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A set of utilities and tools to speed up and ease programming in Java.
/*
* (c) 2005 David B. Bracewell
*
* 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 com.davidbracewell.conversion;
import com.davidbracewell.io.Resources;
import com.davidbracewell.io.resource.*;
import com.davidbracewell.logging.Logger;
import com.google.common.base.Function;
import com.google.common.primitives.Bytes;
import java.io.*;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.sql.Blob;
import java.sql.SQLException;
import java.util.Arrays;
/**
* Functions for converting objects into IO related objects
*
* @author David B. Bracewell
*/
public final class IOConverter {
/**
* Converts an object to a Charset
*/
public static final Function CHARSET = new Function() {
@Override
public Charset apply(Object input) {
if (input == null) {
return null;
} else if (input instanceof Charset) {
return Cast.as(input);
} else if (input instanceof CharSequence) {
try {
return Charset.forName(input.toString());
} catch (Exception e) {
log.fine("Error creating charset for name '{0}': {1}", input, e);
return null;
}
}
log.fine("Unable to convert '{0}' into a charset. Returning default charset", input.getClass());
return null;
}
};
/**
* Converts an object to a File
*/
public static final Function FILE = new Function() {
@Override
public File apply(Object input) {
if (input == null) {
return null;
} else if (input instanceof File) {
return Cast.as(input);
} else if (input instanceof Path) {
return Cast.as(input, Path.class).toFile();
} else if (input instanceof URI) {
return new File(Cast.as(input, URI.class));
} else if (input instanceof URL) {
try {
return new File(Cast.as(input, URL.class).toURI());
} catch (Exception e) {
log.fine("Error converting URL to File: {0}", e);
return null;
}
} else if (input instanceof CharSequence) {
return new File(input.toString());
}
log.fine("Unable to convert '{0}' into a File.", input.getClass());
return null;
}
};
/**
* Converts an object to an InputStream
*/
public static final Function INPUT_STREAM = new Function() {
@Override
public InputStream apply(Object input) {
if (input == null) {
return null;
} else if (input instanceof InputStream) {
return Cast.as(input);
} else if (input instanceof File) {
try {
return new FileInputStream(Cast.as(input, File.class));
} catch (FileNotFoundException e) {
log.fine(e);
return null;
}
} else if (input instanceof Path) {
try {
return Files.newInputStream(Cast.as(input, Path.class));
} catch (IOException e) {
log.fine(e);
return null;
}
} else if (input instanceof URI) {
try {
return Cast.as(input, URI.class).toURL().openStream();
} catch (IOException e) {
log.fine(e);
return null;
}
} else if (input instanceof URL) {
try {
return Cast.as(input, URL.class).openStream();
} catch (IOException e) {
log.fine(e);
return null;
}
} else if (input instanceof CharSequence) {
return new ByteArrayInputStream(input.toString().getBytes());
} else if (input instanceof char[]) {
return new ByteArrayInputStream(new String(Cast.as(input)).getBytes());
} else if (input instanceof Character[]) {
return new ByteArrayInputStream(new String(Convert.convert(input, char[].class)).getBytes());
} else if (input instanceof byte[]) {
return new ByteArrayInputStream(Cast.as(input));
} else if (input instanceof Byte[]) {
return new ByteArrayInputStream(Bytes.toArray(Arrays.asList(Cast.as(input))));
} else if (input instanceof Blob) {
try {
return Cast.as(input).getBinaryStream();
} catch (SQLException e) {
log.fine("SQL Exception reading blob: {0}", e);
return null;
}
} else if (input instanceof Iterable) {
byte[] bytes = Convert.convert(input, byte[].class);
if (bytes != null) {
return new ByteArrayInputStream(bytes);
}
}
log.fine("Unable to convert '{0}' into an InputStream.", input.getClass());
return null;
}
};
/**
* Converts an object to an OutputStream
*/
public static final Function OUTPUT_STREAM = new Function() {
@Override
public OutputStream apply(Object input) {
if (input == null) {
return null;
} else if (input instanceof OutputStream) {
return Cast.as(input);
} else if (input instanceof Path) {
try {
return new FileOutputStream(Cast.as(input, Path.class).toFile());
} catch (FileNotFoundException e) {
log.fine(e);
return null;
}
} else if (input instanceof File) {
try {
return new FileOutputStream(Cast.as(input, File.class));
} catch (FileNotFoundException e) {
log.fine(e);
return null;
}
}
log.fine("Unable to convert '{0}' into an OutputStream.", input.getClass());
return null;
}
};
/**
* Converts an object to a Path
*/
public static final Function PATH = new Function() {
