/**
* 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.hadoop.conf;
import java.io.BufferedInputStream;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.Reader;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.ListIterator;
import java.util.Map;
import java.util.Properties;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.WeakHashMap;
import java.util.concurrent.CopyOnWriteArrayList;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.io.WritableUtils;
import org.apache.hadoop.util.StringUtils;
import org.w3c.dom.DOMException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.Text;
import org.xml.sax.SAXException;
/**
* Provides access to configuration parameters.
*
* <h4 id="Resources">Resources</h4>
*
* <p>Configurations are specified by resources. A resource contains a set of
* name/value pairs as XML data. Each resource is named by either a
* <code>String</code> or by a {@link Path}. If named by a <code>String</code>,
* then the classpath is examined for a file with that name. If named by a
* <code>Path</code>, then the local filesystem is examined directly, without
* referring to the classpath.
*
* <p>Unless explicitly turned off, Hadoop by default specifies two
* resources, loaded in-order from the classpath: <ol>
* <li><tt><a href="{@docRoot}/../core-default.html">core-default.xml</a>
* </tt>: Read-only defaults for hadoop.</li>
* <li><tt>core-site.xml</tt>: Site-specific configuration for a given hadoop
* installation.</li>
* </ol>
* Applications may add additional resources, which are loaded
* subsequent to these resources in the order they are added.
*
* <h4 id="FinalParams">Final Parameters</h4>
*
* <p>Configuration parameters may be declared <i>final</i>.
* Once a resource declares a value final, no subsequently-loaded
* resource can alter that value.
* For example, one might define a final parameter with:
* <tt><pre>
* <property>
* <name>dfs.client.buffer.dir</name>
* <value>/tmp/hadoop/dfs/client</value>
* <b><final>true</final></b>
* </property></pre></tt>
*
* Administrators typically define parameters as final in
* <tt>core-site.xml</tt> for values that user applications may not alter.
*
* <h4 id="VariableExpansion">Variable Expansion</h4>
*
* <p>Value strings are first processed for <i>variable expansion</i>. The
* available properties are:<ol>
* <li>Other properties defined in this Configuration; and, if a name is
* undefined here,</li>
* <li>Properties in {@link System#getProperties()}.</li>
* </ol>
*
* <p>For example, if a configuration resource contains the following property
* definitions:
* <tt><pre>
* <property>
* <name>basedir</name>
* <value>/user/${<i>user.name</i>}</value>
* </property>
*
* <property>
* <name>tempdir</name>
* <value>${<i>basedir</i>}/tmp</value>
* </property></pre></tt>
*
* When <tt>conf.get("tempdir")</tt> is called, then <tt>${<i>basedir</i>}</tt>
* will be resolved to another property in this Configuration, while
* <tt>${<i>user.name</i>}</tt> would then ordinarily be resolved to the value
* of the System property with that name.
*/
public class Configuration implements Iterable<Map.Entry<String,String>>,
Writable {
private static final Log LOG =
LogFactory.getLog(Configuration.class);
private boolean quietmode = true;
/**
* List of configuration resources.
*/
private ArrayList<Object> resources = new ArrayList<Object>();
/**
* List of configuration parameters marked <b>final</b>.
