com.espertech.esperio.csv.AdapterInputSource Maven / Gradle / Ivy
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/*
***************************************************************************************
* Copyright (C) 2006 EsperTech, Inc. All rights reserved. *
* http://www.espertech.com/esper *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
***************************************************************************************
*/
package com.espertech.esperio.csv;
import com.espertech.esper.common.client.EPException;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.Reader;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Enumeration;
import java.util.NoSuchElementException;
import java.util.zip.ZipEntry;
import java.util.zip.ZipFile;
/**
* An input source for adapters.
*/
public class AdapterInputSource {
private final URL url;
private final String classpathResource;
private final File file;
private final InputStream inputStream;
private final Reader reader;
private ZipFile zipFile;
/**
* Ctor.
*
* @param classpathResource - the name of the resource on the classpath to use as the source for an adapter
*/
public AdapterInputSource(String classpathResource) {
if (classpathResource == null) {
throw new NullPointerException("Cannot create AdapterInputStream from a null classpathResource");
}
this.classpathResource = classpathResource;
this.url = null;
this.file = null;
this.inputStream = null;
this.reader = null;
}
/**
* Ctor.
*
* @param url - the URL for the resource to use as source for an adapter
*/
public AdapterInputSource(URL url) {
if (url == null) {
throw new NullPointerException("Cannot create AdapterInputStream from a null URL");
}
this.url = url;
this.classpathResource = null;
this.file = null;
this.inputStream = null;
this.reader = null;
}
/**
* Ctor.
*
* @param file - the file to use as a source
*/
public AdapterInputSource(File file) {
if (file == null) {
throw new NullPointerException("file cannot be null");
}
this.file = file;
this.url = null;
this.classpathResource = null;
this.inputStream = null;
this.reader = null;
}
/**
* Ctor.
*
* @param inputStream - the stream to use as a source
*/
public AdapterInputSource(InputStream inputStream) {
if (inputStream == null) {
throw new NullPointerException("stream cannot be null");
}
this.inputStream = inputStream;
this.file = null;
this.url = null;
this.classpathResource = null;
this.reader = null;
}
/**
* Ctor.
*
* @param reader is any reader for reading a file or string
*/
public AdapterInputSource(Reader reader) {
if (reader == null) {
throw new NullPointerException("reader cannot be null");
}
this.reader = reader;
this.url = null;
this.classpathResource = null;
this.file = null;
this.inputStream = null;
}
/**
* Get the resource as an input stream. If this resource was specified as an InputStream,
* return that InputStream, otherwise, create and return a new InputStream from the
* resource. If the source cannot be converted to a stream, return null.
*
* @return a stream from the resource
*/
public InputStream getAsStream() {
if (reader != null) {
return null;
}
if (inputStream != null) {
return inputStream;
}
if (file != null) {
if (file.getName().endsWith("zip")) {
return openZipFile(file);
}
try {
return file.toURL().openStream();
} catch (IOException e) {
throw new EPException(e);
}
}
if (url != null) {
if (url.toString().endsWith("zip")) {
return openZipUrl(url);
}
try {
return url.openStream();
} catch (IOException e) {
throw new EPException(e);
}
} else {
return resolvePathAsStream(classpathResource);
}
}
/**
* Return the reader if it was set, null otherwise.
*
* @return the Reader
*/
public Reader getAsReader() {
return reader;
}
/**
* Return true if calling getStream() will return a new InputStream created from the
* resource, which, assuming that the resource hasn't been changed, will have the same
* information as all the previous InputStreams returned by getStream() before they were
* manipulated; return false if the call will return the same instance of InputStream that
* has already been obtained.
*
* @return true if each call to getStream() will create a new InputStream from the
* resource, false if each call will get the same instance of the InputStream
*/
public boolean isResettable() {
return inputStream == null && reader == null;
}
private InputStream resolvePathAsStream(String path) {
if (path.endsWith(".zip")) {
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
URL url = null;
if (classLoader != null) {
url = classLoader.getResource(path);
}
if (url == null) {
url = CSVReader.class.getResource(path);
}
if (url == null) {
url = CSVReader.class.getClassLoader().getResource(path);
}
if (url == null) {
throw new EPException("Resource '" + path + "' not found in classpath");
}
return openZipUrl(url);
}
InputStream stream = null;
ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
if (classLoader != null) {
stream = classLoader.getResourceAsStream(path);
}
if (stream == null) {
stream = CSVReader.class.getResourceAsStream(path);
}
if (stream == null) {
stream = CSVReader.class.getClassLoader().getResourceAsStream(path);
}
if (stream == null) {
throw new EPException("Resource '" + path + "' not found in classpath");
}
return stream;
}
private InputStream openZipUrl(URL url) {
File file;
try {
file = new File(url.toURI());
} catch (URISyntaxException e) {
throw new EPException("Resource '" + url + "' did not return a file uri: " + e.getMessage(), e);
}
return openZipFile(file);
}
private InputStream openZipFile(File file) {
try {
zipFile = new ZipFile(file);
} catch (IOException e) {
throw new EPException("Resource '" + file + "' could not be opened as a valid zip file: " + e.getMessage(), e);
}
Enumeration entry = zipFile.entries();
ZipEntry zipEntry;
try {
zipEntry = entry.nextElement();
} catch (NoSuchElementException ex) {
closeZip();
throw new EPException("Zip archive '" + file + "' is empty");
}
try {
return zipFile.getInputStream(zipEntry);
} catch (IOException ex) {
throw new EPException("Zip archive '" + file + "' entry '" + zipEntry.getName() + " could not be opened for reading");
}
}
public void close() {
closeZip();
}
private synchronized void closeZip() {
if (zipFile != null) {
try {
zipFile.close();
} catch (IOException e) {
}
zipFile = null;
}
}
}
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