/**
* 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.camel.component.file;
import java.io.File;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;
import org.apache.camel.Exchange;
import org.apache.camel.Expression;
import org.apache.camel.impl.DefaultExchange;
import org.apache.camel.impl.DefaultProducer;
import org.apache.camel.spi.Language;
import org.apache.camel.util.FileUtil;
import org.apache.camel.util.LRUCache;
import org.apache.camel.util.ObjectHelper;
import org.apache.camel.util.ServiceHelper;
import org.apache.camel.util.StringHelper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Generic file producer
*/
public class GenericFileProducer<T> extends DefaultProducer {
protected final transient Logger log = LoggerFactory.getLogger(getClass());
protected final GenericFileEndpoint<T> endpoint;
protected GenericFileOperations<T> operations;
// assume writing to 100 different files concurrently at most for the same file producer
private final LRUCache<String, Lock> locks = new LRUCache<String, Lock>(100);
protected GenericFileProducer(GenericFileEndpoint<T> endpoint, GenericFileOperations<T> operations) {
super(endpoint);
this.endpoint = endpoint;
this.operations = operations;
}
public String getFileSeparator() {
return File.separator;
}
public String normalizePath(String name) {
return FileUtil.normalizePath(name);
}
public void process(Exchange exchange) throws Exception {
// store any existing file header which we want to keep and propagate
final String existing = exchange.getIn().getHeader(Exchange.FILE_NAME, String.class);
// create the target file name
String target = createFileName(exchange);
// use lock for same file name to avoid concurrent writes to the same file
// for example when you concurrently append to the same file
Lock lock;
synchronized (locks) {
lock = locks.get(target);
if (lock == null) {
lock = new ReentrantLock();
locks.put(target, lock);
}
}
lock.lock();
try {
processExchange(exchange, target);
} finally {
// do not remove as the locks cache has an upper bound
// this ensure the locks is appropriate reused
lock.unlock();
// and remove the write file name header as we only want to use it once (by design)
exchange.getIn().removeHeader(Exchange.OVERRULE_FILE_NAME);
// and restore existing file name
exchange.getIn().setHeader(Exchange.FILE_NAME, existing);
}
}
/**
* Sets the operations to be used.
* <p/>
* Can be used to set a fresh operations in case of recovery attempts
*
* @param operations the operations
*/
public void setOperations(GenericFileOperations<T> operations) {
this.operations = operations;
}
/**
* Perform the work to process the fileExchange
*
* @param exchange fileExchange
* @param target the target filename
* @throws Exception is thrown if some error
*/
protected void processExchange(Exchange exchange, String target) throws Exception {
log.trace("Processing file: {} for exchange: {}", target, exchange);
try {
preWriteCheck();
// should we write to a temporary name and then afterwards rename to real target
boolean writeAsTempAndRename = ObjectHelper.isNotEmpty(endpoint.getTempFileName());
String tempTarget = null;
// remember if target exists to avoid checking twice
Boolean targetExists = null;
if (writeAsTempAndRename) {
// compute temporary name with the temp prefix
tempTarget = createTempFileName(exchange, target);
log.trace("Writing using tempNameFile: {}", tempTarget);
//if we should eager delete target file before deploying temporary file
if (endpoint.getFileExist() != GenericFileExist.TryRename && endpoint.isEagerDeleteTargetFile()) {
// cater for file exists option on the real target as
// the file operations code will work on the temp file
// if an existing file already exists what should we do?