*/
private Set<String> finalParameters = new HashSet<String>();
private boolean loadDefaults = true;
/**
* Configurtion objects
*/
private static final WeakHashMap<Configuration,Object> REGISTRY =
new WeakHashMap<Configuration,Object>();
/**
* List of default Resources. Resources are loaded in the order of the list
* entries
*/
private static final CopyOnWriteArrayList<String> defaultResources =
new CopyOnWriteArrayList<String>();
static{
//print deprecation warning if hadoop-site.xml is found in classpath
ClassLoader cL = Thread.currentThread().getContextClassLoader();
if (cL == null) {
cL = Configuration.class.getClassLoader();
}
if(cL.getResource("hadoop-site.xml")!=null) {
LOG.warn("DEPRECATED: hadoop-site.xml found in the classpath. " +
"Usage of hadoop-site.xml is deprecated. Instead use core-site.xml, "
+ "mapred-site.xml and hdfs-site.xml to override properties of " +
"core-default.xml, mapred-default.xml and hdfs-default.xml " +
"respectively");
}
addDefaultResource("core-default.xml");
addDefaultResource("core-site.xml");
}
private Properties properties;
private Properties overlay;
private ClassLoader classLoader;
{
classLoader = Thread.currentThread().getContextClassLoader();
if (classLoader == null) {
classLoader = Configuration.class.getClassLoader();
}
}
/** A new configuration. */
public Configuration() {
this(true);
}
/** A new configuration where the behavior of reading from the default
* resources can be turned off.
*
* If the parameter {@code loadDefaults} is false, the new instance
* will not load resources from the default files.
* @param loadDefaults specifies whether to load from the default files
*/
public Configuration(boolean loadDefaults) {
this.loadDefaults = loadDefaults;
if (LOG.isDebugEnabled()) {
LOG.debug(StringUtils.stringifyException(new IOException("config()")));
}
synchronized(Configuration.class) {
REGISTRY.put(this, null);
}
}
/**
* A new configuration with the same settings cloned from another.
*
* @param other the configuration from which to clone settings.
*/
@SuppressWarnings("unchecked")
public Configuration(Configuration other) {
if (LOG.isDebugEnabled()) {
LOG.debug(StringUtils.stringifyException
(new IOException("config(config)")));
}
this.resources = (ArrayList)other.resources.clone();
synchronized(other) {
if (other.properties != null) {
this.properties = (Properties)other.properties.clone();
}
if (other.overlay!=null) {
this.overlay = (Properties)other.overlay.clone();
}
}
this.finalParameters = new HashSet<String>(other.finalParameters);
synchronized(Configuration.class) {
REGISTRY.put(this, null);
}
}
/**
* Add a default resource. Resources are loaded in the order of the resources
* added.
* @param name file name. File should be present in the classpath.
*/
public static synchronized void addDefaultResource(String name) {
if(!defaultResources.contains(name)) {
defaultResources.add(name);
for(Configuration conf : REGISTRY.keySet()) {
if(conf.loadDefaults) {
conf.reloadConfiguration();
}
}
}
}
/**
* Add a configuration resource.
*
* The properties of this resource will override properties of previously
* added resources, unless they were marked <a href="#Final">final</a>.
*
* @param name resource to be added, the classpath is examined for a file
* with that name.
*/
public void addResource(String name) {
addResourceObject(name);
}
/**
* Add a configuration resource.
*
* The properties of this resource will override properties of previously
* added resources, unless they were marked <a href="#Final">final</a>.
*
* @param url url of the resource to be added, the local filesystem is
* examined directly to find the resource, without referring to
* the classpath.
*/
public void addResource(URL url) {
addResourceObject(url);
}
/**
* Add a configuration resource.
*
* The properties of this resource will override properties of previously
* added resources, unless they were marked <a href="#Final">final</a>.
*
* @param file file-path of resource to be added, the local filesystem is
* examined directly to find the resource, without referring to
* the classpath.
*/
public void addResource(Path file) {
addResourceObject(file);
}
/**
* Add a configuration resource.
*
* The properties of this resource will override properties of previously
* added resources, unless they were marked <a href="#Final">final</a>.
*
* @param in InputStream to deserialize the object from.
*/
public void addResource(InputStream in) {
addResourceObject(in);
}
/**
* Reload configuration from previously added resources.
*
* This method will clear all the configuration read from the added
* resources, and final parameters. This will make the resources to
* be read again before accessing the values. Values that are added
* via set methods will overlay values read from the resources.
