[CALCITE-884] Web adapter (Henry Olson)

Some fix-ups (Julian Hyde):
* Upgrade calcite;
* Upgrade natty, jsoup;
* Rename files, and move to org.apache.calcite.adapter.file package;
* Add file adapter documentation and history (based on original README
  and HISTORY);
* Add EMPS.html and DEPTS.html examples.

core/src/main/java/org/apache/calcite/schema/SchemaFactory.java

@@ -24,27 +24,27 @@
  * <p>A schema factory allows you to include a custom schema in a model file.
  * For example, here is a model that contains a custom schema whose tables
  * read CSV files. (See the
- * <a href="https://github.com/julianhyde/optiq-csv">optiq-csv</a> for more
- * details about this particular adapter.)</p>
+ * <a href="http://calcite.apache.org/apidocs/org/apache/calcite/adapter/csv/package-summary.html">example CSV adapter</a>
+ * for more details about this particular adapter.)
  *
  * <pre>{@code
  * {
- *   version: '1.0',
- *   defaultSchema: 'SALES',
- *   schemas: [
+ *   "version": "1.0",
+ *   "defaultSchema": "SALES",
+ *   "schemas": [
  *     {
- *       name: 'SALES',
- *       type: 'custom',
- *       factory: 'org.apache.calcite.adapter.csv.CsvSchemaFactory',
- *       mutable: true,
- *       operand: {
- *         directory: 'target/test-classes/sales'
+ *       "name": "SALES",
+ *       "type": "custom",
+ *       "factory": "org.apache.calcite.adapter.csv.CsvSchemaFactory",
+ *       "mutable": true,
+ *       "operand": {
+ *         directory: "target/test-classes/sales"
  *       },
- *       tables: [
+ *       "tables": [
  *         {
- *           name: 'FEMALE_EMPS',
- *           type: 'view',
- *           sql: 'SELECT * FROM emps WHERE gender = \'F\''
+ *           "name": "FEMALE_EMPS",
+ *           "type": "view",
+ *           "sql": "SELECT * FROM emps WHERE gender = 'F'"
  *          }
  *       ]
  *     }
@@ -55,10 +55,10 @@
  *
  * <p>If you do not wish to allow model authors to add additional tables
  * (including views) to an instance of your schema, specify
- * 'mutable: false'.</p>
+ * 'mutable: false'.
  *
  * <p>A class that implements SchemaFactory specified in a schema must have a
- * public default constructor.</p>
+ * public default constructor.
  */
 public interface SchemaFactory {
   /** Creates a Schema.

file/pom.xml

@@ -0,0 +1,112 @@
+<!--
+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.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 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>
+  <parent>
+    <groupId>org.apache.calcite</groupId>
+    <artifactId>calcite</artifactId>
+    <version>1.12.0-SNAPSHOT</version>
+  </parent>
+
+  <!-- The basics. -->
+  <artifactId>calcite-file</artifactId>
+  <packaging>jar</packaging>
+  <version>1.12.0-SNAPSHOT</version>
+  <name>Calcite File</name>
+  <description>Calcite provider that reads files and URIs</description>
+
+  <properties>
+    <top.dir>${project.basedir}/..</top.dir>
+    <build.timestamp>${maven.build.timestamp}</build.timestamp>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>com.google.guava</groupId>
+      <artifactId>guava</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>com.joestelmach</groupId>
+      <artifactId>natty</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.calcite</groupId>
+      <artifactId>calcite-core</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.apache.calcite</groupId>
+      <artifactId>calcite-linq4j</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>org.jsoup</groupId>
+      <artifactId>jsoup</artifactId>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <plugins>
+      <plugin>
+          <groupId>org.codehaus.mojo</groupId>
+	      <artifactId>jalopy-maven-plugin</artifactId>
+	      <version>1.0-alpha-1</version>
+	      <configuration>
+	        <srcExcludesPattern>**/CsvTableScan.java</srcExcludesPattern>
+            <failOnError>false</failOnError>
+            <convention>${top.dir}src/main/config/jalopy.xml</convention>
+	      </configuration>
+      </plugin>
+
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-surefire-plugin</artifactId>
+        <version>2.18</version>
+        <configuration>
+          <includes>
+            <include>org/apache/calcite/adapter/file/FileSuite.java</include>
+          </includes>
+        </configuration>
+      </plugin>
+
+      <plugin>
+        <groupId>org.apache.maven.plugins</groupId>
+        <artifactId>maven-dependency-plugin</artifactId>
+        <version>2.8</version>
+        <executions>
+          <execution>
+            <id>copy-dependencies</id>
+            <phase>package</phase>
+            <goals>
+              <goal>copy-dependencies</goal>
+            </goals>
+            <configuration>
+              <outputDirectory>${project.build.directory}/dependencies/</outputDirectory>
+              <overWriteReleases>false</overWriteReleases>
+              <overWriteSnapshots>false</overWriteSnapshots>
+              <overWriteIfNewer>true</overWriteIfNewer>
+            </configuration>
+          </execution>
+        </executions>
+      </plugin>
+    </plugins>
+  </build>
+
+</project>

