/**
* Copyright (C) 2011-2012 Typesafe Inc. <http://typesafe.com>
*/
package com.crashnote.core.config.helper.impl;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FilterReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.StringReader;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URI;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Properties;
import com.crashnote.core.config.helper.ConfigException;
import com.crashnote.core.config.helper.ConfigIncludeContext;
import com.crashnote.core.config.helper.ConfigObject;
import com.crashnote.core.config.helper.ConfigOrigin;
import com.crashnote.core.config.helper.ConfigParseOptions;
import com.crashnote.core.config.helper.ConfigParseable;
import com.crashnote.core.config.helper.ConfigSyntax;
import com.crashnote.core.config.helper.ConfigValue;
/**
* This is public but it's only for use by the config package; DO NOT TOUCH. The
* point of this class is to avoid "propagating" each overload on
* "thing which can be parsed" through multiple interfaces. Most interfaces can
* have just one overload that takes a Parseable. Also it's used as an abstract
* "resource handle" in the ConfigIncluder interface.
*/
public abstract class Parseable implements ConfigParseable {
private ConfigIncludeContext includeContext;
private ConfigParseOptions initialOptions;
private ConfigOrigin initialOrigin;
private static final ThreadLocal<LinkedList<Parseable>> parseStack = new ThreadLocal<LinkedList<Parseable>>() {
@Override
protected LinkedList<Parseable> initialValue() {
return new LinkedList<Parseable>();
}
};
private static final int MAX_INCLUDE_DEPTH = 50;
protected Parseable() {
}
private ConfigParseOptions fixupOptions(final ConfigParseOptions baseOptions) {
ConfigSyntax syntax = baseOptions.getSyntax();
if (syntax == null) {
syntax = guessSyntax();
}
if (syntax == null) {
syntax = ConfigSyntax.CONF;
}
ConfigParseOptions modified = baseOptions.setSyntax(syntax);
// make sure the app-provided includer falls back to default
modified = modified.appendIncluder(ConfigImpl.defaultIncluder());
// make sure the app-provided includer is complete
modified = modified.setIncluder(SimpleIncluder.makeFull(modified.getIncluder()));
return modified;
}
protected void postConstruct(final ConfigParseOptions baseOptions) {
this.initialOptions = fixupOptions(baseOptions);
this.includeContext = new SimpleIncludeContext(this);
if (initialOptions.getOriginDescription() != null)
initialOrigin = SimpleConfigOrigin.newSimple(initialOptions.getOriginDescription());
else
initialOrigin = createOrigin();
}
// the general idea is that any work should be in here, not in the
// constructor, so that exceptions are thrown from the public parse()
// function and not from the creation of the Parseable.
// Essentially this is a lazy field. The parser should close the
// reader when it's done with it.
// ALSO, IMPORTANT: if the file or URL is not found, this must throw.
// to support the "allow missing" feature.
protected abstract Reader reader() throws IOException;
protected static void trace(final String message) {
if (ConfigImpl.traceLoadsEnabled()) {
ConfigImpl.trace(message);
}
}
ConfigSyntax guessSyntax() {
return null;
}
ConfigParseable relativeTo(final String filename) {
// fall back to classpath; we treat the "filename" as absolute
// (don't add a package name in front),
// if it starts with "/" then remove the "/", for consistency
// with ParseableResources.relativeTo
String resource = filename;
if (filename.startsWith("/"))
resource = filename.substring(1);
return newResources(resource, options().setOriginDescription(null));
}
ConfigIncludeContext includeContext() {
return includeContext;
}
static AbstractConfigObject forceParsedToObject(final ConfigValue value) {
if (value instanceof AbstractConfigObject) {
return (AbstractConfigObject) value;
} else {
throw new ConfigException.WrongType(value.origin(), "", "object at file root", value
.valueType().name());
}
}
@Override
public ConfigObject parse(final ConfigParseOptions baseOptions) {
final LinkedList<Parseable> stack = parseStack.get();
if (stack.size() >= MAX_INCLUDE_DEPTH) {
throw new ConfigException.Parse(initialOrigin, "include statements nested more than "
+ MAX_INCLUDE_DEPTH
+ " times, you probably have a cycle in your includes. Trace: " + stack);
}
stack.addFirst(this);
try {
return forceParsedToObject(parseValue(baseOptions));
} finally {
stack.removeFirst();
if (stack.isEmpty()) {
parseStack.remove();
}
}
}
final AbstractConfigValue parseValue(final ConfigParseOptions baseOptions) {
// note that we are NOT using our "initialOptions",
// but using the ones from the passed-in options. The idea is that
// callers can get our original options and then parse with different
// ones if they want.
