freemarker-generator-base/src/main/java/org/apache/freemarker/generator/base/datasource/DataSource.java - freemarker-generator - Git at Google

 /*
  * 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.freemarker.generator.base.datasource;

 import org.apache.commons.io.FilenameUtils;
 import org.apache.commons.io.IOUtils;
 import org.apache.commons.io.LineIterator;
 import org.apache.freemarker.generator.base.activation.ByteArrayDataSource;
 import org.apache.freemarker.generator.base.activation.StringDataSource;
 import org.apache.freemarker.generator.base.mime.MimetypeParser;
 import org.apache.freemarker.generator.base.util.CloseableReaper;

 import javax.activation.FileDataSource;
 import java.io.Closeable;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.StringWriter;
 import java.net.URI;
 import java.nio.charset.Charset;
 import java.util.List;

 import static java.nio.charset.StandardCharsets.UTF_8;
 import static java.util.Objects.requireNonNull;
 import static org.apache.commons.io.IOUtils.lineIterator;
 import static org.apache.freemarker.generator.base.FreeMarkerConstants.DATASOURCE_UNKNOWN_LENGTH;
 import static org.apache.freemarker.generator.base.util.StringUtils.emptyToNull;
 import static org.apache.freemarker.generator.base.util.StringUtils.isNotEmpty;

 /**
  * Data source which encapsulates data to be used for rendering
  * a template. When accessing content it is loaded on demand on not
  * kept in memory to allow processing of large volumes of data.
  * <br>
  * There is also special support of <code>UrlDataSource</code> since
  * the content type &amp; charset might be determined using a network
  * call.
  */
 public class DataSource implements Closeable {

     /** Human-readable name of the data source */
     private final String name;

     /** Optional group of data source */
     private final String group;

     /** The URI for loading the content of the data source */
     private final URI uri;

     /** The underlying "javax.activation.DataSource" */
     private final javax.activation.DataSource dataSource;

     /** Optional user-supplied content type */
     private final String contentType;

     /** Optional charset for directly accessing text-based content */
     private final Charset charset;

     /** Collect all closables handed out to the caller to be closed when the data source is closed itself */
     private final CloseableReaper closables;

     public DataSource(
             String name,
             String group,
             URI uri,
             javax.activation.DataSource dataSource,
             String contentType,
             Charset charset) {
         this.name = requireNonNull(name);
         this.group = emptyToNull(group);
         this.uri = requireNonNull(uri);
         this.dataSource = requireNonNull(dataSource);
         this.contentType = contentType;
         this.charset = charset;
         this.closables = new CloseableReaper();
     }

     public String getName() {
         return name;
     }

     public String getGroup() {
         return group;
     }

     public String getBaseName() {
         return FilenameUtils.getBaseName(name);
     }

     public String getExtension() {
         return FilenameUtils.getExtension(name);
     }

     public Charset getCharset() {
         return charset != null ? charset : MimetypeParser.getCharset(contentType(), UTF_8);
     }

     /**
      * Get the content type without additional parameters, e.g. "charset".
      *
      * @return content type
      */
     public String getContentType() {
         return MimetypeParser.getMimetype(contentType());
     }

     public URI getUri() {
         return uri;
     }

     /**
      * Try to get the length lazily, efficient and without consuming the input stream.
      *
      * @return Length of data source or UNKNOWN_LENGTH
      */
     public long getLength() {
         if (dataSource instanceof FileDataSource) {
             return ((FileDataSource) dataSource).getFile().length();
         } else if (dataSource instanceof StringDataSource) {
             return ((StringDataSource) dataSource).length();
         } else if (dataSource instanceof ByteArrayDataSource) {
             return ((ByteArrayDataSource) dataSource).length();
         } else {
             return DATASOURCE_UNKNOWN_LENGTH;
         }
     }

     /**
      * Get an input stream which is closed together with this data source.
      *
      * @return InputStream
      */
     public InputStream getInputStream() {
         return closables.add(getUnsafeInputStream());
     }

     /**
      * Get an input stream which needs to be closed by the caller.
      *
      * @return InputStream
      */
     public InputStream getUnsafeInputStream() {
         try {
             return dataSource.getInputStream();
         } catch (IOException e) {
             throw new RuntimeException("Failed to get input stream: " + toString(), e);
         }
     }

     public String getText() {
         return getText(getCharset().name());
     }

     public String getText(String charsetName) {
         final StringWriter writer = new StringWriter();
         try (InputStream is = getUnsafeInputStream()) {
             IOUtils.copy(is, writer, Charset.forName(charsetName));
             return writer.toString();
         } catch (IOException e) {
             throw new RuntimeException("Failed to get text: " + toString(), e);
         }
     }