targetExists = operations.existsFile(target);
if (targetExists) {
log.trace("EagerDeleteTargetFile, target exists");
if (endpoint.getFileExist() == GenericFileExist.Ignore) {
// ignore but indicate that the file was written
log.trace("An existing file already exists: {}. Ignore and do not override it.", target);
return;
} else if (endpoint.getFileExist() == GenericFileExist.Fail) {
throw new GenericFileOperationFailedException("File already exist: " + target + ". Cannot write new file.");
} else if (endpoint.isEagerDeleteTargetFile() && endpoint.getFileExist() == GenericFileExist.Override) {
// we override the target so we do this by deleting it so the temp file can be renamed later
// with success as the existing target file have been deleted
log.trace("Eagerly deleting existing file: {}", target);
if (!operations.deleteFile(target)) {
throw new GenericFileOperationFailedException("Cannot delete file: " + target);
}
}
}
}
// delete any pre existing temp file
if (operations.existsFile(tempTarget)) {
log.trace("Deleting existing temp file: {}", tempTarget);
if (!operations.deleteFile(tempTarget)) {
throw new GenericFileOperationFailedException("Cannot delete file: " + tempTarget);
}
}
}
// write/upload the file
writeFile(exchange, tempTarget != null ? tempTarget : target);
// if we did write to a temporary name then rename it to the real
// name after we have written the file
if (tempTarget != null) {
// if we did not eager delete the target file
if (endpoint.getFileExist() != GenericFileExist.TryRename && !endpoint.isEagerDeleteTargetFile()) {
// if an existing file already exists what should we do?
targetExists = operations.existsFile(target);
if (targetExists) {
log.trace("Not using EagerDeleteTargetFile, target exists");
if (endpoint.getFileExist() == GenericFileExist.Ignore) {
// ignore but indicate that the file was written
log.trace("An existing file already exists: {}. Ignore and do not override it.", target);
return;
} else if (endpoint.getFileExist() == GenericFileExist.Fail) {
throw new GenericFileOperationFailedException("File already exist: " + target + ". Cannot write new file.");
} else if (endpoint.getFileExist() == GenericFileExist.Override) {
// we override the target so we do this by deleting it so the temp file can be renamed later
// with success as the existing target file have been deleted
log.trace("Deleting existing file: {}", target);
if (!operations.deleteFile(target)) {
throw new GenericFileOperationFailedException("Cannot delete file: " + target);
}
}
}
}
// now we are ready to rename the temp file to the target file
log.trace("Renaming file: [{}] to: [{}]", tempTarget, target);
boolean renamed = operations.renameFile(tempTarget, target);
if (!renamed) {
throw new GenericFileOperationFailedException("Cannot rename file from: " + tempTarget + " to: " + target);
}
}
// any done file to write?
if (endpoint.getDoneFileName() != null) {
String doneFileName = endpoint.createDoneFileName(target);
ObjectHelper.notEmpty(doneFileName, "doneFileName", endpoint);
// create empty exchange with empty body to write as the done file
Exchange empty = new DefaultExchange(exchange);
empty.getIn().setBody("");
log.trace("Writing done file: [{}]", doneFileName);
// delete any existing done file
if (operations.existsFile(doneFileName)) {
if (!operations.deleteFile(doneFileName)) {
throw new GenericFileOperationFailedException("Cannot delete existing done file: " + doneFileName);
}
}
writeFile(empty, doneFileName);
}
// let's store the name we really used in the header, so end-users
// can retrieve it
exchange.getIn().setHeader(Exchange.FILE_NAME_PRODUCED, target);
} catch (Exception e) {
handleFailedWrite(exchange, e);
}
postWriteCheck();
}
/**
* If we fail writing out a file, we will call this method. This hook is
* provided to disconnect from servers or clean up files we created (if needed).
*/
public void handleFailedWrite(Exchange exchange, Exception exception) throws Exception {
throw exception;
}
/**
* Perform any actions that need to occur before we write such as connecting to an FTP server etc.
*/
public void preWriteCheck() throws Exception {
// nothing needed to check
}
/**
* Perform any actions that need to occur after we are done such as disconnecting.
