如何在Spring Batch中读取复杂的JSON? [英] How to read a complex JSON in spring batch?

问题描述

我下面有一个复杂的JSON.我正在使用FlatFileItemReader读取它.如何使用自定义的ComplexJsonRecordSeparatorPolicy忽略最后一行]"?

[
  {"firstName":"Tom", "lastName":"Cruise"}, 
  {"firstName":"Bruce", "lastName":"Willis"},
  {"firstName":"Liam", "lastName":"Neeson"}
]

我的ComplexJsonRecordSeparatorPolicy如下所示.当我在第4行中有]"时，该类成功工作，但是，在第5行中仅向该行提供]"时，它将引发错误，因为我的后处理器会删除该行而不是忽略它. /p>

public class ComplexJsonRecordSeparatorPolicy extends JsonRecordSeparatorPolicy {

    @Override
    public boolean isEndOfRecord(String line) {

        return StringUtils.countOccurrencesOf(line, "{") == StringUtils.countOccurrencesOf(line, "}")
                && (line.trim().endsWith("}") || line.trim().endsWith(",") || line.trim().endsWith("]"));
    }

    @Override
    public String postProcess(String record) {
        if (record.startsWith("["))
            record = record.substring(1);
        if ((record.endsWith("]") || record.endsWith(",")))
            record = record.substring(0, record.length() - 1);
        return super.postProcess(record);
    }
}

解决方案

我为此创建了一个小示例.请看看，让我知道您的想法

https://github.com/bigzidane/spring-batch-jsonListItem-reader .

有关更多信息，我创建了一个Reader，它将JSON解析为一个列表，然后通过'classToBound'将每个条目映射到POJO，然后由每个遵循Spring Batch标准返回.

该示例将Json文件作为

[
    {
        "name": "zidane",
        "nation": "france"
    },
    {
        "name": "ronaldo",
        "nation": "brazil"
    },
    {
        "name": "marcelo",
        "nation": "brazil"
    }
]

作业配置

<job id="exampleJsonReaderJob" xmlns="http://www.springframework.org/schema/batch">
        <step id="stepId">
            <tasklet>
                <chunk reader="exampleJsonReader" writer="exampleWriter" processor="exampleProcessor" commit-interval="5" />
            </tasklet>
        </step>
    </job>

读者

<bean id="exampleJsonReader" class="com.itservicesdepot.example.springbatch.jsonreader.reader.JsonFileListItemReader" scope="step">
        <property name="resource" value="classpath:soccers.json" />
        <property name="classToBound" value="com.itservicesdepot.example.springbatch.jsonreader.model.SoccerJsonEntry" />
    </bean>

处理器和写入器只是普通的.

在阅读器中，有一个属性"classToBound"，即Pojo，它是在Json列表中具有项目的顶部地图.

I have a complex JSON below. I am reading it using FlatFileItemReader. How can I ignore the last line "]", with my customized ComplexJsonRecordSeparatorPolicy?

[
  {"firstName":"Tom", "lastName":"Cruise"}, 
  {"firstName":"Bruce", "lastName":"Willis"},
  {"firstName":"Liam", "lastName":"Neeson"}
]

My ComplexJsonRecordSeparatorPolicy looks like below. This class is successfully working, when I have "]" in line no 4 but, it throws an error when the line is supplied with only "]" in line no 5, as my post processor deletes the line instead of ignoring it.

public class ComplexJsonRecordSeparatorPolicy extends JsonRecordSeparatorPolicy {

    @Override
    public boolean isEndOfRecord(String line) {

        return StringUtils.countOccurrencesOf(line, "{") == StringUtils.countOccurrencesOf(line, "}")
                && (line.trim().endsWith("}") || line.trim().endsWith(",") || line.trim().endsWith("]"));
    }

    @Override
    public String postProcess(String record) {
        if (record.startsWith("["))
            record = record.substring(1);
        if ((record.endsWith("]") || record.endsWith(",")))
            record = record.substring(0, record.length() - 1);
        return super.postProcess(record);
    }
}

解决方案

I have created a small example for this one. Please take a look and let me know your thoughts

https://github.com/bigzidane/spring-batch-jsonListItem-reader.

For more information, I have created a Reader which is to parse JSON as a List and then map every entry to a POJO through 'classToBound' and then return each by each follow Spring Batch standard.

The example takes an Json file as

[
    {
        "name": "zidane",
        "nation": "france"
    },
    {
        "name": "ronaldo",
        "nation": "brazil"
    },
    {
        "name": "marcelo",
        "nation": "brazil"
    }
]

The job configuration

<job id="exampleJsonReaderJob" xmlns="http://www.springframework.org/schema/batch">
        <step id="stepId">
            <tasklet>
                <chunk reader="exampleJsonReader" writer="exampleWriter" processor="exampleProcessor" commit-interval="5" />
            </tasklet>
        </step>
    </job>

The Reader

<bean id="exampleJsonReader" class="com.itservicesdepot.example.springbatch.jsonreader.reader.JsonFileListItemReader" scope="step">
        <property name="resource" value="classpath:soccers.json" />
        <property name="classToBound" value="com.itservicesdepot.example.springbatch.jsonreader.model.SoccerJsonEntry" />
    </bean>

The Processor and Writer are just normal ones.

In the reader, there is an property "classToBound", that is the Pojo which is top map with an item in Json list.

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