Spring Batch rowMapper：找不到匹配的编辑器或转换策略-Java 学习之路

我正在尝试运行我的第一个Batch Spring应用程序但是我在运行时遇到了行映射器的问题：

无法将[com.tutoref.batch.ProductMapper]类型的值转换为属性“rowMapper”所需的类型[org.springframework.jdbc.core.RowMapper]：找不到匹配的编辑器或转换策略

程序必须将我的sql中的一些数据导出到平面文件（csv） . 在下面我包括主文件（如果需要，我可以添加任何文件） . 我也关注我的pom.xml中的版本 .

我的IDE是eclipse . 这是我的pom.xml：

<project xmlns="http://maven.apache.org/POM/4.0.0" 
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0         http://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>

  <groupId>com.tutoref</groupId>
  <artifactId>spring-batch-example</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <packaging>jar</packaging>

  <name>spring-batch-example</name>
  <url>http://maven.apache.org</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
  </properties>

  <dependencies>
    <!-- Spring core -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-core</artifactId>
        <version>4.3.10.RELEASE</version>
    </dependency>
    <!-- Spring batch core -->
    <dependency>
        <groupId>org.springframework.batch</groupId>
        <artifactId>spring-batch-core</artifactId>
        <version>3.0.8.RELEASE</version>
    </dependency>
    <!-- MySQL connector -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>6.0.6</version>
    </dependency>
    <!-- Spring jdbc -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>4.3.10.RELEASE</version>
    </dependency>
    <!-- The JAXB Api -->
    <dependency>
        <groupId>javax.xml.bind</groupId>
        <artifactId>jaxb-api</artifactId>
        <version>2.2.6</version>
    </dependency>
    <!-- Junit for unit testing -->
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>3.8.1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>
</project>

我的工作定义xml：

<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/batch
        http://www.springframework.org/schema/batch/spring-batch-2.2.xsd
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd
    ">

    <import resource="spring-context.xml" />
    <import resource="datasource.xml" />

    <bean id="product" class="com.tutoref.batch.entity.Product" scope="prototype" />
    <bean id="itemProcessor" class="com.tutoref.batch.ProductItemProcessor" />
    <bean id="jobListener" class="com.tutoref.batch.ProductJobListener" />


    <!-- Reading from the database and returning a mapper row -->
    <bean id="productItemReader"
        class="org.springframework.batch.item.database.JdbcCursorItemReader">
        <property name="dataSource" ref="productDataSource" />
        <property name="sql" value="SELECT * FROM products" />
        <property name="rowMapper">
            <bean class="com.tutoref.batch.ProductMapper" />
        </property>

    </bean>

    <!-- Writing a line into an output flat file -->
    <bean id="productFlatFileItemWriter" class="org.springframework.batch.item.file.FlatFileItemWriter" scope="step">
        <property name="resource" value="file:csv/products.csv" />
        <!-- Converting a product object into delimited list of strings -->
        <property name="lineAggregator">
            <bean class="org.springframework.batch.item.file.transform.DelimitedLineAggregator">
                <property name="delimiter" value="|" />
                <property name="fieldExtractor">
                    <!-- Returning the value of beans property using reflection -->
                    <bean class="org.springframework.batch.item.file.transform.BeanWrapperFieldExtractor">
                        <property name="names" value="name,unitPrice,quantity" />
                    </bean>
                </property>
            </bean>
        </property>
    </bean>

    <!-- And finally ... the job definition -->
    <batch:job id="productJob">
        <batch:step id="step1">
            <batch:tasklet transaction-manager="transactionManager">
                <batch:chunk reader="productItemReader" writer="productFlatFileItemWriter"
                    processor="itemProcessor" commit-interval="10" />
            </batch:tasklet>
        </batch:step>
        <batch:listeners>
            <batch:listener ref="jobListener" />
        </batch:listeners>
    </batch:job>
</beans>

行映射器代码：

public class ProductMapper implements FieldSetMapper<Product> {

    @Override
    public Product mapFieldSet(FieldSet fieldSet) throws BindException {
        Product product = new Product();
        product.setId(fieldSet.readInt(0));
        product.setName(fieldSet.readString(1));
        product.setQuantity(fieldSet.readInt(2));
        product.setUnitPrice(fieldSet.readDouble(3));
        return product;
    }


}

而主要课程：

public class App 
{
    public static void main(String[] args){

        ApplicationContext context = new ClassPathXmlApplicationContext("job-products.xml");

        JobLauncher jobLauncher = (JobLauncher) context.getBean("jobLauncher");
        Job job = (Job) context.getBean("productJob");

        try {
            JobExecution execution = jobLauncher.run(job, new JobParameters());
            System.out.println("Job Exit Status : "+ execution.getStatus());

        } catch (JobExecutionException e) {
            System.out.println("The Job has failed :" + e.getMessage());
            e.printStackTrace();
        }

