com.google.apphosting.utils.config.AppEngineWebXmlReader Maven / Gradle / Ivy
/*
* Copyright 2021 Google LLC
*
* Licensed 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
*
* https://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.google.apphosting.utils.config;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Creates an {@link AppEngineWebXml} instance from
* WEB-INF/appengine-web.xml. If you want to read the configuration
* from something that isn't a file, subclass and override
* {@link #getInputStream()}.
*
*/
public class AppEngineWebXmlReader {
private static final Logger logger =
Logger.getLogger(AppEngineWebXmlReader.class.getName());
private static final String CONCURRENT_REQUESTS_URL =
"http://code.google.com/appengine/docs/java/config/appconfig.html#Using_Concurrent_Requests";
private static final String DATASTORE_AUTO_IDS_URL =
"http://developers.google.com/appengine/docs/java/datastore/entities#Kinds_and_Identifiers";
private static final String APPCFG_AUTO_IDS_URL =
"http://developers.google.com/appengine/docs/java/config/appconfig#auto_id_policy";
public static final String DEFAULT_RELATIVE_FILENAME = "WEB-INF/appengine-web.xml";
// Absolute location of the config file
private final String filename;
/**
* Creates a reader for appengine-web.xml.
*
* @param appDir The directory in which the config file resides.
* @param relativeFilename The path to the config file, relative to
* {@code appDir}.
*/
public AppEngineWebXmlReader(String appDir, String relativeFilename) {
// Be friendly, make sure we end with a slash.
if (appDir.length() > 0 && appDir.charAt(appDir.length() - 1) != File.separatorChar) {
appDir += File.separatorChar;
}
this.filename = appDir + relativeFilename;
}
/**
* Creates a reader for appengine-web.xml.
*
* @param appDir The directory in which the config file resides. The
* path to the config file relative to the directory is assumed to be
* {@link #DEFAULT_RELATIVE_FILENAME}.
*/
public AppEngineWebXmlReader(String appDir) {
this(appDir, DEFAULT_RELATIVE_FILENAME);
}
/**
* @return A {@link AppEngineWebXml} config object derived from the
* contents of WEB-INF/appengine-web.xml.
*
* @throws AppEngineConfigException If WEB-INF/appengine-web.xml does
* not exist. Also thrown if we are unable to parse the xml.
*/
public AppEngineWebXml readAppEngineWebXml() {
InputStream is = null;
AppEngineWebXml appEngineWebXml;
try {
is = getInputStream();
appEngineWebXml = processXml(is);
logger.fine("Successfully processed " + getFilename());
if (!appEngineWebXml.getThreadsafeValueProvided() && !appEngineWebXml.isJava11OrAbove()) {
if (allowMissingThreadsafeElement()) {
// make some noise if there is no element.
logger.warning("appengine-web.xml does not contain a element. This will "
+ "be treated as an error the next time you deploy.\nSee " + CONCURRENT_REQUESTS_URL
+ " for more information.\nYou probably want to enable concurrent requests.");
} else {
throw new AppEngineConfigException("appengine-web.xml does not contain a "
+ "element.\nSee " + CONCURRENT_REQUESTS_URL + " for more information.\nYou probably "
+ "want to enable concurrent requests.");
}
}
if ("legacy".equals(appEngineWebXml.getAutoIdPolicy())) {
logger.warning("You have set the datastore auto id policy to 'legacy'. It is recommended "
+ "that you select 'default' instead.\nLegacy auto ids are deprecated. You can "
+ "continue to allocate legacy ids manually using the allocateIds() API functions.\n"
+ "For more information see:\n"
+ APPCFG_AUTO_IDS_URL + "\n" + DATASTORE_AUTO_IDS_URL + "\n");
}
} catch (Exception e) {
String msg = "Received exception processing " + getFilename();
logger.log(Level.SEVERE, msg, e);
// Guarantee that the only exceptions thrown from this method are of
// type AppEngineConfigException.
if (e instanceof AppEngineConfigException) {
throw (AppEngineConfigException) e;
}
throw new AppEngineConfigException(msg, e);
} finally {
close(is);
}
return appEngineWebXml;
}
protected boolean allowMissingThreadsafeElement() {
return false;
}
public String getFilename() {
return filename;
}
private void close(InputStream is) {
if (is != null) {
try {
is.close();
} catch (IOException e) {
throw new AppEngineConfigException(e);
}
}
}
// broken out for testing
protected AppEngineWebXml processXml(InputStream is) {
return new AppEngineWebXmlProcessor().processXml(is);
}
protected InputStream getInputStream() {
try {
return new FileInputStream(getFilename());
} catch (FileNotFoundException fnfe) {
// Having the full path in the exception is helpful for debugging.
throw new AppEngineConfigException(
"Could not locate " + new File(getFilename()).getAbsolutePath(), fnfe);
}
}
}