final ConfigParseOptions options = fixupOptions(baseOptions);
// passed-in options can override origin
final ConfigOrigin origin;
if (options.getOriginDescription() != null)
origin = SimpleConfigOrigin.newSimple(options.getOriginDescription());
else
origin = initialOrigin;
return parseValue(origin, options);
}
final private AbstractConfigValue parseValue(final ConfigOrigin origin,
final ConfigParseOptions finalOptions) {
try {
return rawParseValue(origin, finalOptions);
} catch (IOException e) {
if (finalOptions.getAllowMissing()) {
return SimpleConfigObject.emptyMissing(origin);
} else {
throw new ConfigException.IO(origin, e.getMessage(), e);
}
}
}
// this is parseValue without post-processing the IOException or handling
// options.getAllowMissing()
protected AbstractConfigValue rawParseValue(final ConfigOrigin origin, final ConfigParseOptions finalOptions)
throws IOException {
final Reader reader = reader();
try {
return rawParseValue(reader, origin, finalOptions);
} finally {
reader.close();
}
}
protected AbstractConfigValue rawParseValue(final Reader reader, final ConfigOrigin origin,
final ConfigParseOptions finalOptions) throws IOException {
if (finalOptions.getSyntax() == ConfigSyntax.PROPERTIES) {
return PropertiesParser.parse(reader, origin);
} else {
final Iterator<Token> tokens = Tokenizer.tokenize(origin, reader, finalOptions.getSyntax());
return Parser.parse(tokens, origin, finalOptions, includeContext());
}
}
public ConfigObject parse() {
return forceParsedToObject(parseValue(options()));
}
AbstractConfigValue parseValue() {
return parseValue(options());
}
@Override
public final ConfigOrigin origin() {
return initialOrigin;
}
protected abstract ConfigOrigin createOrigin();
@Override
public ConfigParseOptions options() {
return initialOptions;
}
@Override
public String toString() {
return getClass().getSimpleName();
}
private static ConfigSyntax syntaxFromExtension(final String name) {
if (name.endsWith(".json"))
return ConfigSyntax.JSON;
else if (name.endsWith(".conf"))
return ConfigSyntax.CONF;
else if (name.endsWith(".properties"))
return ConfigSyntax.PROPERTIES;
else
return null;
}
private static Reader readerFromStream(final InputStream input) {
try {
// well, this is messed up. If we aren't going to close
// the passed-in InputStream then we have no way to
// close these readers. So maybe we should not have an
// InputStream version, only a Reader version.
final Reader reader = new InputStreamReader(input, "UTF-8");
return new BufferedReader(reader);
} catch (UnsupportedEncodingException e) {
throw new ConfigException.BugOrBroken("Java runtime does not support UTF-8", e);
}
}
private static Reader doNotClose(final Reader input) {
return new FilterReader(input) {
@Override
public void close() {
// NOTHING.
}
};
}
static URL relativeTo(final URL url, final String filename) {
// I'm guessing this completely fails on Windows, help wanted
if (new File(filename).isAbsolute())
return null;
try {
final URI siblingURI = url.toURI();
final URI relative = new URI(filename);
// this seems wrong, but it's documented that the last
// element of the path in siblingURI gets stripped out,
// so to get something in the same directory as
// siblingURI we just call resolve().
final URL resolved = siblingURI.resolve(relative).toURL();
return resolved;
} catch (MalformedURLException e) {
return null;
} catch (URISyntaxException e) {
return null;
} catch (IllegalArgumentException e) {
return null;
}
}
static File relativeTo(final File file, final String filename) {
final File child = new File(filename);
if (child.isAbsolute())
return null;
final File parent = file.getParentFile();
if (parent == null)
return null;
else
return new File(parent, filename);
}
// this is a parseable that doesn't exist and just throws when you try to
// parse it
private final static class ParseableNotFound extends Parseable {
final private String what;
final private String message;
ParseableNotFound(final String what, final String message, final ConfigParseOptions options) {
this.what = what;
this.message = message;
postConstruct(options);
}
@Override
protected Reader reader() throws IOException {
throw new FileNotFoundException(message);
}
@Override
protected ConfigOrigin createOrigin() {
return SimpleConfigOrigin.newSimple(what);
}
}
public static Parseable newNotFound(final String whatNotFound, final String message,
final ConfigParseOptions options) {
return new ParseableNotFound(whatNotFound, message, options);
}
private final static class ParseableReader extends Parseable {
final private Reader reader;
ParseableReader(final Reader reader, final ConfigParseOptions options) {
this.reader = reader;
postConstruct(options);
}
@Override
protected Reader reader() {
if (ConfigImpl.traceLoadsEnabled())
trace("Loading config from reader " + reader);
return reader;
}
@Override
protected ConfigOrigin createOrigin() {
return SimpleConfigOrigin.newSimple("Reader");
}
}
/**
* note that we will never close this reader; you have to do it when parsing
* is complete.
