评论需要 reader.markSupported() 到 return true beanio

Question

Xml 文件

<beanio xmlns="http://www.beanio.org/2012/03"
            xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
            xsi:schemaLocation="http://www.beanio.org/2012/03 http://www.beanio.org/2012/03/mapping.xsd">

        <stream name="stream" format="delimited" ignoreUnidentifiedRecords="true">
            <parser>
                <property name="delimiter" value="|"/>
                <property name="comments" value="Response Codes:,|File Trailer|,File Header|"/>
            </parser>

            <group name="HeaderRecord">
                <record>
                .
                .
                .
                </record>
            </group>
            <group name="GroupHeader">
                <record>
                .
                .
                .
                .
                </record>
            </group>
        </stream>
</beanio>

包含记录的文件如下所示

1   File Header|
.   HeaderRecord text.....
.   GroupHeader text......
19  Response Codes:
20                 |A - Whosebug           |                
21                 |B - Facebook                |               
22                 |C - Google                  |                
23  |File Trailer|



Error 
java.lang.IllegalArgumentException: Comments require reader.markSupported() to return true
    at org.beanio.stream.util.CommentReader.<init>(CommentReader.java:61)
    at org.beanio.stream.delimited.DelimitedReader.<init>(DelimitedReader.java:149)
    at org.beanio.stream.delimited.DelimitedRecordParserFactory.createReader(DelimitedRecordParserFactory.java:56)
    at org.beanio.internal.parser.StreamFormatSupport.createRecordReader(StreamFormatSupport.java:61)
    at org.beanio.internal.parser.Stream.createBeanReader(Stream.java:88)

我想忽略文件头、尾部和响应代码。响应代码从下一行开始。建议在属性中发表评论的各种博客。谁能解释为什么它不起作用？

Answer 1

问题出在您用来从中读取数据的 Reader 实现，如错误消息所示：

java.lang.IllegalArgumentException: Comments require reader.markSupported() to return true

您需要使用支持缓冲的 Reader，即实现 mark() 和 reset() 方法的 Reader。请参阅文档的 section 4.1.2 以及 comments 属性名称的描述和解释，其中指出：

A comma separated list of values for identifying commented lines. If a line read from an input stream begins with any of the configured values, the line is ignored. A backslash may be used to escape a comma and itself. All whitespace is preserved.

Enabling comments require the input reader passed to StreamFactory to support marking. Among others, Java's BufferedReader and StringReader support marking.

要使注释生效，您需要使用 BufferedReader 或 StringReader

读取数据

InputStream inputStream = ... // obtain some input stream to the source of your data 
Reader reader = new BufferedReader(new InputStreamReader(inputStream));
BeanReader beanReader = factory.createReader("streamName", reader);

评论需要 reader.markSupported() 到 return true beanio

Comments require reader.markSupported() to return true beanio

java

bean-io