com.espertech.esperio.AdapterInputSource Maven / Gradle / Ivy
/**************************************************************************************
* Copyright (C) 2006-2015 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;
import com.espertech.esper.client.EPException;
import com.espertech.esperio.csv.CSVReader;
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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