100000001000100000001                                                YNYNYYNNNNNYNNNN0004000000070000000300010000000000000000000000020000000000000000NN1N                         N00NNNND                                                                                                                                                       001NNN              00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000O840000000000000000000AN0201000000NNNC840                N  N00N A NN00400000000NNNNNUSAN       NNNN00000000000000NN141900INNNNNN   N                 N000000                 NN           200//0055//20000YNN MO    ¶200528000000       !!B3K555800000001A****00             00             00             00             00             00             00             00             00             00             00             00             00             00             00             00             0005230000000000000000                                                                                                                                                                 ]
    at org.springframework.batch.item.file.FlatFileItemReader.doRead(FlatFileItemReader.java:189) ~[spring-batch-infrastructure-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader.read(AbstractItemCountingItemStreamItemReader.java:93) ~[spring-batch-infrastructure-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.step.item.SimpleChunkProvider.doRead(SimpleChunkProvider.java:99) ~[spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.step.item.SimpleChunkProvider.read(SimpleChunkProvider.java:180) ~[spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.step.item.SimpleChunkProvider$1.doInIteration(SimpleChunkProvider.java:126) ~[spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.repeat.support.RepeatTemplate.getNextResult(RepeatTemplate.java:375) ~[spring-batch-infrastructure-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.repeat.support.RepeatTemplate.executeInternal(RepeatTemplate.java:215) ~[spring-batch-infrastructure-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.repeat.support.RepeatTemplate.iterate(RepeatTemplate.java:145) ~[spring-batch-infrastructure-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.step.item.SimpleChunkProvider.provide(SimpleChunkProvider.java:118) ~[spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.step.item.ChunkOrientedTasklet.execute(ChunkOrientedTasklet.java:71) ~[spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.step.tasklet.TaskletStep$ChunkTransactionCallback.doInTransaction(TaskletStep.java:407) ~[spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.step.tasklet.TaskletStep$ChunkTransactionCallback.doInTransaction(TaskletStep.java:331) ~[spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.transaction.support.TransactionTemplate.execute(TransactionTemplate.java:140) ~[spring-tx-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.batch.core.step.tasklet.TaskletStep$2.doInChunkContext(TaskletStep.java:273) ~[spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.scope.context.StepContextRepeatCallback.doInIteration(StepContextRepeatCallback.java:82) ~[spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.repeat.support.RepeatTemplate.getNextResult(RepeatTemplate.java:375) ~[spring-batch-infrastructure-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.repeat.support.RepeatTemplate.executeInternal(RepeatTemplate.java:215) ~[spring-batch-infrastructure-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.repeat.support.RepeatTemplate.iterate(RepeatTemplate.java:145) ~[spring-batch-infrastructure-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.step.tasklet.TaskletStep.doExecute(TaskletStep.java:258) ~[spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.step.AbstractStep.execute(AbstractStep.java:208) ~[spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.job.SimpleStepHandler.handleStep(SimpleStepHandler.java:148) [spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.job.AbstractJob.handleStep(AbstractJob.java:410) [spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.job.SimpleJob.doExecute(SimpleJob.java:136) [spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.job.AbstractJob.execute(AbstractJob.java:319) [spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.core.launch.support.SimpleJobLauncher$1.run(SimpleJobLauncher.java:147) [spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.core.task.SyncTaskExecutor.execute(SyncTaskExecutor.java:50) [spring-core-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.batch.core.launch.support.SimpleJobLauncher.run(SimpleJobLauncher.java:140) [spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_171]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_171]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_171]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_171]
    at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:344) [spring-aop-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:198) [spring-aop-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) [spring-aop-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.batch.core.configuration.annotation.SimpleBatchConfiguration$PassthruAdvice.invoke(SimpleBatchConfiguration.java:127) [spring-batch-core-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186) [spring-aop-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212) [spring-aop-5.2.6.RELEASE.jar:5.2.6.RELEASE]
    at com.sun.proxy.$Proxy57.run(Unknown Source) [na:na]
    at com.example.DatabaseOutputApplication.run(DatabaseOutputApplication.java:39) [classes/:na]
    at org.springframework.boot.SpringApplication.callRunner(SpringApplication.java:784) [spring-boot-2.2.7.RELEASE.jar:2.2.7.RELEASE]
    at org.springframework.boot.SpringApplication.callRunners(SpringApplication.java:768) [spring-boot-2.2.7.RELEASE.jar:2.2.7.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:322) [spring-boot-2.2.7.RELEASE.jar:2.2.7.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1226) [spring-boot-2.2.7.RELEASE.jar:2.2.7.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1215) [spring-boot-2.2.7.RELEASE.jar:2.2.7.RELEASE]
    at com.example.DatabaseOutputApplication.main(DatabaseOutputApplication.java:29) [classes/:na]
Caused by: org.springframework.batch.item.file.transform.IncorrectLineLengthException: Line is longer than max range 15
    at org.springframework.batch.item.file.transform.FixedLengthTokenizer.doTokenize(FixedLengthTokenizer.java:113) ~[spring-batch-infrastructure-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.item.file.transform.AbstractLineTokenizer.tokenize(AbstractLineTokenizer.java:130) ~[spring-batch-infrastructure-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.item.file.mapping.DefaultLineMapper.mapLine(DefaultLineMapper.java:43) ~[spring-batch-infrastructure-4.2.2.RELEASE.jar:4.2.2.RELEASE]
    at org.springframework.batch.item.file.FlatFileItemReader.doRead(FlatFileItemReader.java:185) ~[spring-batch-infrastructure-4.2.2.RELEASE.jar:4.2.2.RELEASE]