     /**
      * Gets the contents of an <code>InputStream</code> as a list of Strings,
      * one entry per line, using the specified character encoding.
      *
      * @return the list of Strings, never null
      */
     public List<String> getLines() {
         return getLines(getCharset().name());
     }

     /**
      * Gets the contents of an <code>InputStream</code> as a list of Strings,
      * one entry per line, using the specified character encoding.
      *
      * @param charsetName The name of the requested charset
      * @return the list of Strings, never null
      */
     public List<String> getLines(String charsetName) {
         try (InputStream inputStream = getUnsafeInputStream()) {
             return IOUtils.readLines(inputStream, charsetName);
         } catch (IOException e) {
             throw new RuntimeException("Failed to get lines: " + toString(), e);
         }
     }

     /**
      * Returns an Iterator for the lines in an <code>InputStream</code>, using
      * the default character encoding specified. The caller is responsible to close
      * the line iterator.
      *
      * @return line iterator
      */
     public LineIterator getLineIterator() {
         return getLineIterator(getCharset().name());
     }

     /**
      * Returns an Iterator for the lines in an <code>InputStream</code>, using
      * the character encoding specified.
      *
      * @param charsetName The name of the requested charset
      * @return line iterator
      */
     public LineIterator getLineIterator(String charsetName) {
         try {
             return closables.add(lineIterator(getUnsafeInputStream(), Charset.forName(charsetName)));
         } catch (IOException e) {
             throw new RuntimeException("Failed to create line iterator: " + toString(), e);
         }
     }

     public byte[] getBytes() {
         try (InputStream inputStream = getUnsafeInputStream()) {
             return IOUtils.toByteArray(inputStream);
         } catch (IOException e) {
             throw new RuntimeException("Failed to get bytes: " + toString(), e);
         }
     }

     /**
      * Some tools create a {@link java.io.Closeable} which can bound to the
      * lifecycle of the data source. When the data source is closed all the
      * associated {@link java.io.Closeable} are closed as well.
      *
      * @param closeable Closable
      * @param <T>       Type of closable
      * @return Closable
      */
     public <T extends Closeable> T addClosable(T closeable) {
         return closables.add(closeable);
     }

     @Override
     public void close() {
         closables.close();
     }

     @Override
     public String toString() {
         return "DataSource{" +
                 "name='" + name + '\'' +
                 ", group='" + group + '\'' +
                 ", uri=" + uri +
                 '}';
     }

     private String contentType() {
         return isNotEmpty(contentType) ? contentType : dataSource.getContentType();
     }
 }
	/*
	* 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.freemarker.generator.base.datasource;

	import org.apache.commons.io.FilenameUtils;
	import org.apache.commons.io.IOUtils;
	import org.apache.commons.io.LineIterator;
	import org.apache.freemarker.generator.base.activation.ByteArrayDataSource;
	import org.apache.freemarker.generator.base.activation.StringDataSource;
	import org.apache.freemarker.generator.base.mime.MimetypeParser;
	import org.apache.freemarker.generator.base.util.CloseableReaper;

	import javax.activation.FileDataSource;
	import java.io.Closeable;
	import java.io.IOException;
	import java.io.InputStream;
	import java.io.StringWriter;
	import java.net.URI;
	import java.nio.charset.Charset;
	import java.util.List;

	import static java.nio.charset.StandardCharsets.UTF_8;
	import static java.util.Objects.requireNonNull;
	import static org.apache.commons.io.IOUtils.lineIterator;
	import static org.apache.freemarker.generator.base.FreeMarkerConstants.DATASOURCE_UNKNOWN_LENGTH;
	import static org.apache.freemarker.generator.base.util.StringUtils.emptyToNull;
	import static org.apache.freemarker.generator.base.util.StringUtils.isNotEmpty;

	/**
	* Data source which encapsulates data to be used for rendering
	* a template. When accessing content it is loaded on demand on not
	* kept in memory to allow processing of large volumes of data.
	* <br>
	* There is also special support of <code>UrlDataSource</code> since
	* the content type & charset might be determined using a network
	* call.
	*/
	public class DataSource implements Closeable {

	/** Human-readable name of the data source */
	private final String name;

	/** Optional group of data source */
	private final String group;

	/** The URI for loading the content of the data source */
	private final URI uri;

	/** The underlying "javax.activation.DataSource" */
	private final javax.activation.DataSource dataSource;

	/** Optional user-supplied content type */
	private final String contentType;

	/** Optional charset for directly accessing text-based content */
	private final Charset charset;

