[🍒][CDAP-21093] Add ExternalDocumentationLink in abstract sink

cloudsql-mysql-plugin/src/main/java/io/cdap/plugin/cloudsql/mysql/CloudSQLMySQLSink.java

@@ -108,6 +108,11 @@ protected String getErrorDetailsProviderClassName() {
     return CloudSQLMySQLErrorDetailsProvider.class.getName();
   }
 
+  @Override
+  protected String getExternalDocumentationLink() {
+    return DBUtils.CLOUDSQLMYSQL_SUPPORTED_DOC_URL;
+  }
+
   @Override
   protected LineageRecorder getLineageRecorder(BatchSinkContext context) {
     String host;

cloudsql-postgresql-plugin/src/main/java/io/cdap/plugin/cloudsql/postgres/CloudSQLPostgreSQLSink.java

@@ -152,6 +152,11 @@ protected String getErrorDetailsProviderClassName() {
     return CloudSQLPostgreSQLErrorDetailsProvider.class.getName();
   }
 
+  @Override
+  protected String getExternalDocumentationLink() {
+    return DBUtils.CLOUDSQLPOSTGRES_SUPPORTED_DOC_URL;
+  }
+
   /** CloudSQL PostgreSQL sink config. */
   public static class CloudSQLPostgreSQLSinkConfig extends AbstractDBSpecificSinkConfig {
 

database-commons/src/main/java/io/cdap/plugin/db/sink/AbstractDBSink.java

@@ -25,6 +25,10 @@
 import io.cdap.cdap.api.data.format.StructuredRecord;
 import io.cdap.cdap.api.data.schema.Schema;
 import io.cdap.cdap.api.dataset.lib.KeyValue;
+import io.cdap.cdap.api.exception.ErrorCategory;
+import io.cdap.cdap.api.exception.ErrorCodeType;
+import io.cdap.cdap.api.exception.ErrorType;
+import io.cdap.cdap.api.exception.ErrorUtils;
 import io.cdap.cdap.api.plugin.PluginConfig;
 import io.cdap.cdap.etl.api.Emitter;
 import io.cdap.cdap.etl.api.FailureCollector;
@@ -175,6 +179,16 @@ protected String getErrorDetailsProviderClassName() {
     return DBErrorDetailsProvider.class.getName();
   }
 
+  /**
+   * Returns the external documentation link.
+   * Override this method to provide a custom external documentation link.
+   *
+   * @return external documentation link
+   */
+  protected String getExternalDocumentationLink() {
+    return null;
+  }
+
   @Override
   public void prepareRun(BatchSinkContext context) {
     String connectionString = dbSinkConfig.getConnectionString();
@@ -296,8 +310,21 @@ private Schema inferSchema(Class<? extends Driver> driverClass) {
           inferredFields.addAll(getSchemaReader().getSchemaFields(rs));
         }
       } catch (SQLException e) {
-        throw new InvalidStageException("Error while reading table metadata", e);
-
+        // wrap exception to ensure SQLException-child instances not exposed to contexts w/o jdbc driver in classpath
+        String errorMessageWithDetails = String.format("Error while reading table metadata." +
+          "Error message: '%s'. Error code: '%s'. SQLState: '%s'", e.getMessage(), e.getErrorCode(), e.getSQLState());
+        String externalDocumentationLink = getExternalDocumentationLink();
+        if (!Strings.isNullOrEmpty(externalDocumentationLink)) {
+          if (!errorMessageWithDetails.endsWith(".")) {
+            errorMessageWithDetails = errorMessageWithDetails + ".";
+          }
+          errorMessageWithDetails = String.format("%s For more details, see %s", errorMessageWithDetails,
+            externalDocumentationLink);
+        }
+        throw ErrorUtils.getProgramFailureException(new ErrorCategory(ErrorCategory.ErrorCategoryEnum.PLUGIN),
+          e.getMessage(), errorMessageWithDetails, ErrorType.USER, false, ErrorCodeType.SQLSTATE,
+          e.getSQLState(), externalDocumentationLink, new SQLException(e.getMessage(),
+            e.getSQLState(), e.getErrorCode()));
       }
     } catch (IllegalAccessException | InstantiationException | SQLException e) {
       throw new InvalidStageException("JDBC Driver unavailable: " + dbSinkConfig.getJdbcPluginName(), e);

database-commons/src/main/java/io/cdap/plugin/db/source/AbstractDBSource.java

@@ -373,6 +373,12 @@ protected Class<? extends DBWritable> getDBRecordType() {
     return DBRecord.class;
   }
 
+  /**
+   * Returns the external documentation link.
+   * Override this method to provide a custom external documentation link.
+   *
+   * @return external documentation link
+   */
   protected String getExternalDocumentationLink() {
     return null;
   }

mysql-plugin/src/main/java/io/cdap/plugin/mysql/MysqlSink.java

@@ -114,6 +114,11 @@ protected String getErrorDetailsProviderClassName() {
     return MysqlErrorDetailsProvider.class.getName();
   }
 
+  @Override
+  protected String getExternalDocumentationLink() {
+    return DBUtils.MYSQL_SUPPORTED_DOC_URL;
+  }
+
   /**
    * MySQL action configuration.
    */

postgresql-plugin/src/main/java/io/cdap/plugin/postgres/PostgresSink.java

@@ -121,6 +121,11 @@ protected String getErrorDetailsProviderClassName() {
     return PostgresErrorDetailsProvider.class.getName();
   }
 
+  @Override
+  protected String getExternalDocumentationLink() {
+    return DBUtils.POSTGRES_SUPPORTED_DOC_URL;
+  }
+
   /**
    * PostgreSQL action configuration.
    */