我也试过了

 @Bean
public FlatFileItemReader<Customer> customerItemReader(){
    FixedLengthTokenizer tokenizer = new FixedLengthTokenizer();
    tokenizer.setNames("firstValue", "secondValue", "thirdValue", "fourthValue", "fifthValue", "sixthValue", "seventhValue", "eighthValue", "ninethValue", "dummyRange");
    tokenizer.setColumns(
            new Range(3, 6), new Range(7, 13), new Range(14,15), new Range(16,24), new Range(25, 28), new Range(29,32), new Range(33, 36), new Range(1322, 1324),
            new Range(1406, 1408), new Range(1409));

    DefaultLineMapper<Customer> customerLineMapper = new DefaultLineMapper<>();
    customerLineMapper.setLineTokenizer(tokenizer);
    customerLineMapper.setFieldSetMapper(new CustomerFieldSetMapper());
    customerLineMapper.afterPropertiesSet();

    FlatFileItemReader<Customer> reader = new FlatFileItemReader<>();
    reader.setLinesToSkip(1);
    reader.setResource(new ClassPathResource("/data/test.conv"));
    reader.setLineMapper(customerLineMapper);
    reader.setStrict(false);
    return reader;
}

当您没有分隔符并且您的数据分布在多行时，这些解决方案不起作用。这里 1406 column 索引存在于不同的行中，并且分隔符已由大型机在文件中生成。请在此处指导。

Answer 1

这里的主要问题是FlatFileItemReader 假设您有换行符，而您没有。对我来说最清晰的解决方案是复制/粘贴该类并将readLine() 方法换成具有适当数量字符的方法。不幸的是，由于大部分类是私有的，你不能轻易地扩展和覆盖。

package org.springframework.batch.item.file;

import java.io.BufferedReader;
import java.io.IOException;
import java.nio.charset.Charset;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.batch.item.ReaderNotOpenException;
import org.springframework.batch.item.file.separator.RecordSeparatorPolicy;
import org.springframework.batch.item.file.separator.SimpleRecordSeparatorPolicy;
import org.springframework.batch.item.support.AbstractItemCountingItemStreamItemReader;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.core.io.Resource;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.util.StringUtils;

/**
 * Modified version of {@link FlatFileItemWriter} which reads in mainframe style files with fixed width and no line breaks.
 * Still a restartable {@link ItemReader} that reads lines from input {@link #setResource(Resource)}. Line is defined by the
 * {@link #setRecordSeparatorPolicy(RecordSeparatorPolicy)} and mapped to item using {@link #setLineMapper(LineMapper)}.
 * If an exception is thrown during line mapping it is rethrown as {@link FlatFileParseException} adding information
 * about the problematic line and its line number.
 *
 * @author Robert Kasanicky
 * @author Dean Clark
 */
public class FixedLengthFlatFileItemReader<T> extends AbstractItemCountingItemStreamItemReader<T> implements ResourceAwareItemReaderItemStream<T>, InitializingBean {

    private static final Log logger = LogFactory.getLog(FlatFileItemReader.class);