file/src/main/java/org/apache/calcite/adapter/file/FileEnumerator.java

@@ -0,0 +1,94 @@
+/*
+ * 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.calcite.adapter.file;
+
+import org.apache.calcite.linq4j.Enumerator;
+
+import org.jsoup.select.Elements;
+
+import java.util.Iterator;
+
+/**
+ * Wraps WebReader and FileRowConverter, enumerates tr Elements as
+ * table rows.
+ */
+class FileEnumerator implements Enumerator<Object> {
+
+  private final Iterator<Elements> iterator;
+  private final FileRowConverter converter;
+  private final int[] fields;
+  private Object current;
+
+  public FileEnumerator(Iterator<Elements> iterator,
+      FileRowConverter converter) {
+    this.iterator = iterator;
+    this.converter = converter;
+    this.fields = identityList(this.converter.width());
+  }
+
+  public FileEnumerator(Iterator<Elements> iterator, FileRowConverter converter,
+      int[] fields) {
+    this.iterator = iterator;
+    this.converter = converter;
+    this.fields = fields;
+  }
+
+  public Object current() {
+    if (current == null) {
+      this.moveNext();
+    }
+    return current;
+  }
+
+  public boolean moveNext() {
+    try {
+      if (this.iterator.hasNext()) {
+        final Elements row = this.iterator.next();
+        current = this.converter.toRow(row, this.fields);
+        return true;
+      } else {
+        current = null;
+        return false;
+      }
+    } catch (Exception e) {
+      throw new RuntimeException(e);
+    }
+  }
+
+  // required by linq4j Enumerator interface
+  public void reset() {
+    throw new UnsupportedOperationException();
+  }
+
+  // required by linq4j Enumerator interface
+  public void close() {
+  }
+
+  /** Returns an array of integers {0, ..., n - 1}. */
+  private static int[] identityList(int n) {
+    int[] integers = new int[n];
+
+    for (int i = 0; i < n; i++) {
+      integers[i] = i;
+    }
+
+    return integers;
+  }
+
+}
+
+// End FileEnumerator.java

file/src/main/java/org/apache/calcite/adapter/file/FileFieldType.java

@@ -0,0 +1,86 @@
+/*
+ * 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.calcite.adapter.file;
+
+import org.apache.calcite.adapter.java.JavaTypeFactory;
+import org.apache.calcite.linq4j.tree.Primitive;
+import org.apache.calcite.rel.type.RelDataType;
+
+import com.google.common.collect.ImmutableMap;
+
+import java.util.Map;
+
+/**
+ * Type of a field in a Web (HTML) table.
+ *
+ * <p>Usually, and unless specified explicitly in the header row, a field is
+ * of type {@link #STRING}. But specifying the field type in the fields
+ * makes it easier to write SQL.
+ *
+ * <p>Trivially modified from CsvFieldType.
+ */
+enum FileFieldType {
+  STRING(null, String.class),
+  BOOLEAN(Primitive.BOOLEAN),
+  BYTE(Primitive.BYTE),
+  CHAR(Primitive.CHAR),
+  SHORT(Primitive.SHORT),
+  INT(Primitive.INT),
+  LONG(Primitive.LONG),
+  FLOAT(Primitive.FLOAT),
+  DOUBLE(Primitive.DOUBLE),
+  DATE(null, java.sql.Date.class),
+  TIME(null, java.sql.Time.class),
+  TIMESTAMP(null, java.sql.Timestamp.class);
+
+  private final Primitive primitive;
+  private final Class clazz;
+
+  private static final Map<String, FileFieldType> MAP;
+
+  static {
+    ImmutableMap.Builder<String, FileFieldType> builder =
+        ImmutableMap.builder();
+    for (FileFieldType value : values()) {
+      builder.put(value.clazz.getSimpleName(), value);
+
+      if (value.primitive != null) {
+        builder.put(value.primitive.primitiveClass.getSimpleName(), value);
+      }
+    }
+    MAP = builder.build();
+  }
+
+  FileFieldType(Primitive primitive) {
+    this(primitive, primitive.boxClass);
+  }
+
+  FileFieldType(Primitive primitive, Class clazz) {
+    this.primitive = primitive;
+    this.clazz = clazz;
+  }
+
+  public RelDataType toType(JavaTypeFactory typeFactory) {
+    return typeFactory.createJavaType(clazz);
+  }
+
+  public static FileFieldType of(String typeString) {
+    return MAP.get(typeString);
+  }
+}
+
+// End FileFieldType.java