*/
public void postWriteCheck() {
// nothing needed to check
}
public void writeFile(Exchange exchange, String fileName) throws GenericFileOperationFailedException {
// build directory if auto create is enabled
if (endpoint.isAutoCreate()) {
// we must normalize it (to avoid having both \ and / in the name which confuses java.io.File)
String name = FileUtil.normalizePath(fileName);
// use java.io.File to compute the file path
File file = new File(name);
String directory = file.getParent();
boolean absolute = FileUtil.isAbsolute(file);
if (directory != null) {
if (!operations.buildDirectory(directory, absolute)) {
log.debug("Cannot build directory [{}] (could be because of denied permissions)", directory);
}
}
}
// upload
if (log.isTraceEnabled()) {
log.trace("About to write [{}] to [{}] from exchange [{}]", new Object[]{fileName, getEndpoint(), exchange});
}
boolean success = operations.storeFile(fileName, exchange);
if (!success) {
throw new GenericFileOperationFailedException("Error writing file [" + fileName + "]");
}
log.debug("Wrote [{}] to [{}]", fileName, getEndpoint());
}
public String createFileName(Exchange exchange) {
String answer;
// overrule takes precedence
Object value;
Object overrule = exchange.getIn().getHeader(Exchange.OVERRULE_FILE_NAME);
if (overrule != null) {
if (overrule instanceof Expression) {
value = overrule;
} else {
value = exchange.getContext().getTypeConverter().convertTo(String.class, exchange, overrule);
}
} else {
value = exchange.getIn().getHeader(Exchange.FILE_NAME);
}
// if we have an overrule then override the existing header to use the overrule computed name from this point forward
if (overrule != null) {
exchange.getIn().setHeader(Exchange.FILE_NAME, value);
}
if (value != null && value instanceof String && StringHelper.hasStartToken((String) value, "simple")) {
log.warn("Simple expression: {} detected in header: {} of type String. This feature has been removed (see CAMEL-6748).", value, Exchange.FILE_NAME);
}
// expression support
Expression expression = endpoint.getFileName();
if (value != null && value instanceof Expression) {
expression = (Expression) value;
}
// evaluate the name as a String from the value
String name;
if (expression != null) {
log.trace("Filename evaluated as expression: {}", expression);
name = expression.evaluate(exchange, String.class);
} else {
name = exchange.getContext().getTypeConverter().convertTo(String.class, exchange, value);
}
// flatten name
if (name != null && endpoint.isFlatten()) {
// check for both windows and unix separators
int pos = Math.max(name.lastIndexOf("/"), name.lastIndexOf("\\"));
if (pos != -1) {
name = name.substring(pos + 1);
}
}
// compute path by adding endpoint starting directory
String endpointPath = endpoint.getConfiguration().getDirectory();
String baseDir = "";
if (endpointPath.length() > 0) {
// Its a directory so we should use it as a base path for the filename
// If the path isn't empty, we need to add a trailing / if it isn't already there
baseDir = endpointPath;
boolean trailingSlash = endpointPath.endsWith("/") || endpointPath.endsWith("\\");
if (!trailingSlash) {
baseDir += getFileSeparator();
}
}
if (name != null) {
answer = baseDir + name;
} else {
// use a generated filename if no name provided
answer = baseDir + endpoint.getGeneratedFileName(exchange.getIn());
}
if (endpoint.getConfiguration().needToNormalize()) {
// must normalize path to cater for Windows and other OS
answer = normalizePath(answer);
}
return answer;
}
public String createTempFileName(Exchange exchange, String fileName) {
String answer = fileName;
String tempName;
if (exchange.getIn().getHeader(Exchange.FILE_NAME) == null) {
// its a generated filename then add it to header so we can evaluate the expression
exchange.getIn().setHeader(Exchange.FILE_NAME, FileUtil.stripPath(fileName));
tempName = endpoint.getTempFileName().evaluate(exchange, String.class);
// and remove it again after evaluation
exchange.getIn().removeHeader(Exchange.FILE_NAME);
} else {
tempName = endpoint.getTempFileName().evaluate(exchange, String.class);
}
// check for both windows and unix separators
int pos = Math.max(answer.lastIndexOf("/"), answer.lastIndexOf("\\"));
if (pos == -1) {
// no path so use temp name as calculated
answer = tempName;
} else {
// path should be prefixed before the temp name
StringBuilder sb = new StringBuilder(answer.substring(0, pos + 1));
sb.append(tempName);
answer = sb.toString();
}
if (endpoint.getConfiguration().needToNormalize()) {
// must normalize path to cater for Windows and other OS
answer = normalizePath(answer);
}
return answer;
}
@Override
protected void doStart() throws Exception {
super.doStart();
ServiceHelper.startService(locks);
}
@Override
protected void doStop() throws Exception {
ServiceHelper.stopService(locks);
super.doStop();
}
}