    }
}

异常的堆栈跟踪：

INFO：没有设置TaskExecutor，默认为同步执行程序 . 加载类com.mysql.jdbc.Driver' . 这已被弃用 . 新的驱动程序类是com.mysql.cj.jdbc.Driver' . 驱动程序通过SPI自动注册，通常不需要手动加载驱动程序类 . 2017年7月30日下午2:09:59 org.springframework.jdbc.datasource.DriverManagerDataSource setDriverClassName INFO：已加载的JDBC驱动程序：com.mysql.jdbc.Driver线程“main”中的异常org.springframework.beans.factory.BeanCreationException：Error创建在类路径资源[job-products.xml]中定义的名为'productItemReader'的bean：bean的初始化失败;嵌套异常是org.springframework.beans.ConversionNotSupportedException：无法将类型'com.tutoref.batch.ProductMapper'的属性值转换为属性'rowMapper'所需的类型'org.springframework.jdbc.core.RowMapper';嵌套异常是java.lang.IllegalStateException：无法将[com.tutoref.batch.ProductMapper]类型的值转换为属性'rowMapper'所需的类型[org.springframework.jdbc.core.RowMapper]：找不到匹配的编辑器或转换策略在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean（AbstractAutowireCapableBeanFactory.java:547）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.createBean（AbstractAutowireCapableBeanFactory.java:475）在org.springframework.beans.factory .support.AbstractBeanFactory $ 1.getObject（AbstractBeanFactory.java:304）org.springframework.beans.factory.support.DefaultSingletonBeanRegistry.getSingleton（DefaultSingletonBeanRegistry.java:228）org.springframework.beans.factory.support.AbstractBeanFactory.doGetBean（在org.springframework.beans.factor的org.springframework.beans.factory.support.AbstractBeanFactory.getBean（AbstractBeanFactory.java:195）上的AbstractBeanFactory.java:300） y.support.DefaultListableBeanFactory.preInstantiateSingletons（DefaultListableBeanFactory.java:703）org.springframework.context.support.AbstractApplicationContext.finishBeanFactoryInitialization（AbstractApplicationContext.java:760）org.springframework.context.support.AbstractApplicationContext.refresh（AbstractApplicationContext.java： 482）atg.springframework.context.support.ClassPathXmlApplicationContext . （ClassPathXmlApplicationContext.java:139）atg.springframework.context.support.ClassPathXmlApplicationContext . （ClassPathXmlApplicationContext.java:83）at com.tutoref.batch.App.main（App .java：19）引起：org.springframework.beans.ConversionNotSupportedException：无法将类型'com.tutoref.batch.ProductMapper'的属性值转换为属性'rowMapper'所需的类型'org.springframework.jdbc.core.RowMapper' “;嵌套异常是java.lang.IllegalStateException：无法将[com.tutoref.batch.ProductMapper]类型的值转换为属性'rowMapper'所需的类型[org.springframework.jdbc.core.RowMapper]：找不到匹配的编辑器或转换策略org.springframework.beans.BeanWrapperImpl.convertIfNecessary（BeanWrapperImpl.java:474）org.springframework.beans.BeanWrapperImpl.convertForProperty（BeanWrapperImpl.java:511）org.springframework.beans.BeanWrapperImpl.convertForProperty（BeanWrapperImpl.java:505））在在org.springframework.beans org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.convertForProperty（AbstractAutowireCapableBeanFactory.java:1502）在org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.applyPropertyValues（AbstractAutowireCapableBeanFactory.java:1461） . factory.support.AbstractAutowireCapableBeanFactory.populateBean（AbstractAutowireCapableBeanFactory.java:1197）at atorg.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.doCreateBean（AbstractAutowireCapableBeanFactory.java:537）... 11更多引起：java.lang.IllegalStateException：无法将[com.tutoref.batch.ProductMapper]类型的值转换为必需输入属性'rowMapper'的[org.springframework.jdbc.core.RowMapper]：在org.springframework.beans.BeanWrapperImpl的org.springframework.beans.TypeConverterDelegate.convertIfNecessary（TypeConverterDelegate.java:267）中找不到匹配的编辑器或转换策略.convertIfNecessary（BeanWrapperImpl.java:459）......还有17个

谢谢

1 回答

2
无法将[com.tutoref.batch.ProductMapper]类型的值转换为属性“rowMapper”所需的类型[org.springframework.jdbc.core.RowMapper]：找不到匹配的编辑器或转换策略

此异常意味着 productItemReader bean正在等待 rowmapper 属性中的 org.springframework.jdbc.core.RowMapper 对象，但它正在接收 com.tutoref.batch.ProductMapper 类型的引用对象 .

问题出在 public class ProductMapper implements FieldSetMapper<Product>

转到ProductMapper类并实现org.springframework.jdbc.core.RowMapper而不是 FieldSetMapper

这是一个实现RowMapper接口，MessageContainer如何在项目中像 Product 类这样的pojo示例的示例 .
```
public class MessageContainerMapper implements RowMapper<MessageContainer> {

    @Override
    public MessageContainer mapRow(ResultSet rs, int rowNum) throws SQLException {
        MessageContainer mc = new MessageContainer();
        mc.setId(rs.getInt("id"));
        mc.setName(rs.getString("name"));
        return mc;
    }

}
```
回复于 2024-04-26T10:23:46+08:00

Spring Batch rowMapper：找不到匹配的编辑器或转换策略

1 回答

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