@Override
public Path apply(Object input) {
if (input == null) {
return null;
} else if (input instanceof Path) {
return Cast.as(input);
} else if (input instanceof File) {
return Paths.get(Cast.as(input, File.class).getPath());
} else if (input instanceof URI) {
return Paths.get(Cast.as(input, URI.class));
} else if (input instanceof URL) {
try {
return Paths.get(Cast.as(input, URL.class).toURI());
} catch (URISyntaxException e) {
log.fine("Error converting URL to Path: {0}", e);
return null;
}
} else if (input instanceof CharSequence) {
return Paths.get(input.toString());
}
log.fine("Unable to convert '{0}' into a Path.", input.getClass());
return null;
}
};
/**
* Converts an object to a Reader
*/
public static final Function READER = new Function() {
@Override
public Reader apply(Object input) {
if (input == null) {
return null;
} else if (input instanceof Reader) {
return Cast.as(input);
}
InputStream is = INPUT_STREAM.apply(input);
if (is != null) {
return new InputStreamReader(is, StandardCharsets.UTF_8);
}
log.fine("Unable to convert '{0}' into an Writer.", input.getClass());
return null;
}
};
public static final Function RESOUCE = new Function() {
@Override
public Resource apply(Object obj) {
if (obj == null) {
return null;
}
if (obj instanceof Resource) {
return Cast.as(obj);
}
if (obj instanceof File) {
return Resources.fromFile((File) obj);
}
if (obj instanceof URL) {
return Resources.fromUrl((URL) obj);
}
if (obj instanceof URI) {
try {
return Resources.fromUrl(((URI) obj).toURL());
} catch (MalformedURLException e) {
log.fine("Error converting to URL: {0}", e);
return null;
}
}
if (obj instanceof Reader) {
return new ReaderResource(Cast.as(obj));
}
if (obj instanceof InputStream) {
return new InputStreamResource(Cast.as(obj));
}
if (obj instanceof OutputStream) {
return new OutputStreamResource(Cast.as(obj));
}
if (obj instanceof byte[]) {
return new ByteArrayResource(Cast.as(obj));
}
if (obj instanceof CharSequence) {
return Resources.from(obj.toString());
}
log.fine("Could not convert {0} into a Resource", obj.getClass());
return null;
}
};
/**
* Converts an object to a URI
*/
public static final Function URI = new Function() {
@Override
public URI apply(Object input) {
if (input == null) {
return null;
} else if (input instanceof URI) {
return Cast.as(input);
} else if (input instanceof Path) {
return Cast.as(input, Path.class).toUri();
} else if (input instanceof File) {
return Cast.as(input, File.class).toURI();
} else if (input instanceof URL) {
try {
return Cast.as(input, URL.class).toURI();
} catch (URISyntaxException e) {
log.fine("Error converting URL to URI: {0}", e);
return null;
}
} else if (input instanceof CharSequence) {
try {
return new URI(input.toString());
} catch (URISyntaxException e) {
log.fine("Error converting String to URI: {0}", e);
return null;
}
}
log.fine("Unable to convert '{0}' into a URI.", input.getClass());
return null;
}
};
/**
* Converts an object to a URL
*/
public static final Function URL = new Function() {
@Override
public URL apply(Object input) {
if (input == null) {
return null;
} else if (input instanceof URL) {
return Cast.as(input);
} else if (input instanceof Path) {
try {
return Cast.as(input, Path.class).toUri().toURL();
} catch (MalformedURLException e) {
log.fine("Error converting Path into URL: {0}", e);
return null;
}
} else if (input instanceof File) {
try {
return Cast.as(input, File.class).toURI().toURL();
} catch (MalformedURLException e) {
log.fine("Error converting File into URL: {0}", e);
return null;
}
} else if (input instanceof CharSequence) {
try {
return new URL(input.toString());
} catch (MalformedURLException e) {
log.fine("Error converting String into URL: {0}", e);
return null;
}
} else if (input instanceof URI) {
try {
return Cast.as(input, URI.class).toURL();
} catch (MalformedURLException e) {
log.fine("Error converting URI into URL: {0}", e);
return null;
}
}
log.fine("Unable to convert '{0}' into a URL.", input.getClass());
return null;
}
};
/**
* Converts an object to a Writer
*/
public static final Function WRITER = new Function() {
@Override
public Writer apply(Object input) {
if (input == null) {
return null;
} else if (input instanceof Writer) {
return Cast.as(input);
}
OutputStream stream = OUTPUT_STREAM.apply(input);
if (stream != null) {
return new OutputStreamWriter(stream, StandardCharsets.UTF_8);
}
log.fine("Unable to convert '{0}' into an Writer.", input.getClass());
return null;
}
};
private static final Logger log = Logger.getLogger(IOConverter.class);
private IOConverter() {
}
}//END OF IOConverter
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