schemacrawler java.lang.NullPointerException：無法檢索目錄

Question

我嘗試將 schemacrawler 與 hsqldb 2.51 和 h2 2.x 一起使用，代碼如下：

final LimitOptionsBuilder limit = LimitOptionsBuilder.builder()
    .includeSchemas(new IncludeAll())
    .includeTables(new IncludeAll());
final LoadOptionsBuilder load = LoadOptionsBuilder.builder()
    .withSchemaInfoLevel(SchemaInfoLevelBuilder.minimum());
final SchemaCrawlerOptions options = SchemaCrawlerOptionsBuilder.newSchemaCrawlerOptions()
    .withLimitOptions(limit.toOptions())
    .withLoadOptions(load.toOptions());
final Catalog catalog = SchemaCrawlerUtility.getCatalog(connection, options);
// throw NullPointerException
for (final schemacrawler.schema.Table t : catalog.getTables())
{
    //more code...
}

如果沒有 NullPointerException 錯誤，我將無法獲取目錄。 我在類路徑中有兩個檔案：

• schemacrawler-16.16.11.jar
• schemacrawler-hsqldb-16.16.11.jar

如果有人有想法...

Answer 1

在更改了一些代碼后，我設法得到了一些有用的東西......

new LoggingConfig(Level.ALL);
final LimitOptionsBuilder limit = LimitOptionsBuilder.builder()
    .includeSchemas(new IncludeAll())
    .includeTables(new IncludeAll());
final LoadOptionsBuilder load = LoadOptionsBuilder.builder()
    .withSchemaInfoLevel(SchemaInfoLevelBuilder.minimum());
final SchemaCrawlerOptions options = SchemaCrawlerOptionsBuilder.newSchemaCrawlerOptions()
    .withLimitOptions(limit.toOptions())
    .withLoadOptions(load.toOptions()); 
final SchemaRetrievalOptions retrieval = SchemaCrawlerUtility.matchSchemaRetrievalOptions(connection);
schemacrawler.crawl.SchemaCrawler crawler = new schemacrawler.crawl.SchemaCrawler(connection, retrieval, options);
final Catalog catalog = crawler.crawl();
for (final schemacrawler.schema.Table t : catalog.getTables())
    {
        //more code...
    }

但是，第一個代碼總是給我同樣的錯誤......