    // default encoding for input files
    public static final String DEFAULT_CHARSET = Charset.defaultCharset().name();

    private RecordSeparatorPolicy recordSeparatorPolicy = new SimpleRecordSeparatorPolicy();

    private Resource resource;

    private BufferedReader reader;

    private int lineCount = 0;

    private String[] comments = new String[] { "#" };

    private boolean noInput = false;

    private String encoding = DEFAULT_CHARSET;

    private LineMapper<T> lineMapper;

    private int linesToSkip = 0;

    private LineCallbackHandler skippedLinesCallback;

    private boolean strict = true;

    private BufferedReaderFactory bufferedReaderFactory = new DefaultBufferedReaderFactory();

    // CHANGE: Added a variable to store Line Length
    private Integer lineLength;
    
    public FixedLengthFlatFileItemReader() {
        setName(ClassUtils.getShortName(FlatFileItemReader.class));
    }

    /**
    * In strict mode the reader will throw an exception on
    * {@link #open(org.springframework.batch.item.ExecutionContext)} if the input resource does not exist.
    * @param strict <code>true</code> by default
    */
    public void setStrict(final boolean strict) {
        this.strict = strict;
    }

    /**
    * @param skippedLinesCallback will be called for each one of the initial skipped lines before any items are read.
    */
    public void setSkippedLinesCallback(final LineCallbackHandler skippedLinesCallback) {
        this.skippedLinesCallback = skippedLinesCallback;
    }

    /**
    * Public setter for the number of lines to skip at the start of a file. Can be used if the file contains a header
    * without useful (column name) information, and without a comment delimiter at the beginning of the lines.
    *
    * @param linesToSkip the number of lines to skip
    */
    public void setLinesToSkip(final int linesToSkip) {
        this.linesToSkip = linesToSkip;
    }

    /**
    * Setter for line mapper. This property is required to be set.
    * @param lineMapper maps line to item
    */
    public void setLineMapper(final LineMapper<T> lineMapper) {
        this.lineMapper = lineMapper;
    }

    /**
    * Setter for the encoding for this input source. Default value is {@link #DEFAULT_CHARSET}.
    *
    * @param encoding a properties object which possibly contains the encoding for this input file;
    */
    public void setEncoding(final String encoding) {
        this.encoding = encoding;
    }

    /**
    * Factory for the {@link BufferedReader} that will be used to extract lines from the file. The default is fine for
    * plain text files, but this is a useful strategy for binary files where the standard BufferedReaader from java.io
    * is limiting.
    *
    * @param bufferedReaderFactory the bufferedReaderFactory to set
    */
    public void setBufferedReaderFactory(final BufferedReaderFactory bufferedReaderFactory) {
        this.bufferedReaderFactory = bufferedReaderFactory;
    }

    /**
    * Setter for comment prefixes. Can be used to ignore header lines as well by using e.g. the first couple of column
    * names as a prefix.
    *
    * @param comments an array of comment line prefixes.
    */
    public void setComments(final String[] comments) {
        this.comments = new String[comments.length];
        System.arraycopy(comments, 0, this.comments, 0, comments.length);
    }

    /**
    * Public setter for the input resource.
    */
    @Override
    public void setResource(final Resource resource) {
        this.resource = resource;
    }

    /**
    * Public setter for the recordSeparatorPolicy. Used to determine where the line endings are and do things like
    * continue over a line ending if inside a quoted string.
    *
    * @param recordSeparatorPolicy the recordSeparatorPolicy to set
    */
    public void setRecordSeparatorPolicy(final RecordSeparatorPolicy recordSeparatorPolicy) {
        this.recordSeparatorPolicy = recordSeparatorPolicy;
    }

    /**
    * @return string corresponding to logical record according to
    * {@link #setRecordSeparatorPolicy(RecordSeparatorPolicy)} (might span multiple lines in file).
    */
    @Override
    protected T doRead() throws Exception {
        if (noInput) {
            return null;
        }

        final String line = readLine();

        if (line == null) {
            return null;
        } else {
            try {
                return lineMapper.mapLine(line, lineCount);
            } catch (final Exception ex) {
                throw new FlatFileParseException("Parsing error at line: " + lineCount + " in resource=["
                        + resource.getDescription() + "], input=[" + line + "]", ex, line, lineCount);
            }
        }
    }

    /**
    * @return next line (skip comments).getCurrentResource
    */
    // CHANGE: Modified readLine() to pull in a set number of characters
    private String readLine() {

        if (reader == null) {
            throw new ReaderNotOpenException("Reader must be open before it can be read.");
        }