*/
public static Parseable newReader(final Reader reader, final ConfigParseOptions options) {
return new ParseableReader(doNotClose(reader), options);
}
private final static class ParseableString extends Parseable {
final private String input;
ParseableString(final String input, final ConfigParseOptions options) {
this.input = input;
postConstruct(options);
}
@Override
protected Reader reader() {
if (ConfigImpl.traceLoadsEnabled())
trace("Loading config from a String " + input);
return new StringReader(input);
}
@Override
protected ConfigOrigin createOrigin() {
return SimpleConfigOrigin.newSimple("String");
}
@Override
public String toString() {
return getClass().getSimpleName() + "(" + input + ")";
}
}
public static Parseable newString(final String input, final ConfigParseOptions options) {
return new ParseableString(input, options);
}
private final static class ParseableURL extends Parseable {
final private URL input;
ParseableURL(final URL input, final ConfigParseOptions options) {
this.input = input;
postConstruct(options);
}
@Override
protected Reader reader() throws IOException {
if (ConfigImpl.traceLoadsEnabled())
trace("Loading config from a URL: " + input.toExternalForm());
final InputStream stream = input.openStream();
return readerFromStream(stream);
}
@Override
ConfigSyntax guessSyntax() {
return syntaxFromExtension(input.getPath());
}
@Override
ConfigParseable relativeTo(final String filename) {
final URL url = relativeTo(input, filename);
if (url == null)
return null;
return newURL(url, options().setOriginDescription(null));
}
@Override
protected ConfigOrigin createOrigin() {
return SimpleConfigOrigin.newURL(input);
}
@Override
public String toString() {
return getClass().getSimpleName() + "(" + input.toExternalForm() + ")";
}
}
public static Parseable newURL(final URL input, final ConfigParseOptions options) {
// we want file: URLs and files to always behave the same, so switch
// to a file if it's a file: URL
if (input.getProtocol().equals("file")) {
return newFile(ConfigImplUtil.urlToFile(input), options);
} else {
return new ParseableURL(input, options);
}
}
private final static class ParseableFile extends Parseable {
final private File input;
ParseableFile(final File input, final ConfigParseOptions options) {
this.input = input;
postConstruct(options);
}
@Override
protected Reader reader() throws IOException {
if (ConfigImpl.traceLoadsEnabled())
trace("Loading config from a file: " + input);
final InputStream stream = new FileInputStream(input);
return readerFromStream(stream);
}
@Override
ConfigSyntax guessSyntax() {
return syntaxFromExtension(input.getName());
}
@Override
ConfigParseable relativeTo(final String filename) {
final File sibling;
if ((new File(filename)).isAbsolute()) {
sibling = new File(filename);
} else {
// this may return null
sibling = relativeTo(input, filename);
}
if (sibling == null)
return null;
if (sibling.exists()) {
return newFile(sibling, options().setOriginDescription(null));
} else {
return super.relativeTo(filename);
}
}
@Override
protected ConfigOrigin createOrigin() {
return SimpleConfigOrigin.newFile(input.getPath());
}
@Override
public String toString() {
return getClass().getSimpleName() + "(" + input.getPath() + ")";
}
}
public static Parseable newFile(final File input, final ConfigParseOptions options) {
return new ParseableFile(input, options);
}
private final static class ParseableResources extends Parseable {
final private String resource;
ParseableResources(final String resource, final ConfigParseOptions options) {
this.resource = resource;
postConstruct(options);
}
@Override
protected Reader reader() throws IOException {
throw new ConfigException.BugOrBroken("reader() should not be called on resources");
}
@Override
protected AbstractConfigObject rawParseValue(final ConfigOrigin origin,
final ConfigParseOptions finalOptions) throws IOException {
final ClassLoader loader = finalOptions.getClassLoader();
final Enumeration<URL> e = loader.getResources(resource);
if (!e.hasMoreElements()) {
if (ConfigImpl.traceLoadsEnabled())
trace("Loading config from class loader " + loader
+ " but there were no resources called " + resource);
throw new IOException("resource not found on classpath: " + resource);
}
AbstractConfigObject merged = SimpleConfigObject.empty(origin);
while (e.hasMoreElements()) {
final URL url = e.nextElement();
if (ConfigImpl.traceLoadsEnabled())
trace("Loading config from URL " + url.toExternalForm() + " from class loader "
+ loader);
final ConfigOrigin elementOrigin = ((SimpleConfigOrigin) origin).addURL(url);
AbstractConfigValue v;
// it's tempting to use ParseableURL here but it would be wrong
// because the wrong relativeTo() would be used for includes.
