ItemReader无法通过PrestoDriver读取行

问题描述

以下ItemReader bean通过PrestDriver读取行。执行批处理时，出现以下错误消息：

org.springframework.batch.core.step.skip.NonSkippableReadException: Non-skippable exception during read
at org.springframework.batch.core.step.item.FaultTolerantChunkProvider.read(FaultTolerantChunkProvider.java:105) ~[spring-batch-core-4.2.4.RELEASE.jar:4.2.4.RELEASE]
at org.springframework.batch.core.step.item.SimpleChunkProvider$1.doInIteration(SimpleChunkProvider.java:126) ~[spring-batch-core-4.2.4.RELEASE.jar:4.2.4.RELEASE]

.....

Caused by: org.springframework.dao.InvalidDataAccessApiUsageException: Attempt to process next row 
Failed; sql [SELECT * FROM ......]; getRow; nested exception is 
java.sql.sqlFeatureNotSupportedException: getRow

ItemReader代码

@Bean
public ItemReader<ExportDto> itemReader() {
    DriverManagerDataSource dataSource = new DriverManagerDataSource();
    dataSource.setDriverClassName("com.facebook.presto.jdbc.PrestoDriver");
    dataSource.setUrl("jdbc:presto: ");
    dataSource.setUsername("....");
    dataSource.setPassword("....");

    JdbcCursorItemReader<ExportDto> reader = new JdbcCursorItemReader<ExportDto>();
    reader.setDataSource(dataSource);
    reader.setsql("SELECT * FROM .....'");
    BeanPropertyRowMapper<ExportDto> rowMapper = new BeanPropertyRowMapper<>(ExportDto.class);
    reader.setRowMapper(rowMapper);
    return reader;
}

我已经创建了一个“ hello world”应用程序来测试驱动程序，这次使用普通的JDBCDriver。该测试成功。

 String url = "jdbc:presto:.....";
    Properties properties = new Properties();
    properties.setProperty("user","....");
    properties.setProperty("password","....");
    properties.setProperty("SSL","true");
    try {
        Connection conn = DriverManager.getConnection(url,properties);
        if (conn == null) {
            System.out.print("NULL");
        } else {
            Statement stmt = conn.createStatement();
            String sql = "SELECT distinct .....";
            ResultSet rs = stmt.executeQuery(sql);
            // Extract data from result set
            while (rs.next()) {
                // Retrieve by column name
                String programs = rs.getString("prg");
            }
            // Clean-up environment
            rs.close();
            stmt.close();
            conn.close();
        }

为什么会发生这种情况？或一些解决方法将不胜感激。

谢谢

解决方法

默认情况下，JdbcCursorItemReader验证光标在每个已处理行之后的位置。此检查涉及call to ResultSet#getRow()，似乎comment above中所提到的不受支持。

您可以使用JdbcCursorItemReader#setVerifyCursorPosition禁用此检查，直到Presto驱动程序支持此功能为止。