	/** Collect all closables handed out to the caller to be closed when the data source is closed itself */
	private final CloseableReaper closables;

	public DataSource(
	String name,
	String group,
	URI uri,
	javax.activation.DataSource dataSource,
	String contentType,
	Charset charset) {
	this.name = requireNonNull(name);
	this.group = emptyToNull(group);
	this.uri = requireNonNull(uri);
	this.dataSource = requireNonNull(dataSource);
	this.contentType = contentType;
	this.charset = charset;
	this.closables = new CloseableReaper();
	}

	public String getName() {
	return name;
	}

	public String getGroup() {
	return group;
	}

	public String getBaseName() {
	return FilenameUtils.getBaseName(name);
	}

	public String getExtension() {
	return FilenameUtils.getExtension(name);
	}

	public Charset getCharset() {
	return charset != null ? charset : MimetypeParser.getCharset(contentType(), UTF_8);
	}

	/**
	* Get the content type without additional parameters, e.g. "charset".
	*
	* @return content type
	*/
	public String getContentType() {
	return MimetypeParser.getMimetype(contentType());
	}

	public URI getUri() {
	return uri;
	}

	/**
	* Try to get the length lazily, efficient and without consuming the input stream.
	*
	* @return Length of data source or UNKNOWN_LENGTH
	*/
	public long getLength() {
	if (dataSource instanceof FileDataSource) {
	return ((FileDataSource) dataSource).getFile().length();
	} else if (dataSource instanceof StringDataSource) {
	return ((StringDataSource) dataSource).length();
	} else if (dataSource instanceof ByteArrayDataSource) {
	return ((ByteArrayDataSource) dataSource).length();
	} else {
	return DATASOURCE_UNKNOWN_LENGTH;
	}
	}

	/**
	* Get an input stream which is closed together with this data source.
	*
	* @return InputStream
	*/
	public InputStream getInputStream() {
	return closables.add(getUnsafeInputStream());
	}

	/**
	* Get an input stream which needs to be closed by the caller.
	*
	* @return InputStream
	*/
	public InputStream getUnsafeInputStream() {
	try {
	return dataSource.getInputStream();
	} catch (IOException e) {
	throw new RuntimeException("Failed to get input stream: " + toString(), e);
	}
	}

	public String getText() {
	return getText(getCharset().name());
	}

	public String getText(String charsetName) {
	final StringWriter writer = new StringWriter();
	try (InputStream is = getUnsafeInputStream()) {
	IOUtils.copy(is, writer, Charset.forName(charsetName));
	return writer.toString();
	} catch (IOException e) {
	throw new RuntimeException("Failed to get text: " + toString(), e);
	}
	}

	/**
	* Gets the contents of an <code>InputStream</code> as a list of Strings,
	* one entry per line, using the specified character encoding.
	*
	* @return the list of Strings, never null
	*/
	public List<String> getLines() {
	return getLines(getCharset().name());
	}

	/**
	* Gets the contents of an <code>InputStream</code> as a list of Strings,
	* one entry per line, using the specified character encoding.
	*
	* @param charsetName The name of the requested charset
	* @return the list of Strings, never null
	*/
	public List<String> getLines(String charsetName) {
	try (InputStream inputStream = getUnsafeInputStream()) {
	return IOUtils.readLines(inputStream, charsetName);
	} catch (IOException e) {
	throw new RuntimeException("Failed to get lines: " + toString(), e);
	}
	}

	/**
	* Returns an Iterator for the lines in an <code>InputStream</code>, using
	* the default character encoding specified. The caller is responsible to close
	* the line iterator.
	*
	* @return line iterator
	*/
	public LineIterator getLineIterator() {
	return getLineIterator(getCharset().name());
	}

	/**
	* Returns an Iterator for the lines in an <code>InputStream</code>, using
	* the character encoding specified.
	*
	* @param charsetName The name of the requested charset
	* @return line iterator
	*/
	public LineIterator getLineIterator(String charsetName) {
	try {
	return closables.add(lineIterator(getUnsafeInputStream(), Charset.forName(charsetName)));
	} catch (IOException e) {
	throw new RuntimeException("Failed to create line iterator: " + toString(), e);
	}
	}

	public byte[] getBytes() {
	try (InputStream inputStream = getUnsafeInputStream()) {
	return IOUtils.toByteArray(inputStream);
	} catch (IOException e) {
	throw new RuntimeException("Failed to get bytes: " + toString(), e);
	}
	}

	/**
	* Some tools create a {@link java.io.Closeable} which can bound to the
	* lifecycle of the data source. When the data source is closed all the
	* associated {@link java.io.Closeable} are closed as well.
	*
	* @param closeable Closable
	* @param <T> Type of closable
	* @return Closable
	*/
	public <T extends Closeable> T addClosable(T closeable) {
	return closables.add(closeable);
	}

	@Override
	public void close() {
	closables.close();
	}

	@Override
	public String toString() {
	return "DataSource{" +
	"name='" + name + '\'' +
	", group='" + group + '\'' +
	", uri=" + uri +
	'}';
	}

	private String contentType() {
	return isNotEmpty(contentType) ? contentType : dataSource.getContentType();
	}
	}