Question

我的输入文件夹中有2个json文件。我需要读取每个json，处理它（假设我的处理器将Json值更改为大写）并将处理后的json写入输出文件夹。所以基本上对于每个json输入文件，我需要将相应的已处理JSON写入输出文件夹。我怎么能做到这一点？

下面是我输入的json文件：

雇员-list01.json

[{"firstName":"aaa", "lastName":"bbb"}, 
    {"firstName":"ccc", "lastName":"ddd"}]

雇员-list02.json

[{"firstName":"eee", "lastName":"fff"}, 
    {"firstName":"ggg", "lastName":"hhh"}]

这是我的工作配置：

<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:batch="http://www.springframework.org/schema/batch" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans 
    http://www.springframework.org/schema/beans/spring-beans-4.0.xsd
    http://www.springframework.org/schema/batch
    http://www.springframework.org/schema/batch/spring-batch-3.0.xsd">

<import resource="../config/applicationContext.xml" />

<bean id="multiResourceItemReader" class="org.springframework.batch.item.file.MultiResourceItemReader">
    <property name="resources" value="classpath:json/employee-list*.json" />
    <property name="delegate" ref="jsonFileReader" />
</bean>

<bean id="jsonFileReader" class="org.springframework.batch.item.file.FlatFileItemReader">
    <property name="recordSeparatorPolicy" ref="recordPolicy" />
    <property name="lineMapper" ref="lineMapper" />
</bean>

<bean id="recordPolicy"
    class="com.spring.batch.learnings.ComplexJsonRecordSeparatorPolicy" />

<bean id="lineMapper"
    class="com.spring.batch.learnings.EmployeeListLineMapper">
    <property name="delegate" ref="lineMapperType" />
</bean>

<bean id="lineMapperType"
    class="org.springframework.batch.item.file.mapping.JsonLineMapper" />

<bean id="multiResourceItemWriter"
class="org.springframework.batch.item.file.MultiResourceItemWriter">
    <property name="resource" value="file:json/employee-list.json" />
    <property name="itemCountLimitPerResource" value="2"/>
    <property name="saveState" value="true" />
    <property name="delegate" ref="jsonFileWriter"/>                
</bean>

<bean id="jsonFileWriter" class="org.springframework.batch.item.file.FlatFileItemWriter">
    <property name="headerCallback" ref="headerCallback" />         
    <property name="footerCallback" ref="footerCallback" />                 
    <property name="lineAggregator" ref="lineAggregator" />
</bean> 

<bean id="headerCallback"
    class="com.spring.batch.learnings.EmployeeHeaderFooterCallBack">        
</bean>

<bean id="footerCallback"
    class="com.spring.batch.learnings.EmployeeHeaderFooterCallBack">        
</bean>

<bean id="lineAggregator"
    class="com.spring.batch.learnings.EmployeeJsonItemAggregator">      
</bean> 

<bean id="itemProcessor"
    class="com.spring.batch.learnings.EmployeeListProcessor" />

<bean id="batchJobListener" class="com.spring.batch.learnings.BatchJobListener" />

<batch:job id="mySimpleJob">
    <batch:step id="step1">
        <batch:tasklet transaction-manager="transactionManager">
            <batch:chunk reader="multiResourceItemReader" writer="multiResourceItemWriter"
                processor="itemProcessor" commit-interval="1" />
        </batch:tasklet>
    </batch:step>       
    <batch:listeners>
        <batch:listener ref="batchJobListener" />
    </batch:listeners>
</batch:job>

我的EmployeeJsonItemAggregator如下所示

public class EmployeeJsonItemAggregator<Employee> implements LineAggregator<Employee> {

    private boolean isFirstObject = true;
    @Override
    public String aggregate(final Employee aEmployee) {     
        if (isFirstObject) {
            isFirstObject = false;
            return JsonUtils.convertObjectToJsonString(aEmployee);
        }

        return "," + JsonUtils.convertObjectToJsonString(aEmployee);
    }
}

JsonUtils：

public class JsonUtils {
    public static <T> String convertObjectToJsonString(T object) {

        ObjectMapper objectMapper = new ObjectMapper();
        ObjectWriter objectWriter = objectMapper.writer().withDefaultPrettyPrinter();
        String jsonString = null;
        try {
            jsonString = objectWriter.writeValueAsString(object);
        } catch (JsonProcessingException myException) {
            // TODO Auto-generated catch block
            myException.printStackTrace();
        }
        return jsonString;
    }
}

EmployeeHeaderFooterCallBack：

public class EmployeeHeaderFooterCallBack implements FlatFileHeaderCallback, FlatFileFooterCallback {

    @Override
    public void writeHeader(Writer writer) throws IOException {
        writer.write("[");      
    }

    @Override
    public void writeFooter(Writer writer) throws IOException {
        writer.write("]");      
    }
}

我能够成功读取两个JSON。此外，我能够看到已处理的JSON被写入2个单独的输出JSON文件。但我的第二个JSON输出文件正在写一个额外的＆＃34;，＆＃34;标题之后＆＃34; [＆＃34;是在开头写的。

我的输出JSON如下所示：

雇员-list.json.1

[
{
  "firstName" : "AAA",
  "lastName" : "BBB"
}
,{
  "firstName" : "CCC",
  "lastName" : "DDD"
}    
]

employee-list.json.2（你可以看到额外的＆＃34;，＆＃34;＆＃34; [＆＃34; here）我怎样才能避免这种情况？

[
,{
  "firstName" : "EEE",
  "lastName" : "FFF"
}
,{
  "firstName" : "GGG",
  "lastName" : "HHH"
}
]

另外我认为通过上述方法，批处理实际上是同时读取两个输入文件。我希望我的批处理读取输入文件，处理并写入它，然后读取下一个输入文件进行处理和写入。我怎样才能做到这一点？

输出文件必须与输入文件同名。如何配置输出以使其从输入文件中获取输出文件名？

Spring批处理：如何读写多个JSON文件

0 个答案: