METAMODEL-1151: Added DataContextFactory for Fixed Width files Project: http://git-wip-us.apache.org/repos/asf/metamodel/repo Commit: http://git-wip-us.apache.org/repos/asf/metamodel/commit/b38928bf Tree: http://git-wip-us.apache.org/repos/asf/metamodel/tree/b38928bf Diff: http://git-wip-us.apache.org/repos/asf/metamodel/diff/b38928bf
Branch: refs/heads/master Commit: b38928bfcf90a2266ee15d6034ea638d9b2b66d4 Parents: 689f9d9 Author: Kasper Sørensen <i.am.kasper.soren...@gmail.com> Authored: Sat Aug 5 23:08:43 2017 -0700 Committer: Kasper Sørensen <i.am.kasper.soren...@gmail.com> Committed: Sat Aug 5 23:08:43 2017 -0700 ---------------------------------------------------------------------- .../FixedWidthDataContextFactory.java | 103 +++++++++++++++++++ ....apache.metamodel.factory.DataContextFactory | 1 + 2 files changed, 104 insertions(+) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/metamodel/blob/b38928bf/fixedwidth/src/main/java/org/apache/metamodel/fixedwidth/FixedWidthDataContextFactory.java ---------------------------------------------------------------------- diff --git a/fixedwidth/src/main/java/org/apache/metamodel/fixedwidth/FixedWidthDataContextFactory.java b/fixedwidth/src/main/java/org/apache/metamodel/fixedwidth/FixedWidthDataContextFactory.java new file mode 100644 index 0000000..384bc2a --- /dev/null +++ b/fixedwidth/src/main/java/org/apache/metamodel/fixedwidth/FixedWidthDataContextFactory.java @@ -0,0 +1,103 @@ +/** + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ +package org.apache.metamodel.fixedwidth; + +import java.util.ArrayList; +import java.util.List; +import java.util.Map; + +import org.apache.metamodel.DataContext; +import org.apache.metamodel.factory.DataContextFactory; +import org.apache.metamodel.factory.DataContextProperties; +import org.apache.metamodel.factory.ResourceFactoryRegistry; +import org.apache.metamodel.util.FileHelper; +import org.apache.metamodel.util.Resource; + +/** + * {@link DataContextFactory} for {@link FixedWidthDataContext}s. + * + * In addition to supporting common properties to define resource path, encoding + * etc., this implementation expects a custom property called "columns". This + * property may take one of two forms: + * + * <ul> + * <li>A string format where column name and widths in characters are + * comma-separated. Example: "id,5,name,10,amount,7,account,5".</li> + * <li>A key/value map where keys are column names (strings) and values are + * column widths (numbers).</li> + * </ul> + */ +public class FixedWidthDataContextFactory implements DataContextFactory { + + public static final String PROPERTY_TYPE = "fixed-width"; + + @Override + public boolean accepts(DataContextProperties properties, ResourceFactoryRegistry resourceFactoryRegistry) { + return PROPERTY_TYPE.equals(properties.getDataContextType()); + } + + @SuppressWarnings("unchecked") + @Override + public DataContext create(DataContextProperties properties, ResourceFactoryRegistry resourceFactoryRegistry) { + assert accepts(properties, resourceFactoryRegistry); + + final Resource resource = resourceFactoryRegistry.createResource(properties.getResourceProperties()); + + final String encoding = getString(properties.getEncoding(), FileHelper.DEFAULT_ENCODING); + final boolean failOnInconsistentRowLength = getBoolean(properties.isFailOnInconsistentRowLength(), false); + + final List<FixedWidthColumnSpec> columnSpecs = new ArrayList<>(); + final Object columns = properties.toMap().get("columns"); + if (columns instanceof Map) { + // expect a map with column names as keys, widths as values + ((Map<String, Object>) columns).forEach((k, v) -> { + final String name = k; + final int width = ((Number) v).intValue(); + columnSpecs.add(new FixedWidthColumnSpec(name, width)); + }); + } else if (columns instanceof String) { + final String[] split = ((String) columns).split(","); + String nextName = null; + for (String token : split) { + try { + final int width = Integer.parseInt(token); + // parsing as a number worked - it must be a column width + columnSpecs.add(new FixedWidthColumnSpec(nextName, width)); + nextName = null; + } catch (NumberFormatException e) { + // parsing as a number didn't work - it must be a column + // name + nextName = token; + } + } + } + + final FixedWidthConfiguration configuration = new FixedWidthConfiguration(encoding, columnSpecs, + failOnInconsistentRowLength); + return new FixedWidthDataContext(resource, configuration); + } + + private String getString(String value, String ifNull) { + return value == null ? ifNull : value; + } + + private boolean getBoolean(Boolean value, boolean ifNull) { + return value == null ? ifNull : value; + } +} http://git-wip-us.apache.org/repos/asf/metamodel/blob/b38928bf/fixedwidth/src/main/resources/META-INF/services/org.apache.metamodel.factory.DataContextFactory ---------------------------------------------------------------------- diff --git a/fixedwidth/src/main/resources/META-INF/services/org.apache.metamodel.factory.DataContextFactory b/fixedwidth/src/main/resources/META-INF/services/org.apache.metamodel.factory.DataContextFactory new file mode 100644 index 0000000..c71922f --- /dev/null +++ b/fixedwidth/src/main/resources/META-INF/services/org.apache.metamodel.factory.DataContextFactory @@ -0,0 +1 @@ +org.apache.metamodel.fixedwidth.FixedWidthDataContextFactory \ No newline at end of file