        String line = null;

        try {
            
            // CHANGE: READ IN LINE BASED ON LINE LENGTH
            final char[] chars = new char[lineLength + 1];
            
            final int charsRead = reader.read(chars, 0, lineLength);
            if (charsRead <= 10) {
                noInput = true;
                return null;
            }
            line = new String(chars);
            // END CHANGE: READ IN LINE BASED ON LINE LENGTH
            
            lineCount++;
            while (isComment(line)) {
                line = reader.readLine();
                if (line == null) {
                    return null;
                }
                lineCount++;
            }

            line = applyRecordSeparatorPolicy(line);
        } catch (final IOException e) {
            // Prevent IOException from recurring indefinitely
            // if client keeps catching and re-calling
            noInput = true;
            throw new NonTransientFlatFileException("Unable to read from resource: [" + resource + "]", e, line,
                    lineCount);
        }
        return line;
    }

    private boolean isComment(final String line) {
        for (final String prefix : comments) {
            if (line.startsWith(prefix)) {
                return true;
            }
        }
        return false;
    }

    @Override
    protected void doClose() throws Exception {
        lineCount = 0;
        if (reader != null) {
            reader.close();
        }
    }

    @Override
    protected void doOpen() throws Exception {
        Assert.notNull(resource, "Input resource must be set");
        Assert.notNull(recordSeparatorPolicy, "RecordSeparatorPolicy must be set");

        noInput = true;
        if (!resource.exists()) {
            if (strict) {
                throw new IllegalStateException("Input resource must exist (reader is in 'strict' mode): " + resource);
            }
            logger.warn("Input resource does not exist " + resource.getDescription());
            return;
        }

        if (!resource.isReadable()) {
            if (strict) {
                throw new IllegalStateException("Input resource must be readable (reader is in 'strict' mode): "
                        + resource);
            }
            logger.warn("Input resource is not readable " + resource.getDescription());
            return;
        }

        reader = bufferedReaderFactory.create(resource, encoding);
        for (int i = 0; i < linesToSkip; i++) {
            final String line = readLine();
            if (skippedLinesCallback != null) {
                skippedLinesCallback.handleLine(line);
            }
        }
        noInput = false;
    }

    @Override
    public void afterPropertiesSet() throws Exception {
        Assert.notNull(lineMapper, "LineMapper is required");
        // CHANGE: Added an assertion to verify Line Length was provided
        Assert.notNull(lineLength, "Line length is required");
    }

    @Override
    protected void jumpToItem(final int itemIndex) throws Exception {
        for (int i = 0; i < itemIndex; i++) {
            readLine();
        }
    }

    private String applyRecordSeparatorPolicy(String line) throws IOException {

        String record = line;
        while ((line != null) && !recordSeparatorPolicy.isEndOfRecord(record)) {
            line = this.reader.readLine();
            if (line == null) {
                if (StringUtils.hasText(record)) {
                    // A record was partially complete since it hasn't ended but
                    // the line is null
                    throw new FlatFileParseException("Unexpected end of file before record complete", record, lineCount);
                } else {
                    // Record has no text but it might still be post processed
                    // to something (skipping preProcess since that was already
                    // done)
                    break;
                }
            } else {
                lineCount++;
            }
            record = recordSeparatorPolicy.preProcess(record) + line;
        }

        return recordSeparatorPolicy.postProcess(record);

    }

    // CHANGE: Added a setter for Line Length
    public void setLineLength(final Integer lineLength) {
        this.lineLength = lineLength;
    }
    
}

Answer 2

您可以使用 isStrict 标志来阅读此问题 - 单独使用标记器，您的​​问题将得到解决

我已经实现了-fixedLengthTokenizer 如下

  @Value("classpath:mainframe.txt")
    private Resource resource;



 @Bean
    public FlatFileItemReader fixLengthItemReader(){
        FlatFileItemReader reader = new FlatFileItemReader();
        reader.setResource(resource);
        reader.setLineMapper(new DefaultLineMapper() {
            {
                setLineTokenizer(fixedLengthTokenizer());
                setFieldSetMapper(new BeanWrapperFieldSetMapper<Customer>() {
                    {
                        setTargetType(Customer.class);
                    }
                });
            }
        });
        return reader;
    }



@Bean
public FixedLengthTokenizer fixedLengthTokenizer() {
    FixedLengthTokenizer tokenizer = new FixedLengthTokenizer();
    tokenizer.setColumns(new Range[] { new Range(3, 6), new Range(7, 13), new Range(14, 15), new Range(14, 15) });
    tokenizer.setNames(new String[] { "firstValue", "secondValue", "thirdValue", "fourthValue" });
    tokenizer.setStrict(false);
    return tokenizer;
}

注意 - 记得设置这个标志 --> tokenizer.setStrict(false);