InputStream stream = url.openStream();
try {
final Reader reader = readerFromStream(stream);
stream = null; // reader now owns it
try {
// parse in "raw" mode which will throw any IOException
// from here.
v = rawParseValue(reader, elementOrigin, finalOptions);
} finally {
reader.close();
}
} finally {
// stream is null if the reader owns it
if (stream != null)
stream.close();
}
merged = merged.withFallback(v);
}
return merged;
}
@Override
ConfigSyntax guessSyntax() {
return syntaxFromExtension(resource);
}
static String parent(final String resource) {
// the "resource" is not supposed to begin with a "/"
// because it's supposed to be the raw resource
// (ClassLoader#getResource), not the
// resource "syntax" (Class#getResource)
final int i = resource.lastIndexOf('/');
if (i < 0) {
return null;
} else {
return resource.substring(0, i);
}
}
@Override
ConfigParseable relativeTo(final String sibling) {
if (sibling.startsWith("/")) {
// if it starts with "/" then don't make it relative to
// the including resource
return newResources(sibling.substring(1), options().setOriginDescription(null));
} else {
// here we want to build a new resource name and let
// the class loader have it, rather than getting the
// url with getResource() and relativizing to that url.
// This is needed in case the class loader is going to
// search a classpath.
final String parent = parent(resource);
if (parent == null)
return newResources(sibling, options().setOriginDescription(null));
else
return newResources(parent + "/" + sibling, options()
.setOriginDescription(null));
}
}
@Override
protected ConfigOrigin createOrigin() {
return SimpleConfigOrigin.newResource(resource);
}
@Override
public String toString() {
return getClass().getSimpleName() + "(" + resource + ")";
}
}
public static Parseable newResources(final Class<?> klass, final String resource, final ConfigParseOptions options) {
return newResources(convertResourceName(klass, resource),
options.setClassLoader(klass.getClassLoader()));
}
// this function is supposed to emulate the difference
// between Class.getResource and ClassLoader.getResource
// (unfortunately there doesn't seem to be public API for it).
// We're using it because the Class API is more limited,
// for example it lacks getResources(). So we want to be able to
// use ClassLoader directly.
private static String convertResourceName(final Class<?> klass, final String resource) {
if (resource.startsWith("/")) {
// "absolute" resource, chop the slash
return resource.substring(1);
} else {
final String className = klass.getName();
final int i = className.lastIndexOf('.');
if (i < 0) {
// no package
return resource;
} else {
// need to be relative to the package
final String packageName = className.substring(0, i);
final String packagePath = packageName.replace('.', '/');
return packagePath + "/" + resource;
}
}
}
public static Parseable newResources(final String resource, final ConfigParseOptions options) {
return new ParseableResources(resource, options);
}
private final static class ParseableProperties extends Parseable {
final private Properties props;
ParseableProperties(final Properties props, final ConfigParseOptions options) {
this.props = props;
postConstruct(options);
}
@Override
protected Reader reader() throws IOException {
throw new ConfigException.BugOrBroken("reader() should not be called on props");
}
@Override
protected AbstractConfigObject rawParseValue(final ConfigOrigin origin,
final ConfigParseOptions finalOptions) {
if (ConfigImpl.traceLoadsEnabled())
trace("Loading config from properties " + props);
return PropertiesParser.fromProperties(origin, props);
}
@Override
ConfigSyntax guessSyntax() {
return ConfigSyntax.PROPERTIES;
}
@Override
protected ConfigOrigin createOrigin() {
return SimpleConfigOrigin.newSimple("properties");
}
@Override
public String toString() {
return getClass().getSimpleName() + "(" + props.size() + " props)";
}
}
public static Parseable newProperties(final Properties properties, final ConfigParseOptions options) {
return new ParseableProperties(properties, options);
}
}