*/
public synchronized void reloadConfiguration() {
properties = null; // trigger reload
finalParameters.clear(); // clear site-limits
}
private synchronized void addResourceObject(Object resource) {
resources.add(resource); // add to resources
reloadConfiguration();
}
private static Pattern varPat = Pattern.compile("\\$\\{[^\\}\\$\u0020]+\\}");
private static int MAX_SUBST = 20;
private String substituteVars(String expr) {
if (expr == null) {
return null;
}
Matcher match = varPat.matcher("");
String eval = expr;
for(int s=0; s<MAX_SUBST; s++) {
match.reset(eval);
if (!match.find()) {
return eval;
}
String var = match.group();
var = var.substring(2, var.length()-1); // remove ${ .. }
String val = null;
try {
val = System.getProperty(var);
} catch(SecurityException se) {
LOG.warn("Unexpected SecurityException in Configuration", se);
}
if (val == null) {
val = getRaw(var);
}
if (val == null) {
return eval; // return literal ${var}: var is unbound
}
// substitute
eval = eval.substring(0, match.start())+val+eval.substring(match.end());
}
throw new IllegalStateException("Variable substitution depth too large: "
+ MAX_SUBST + " " + expr);
}
/**
* Get the value of the <code>name</code> property, <code>null</code> if
* no such property exists.
*
* Values are processed for <a href="#VariableExpansion">variable expansion</a>
* before being returned.
*
* @param name the property name.
* @return the value of the <code>name</code> property,
* or null if no such property exists.
*/
public String get(String name) {
return substituteVars(getProps().getProperty(name));
}
/**
* Get the value of the <code>name</code> property, without doing
* <a href="#VariableExpansion">variable expansion</a>.
*
* @param name the property name.
* @return the value of the <code>name</code> property,
* or null if no such property exists.
*/
public String getRaw(String name) {
return getProps().getProperty(name);
}
/**
* Set the <code>value</code> of the <code>name</code> property.
*
* @param name property name.
* @param value property value.
*/
public void set(String name, String value) {
getOverlay().setProperty(name, value);
getProps().setProperty(name, value);
}
/**
* Sets a property if it is currently unset.
* @param name the property name
* @param value the new value
*/
public void setIfUnset(String name, String value) {
if (get(name) == null) {
set(name, value);
}
}
private synchronized Properties getOverlay() {
if (overlay==null){
overlay=new Properties();
}
return overlay;
}
/**
* Get the value of the <code>name</code> property. If no such property
* exists, then <code>defaultValue</code> is returned.
*
* @param name property name.
* @param defaultValue default value.
* @return property value, or <code>defaultValue</code> if the property
* doesn't exist.
*/
public String get(String name, String defaultValue) {
return substituteVars(getProps().getProperty(name, defaultValue));
}
/**
* Get the value of the <code>name</code> property as an <code>int</code>.
*
* If no such property exists, or if the specified value is not a valid
* <code>int</code>, then <code>defaultValue</code> is returned.
*
* @param name property name.
* @param defaultValue default value.
* @return property value as an <code>int</code>,
* or <code>defaultValue</code>.
*/
public int getInt(String name, int defaultValue) {
String valueString = get(name);
if (valueString == null)
return defaultValue;
try {
String hexString = getHexDigits(valueString);
if (hexString != null) {
return Integer.parseInt(hexString, 16);
}
return Integer.parseInt(valueString);
} catch (NumberFormatException e) {
return defaultValue;
}
}
/**
* Set the value of the <code>name</code> property to an <code>int</code>.
*
* @param name property name.
* @param value <code>int</code> value of the property.
*/
public void setInt(String name, int value) {
set(name, Integer.toString(value));
}
/**
* Get the value of the <code>name</code> property as a <code>long</code>.
* If no such property is specified, or if the specified value is not a valid
* <code>long</code>, then <code>defaultValue</code> is returned.
*
* @param name property name.
* @param defaultValue default value.
* @return property value as a <code>long</code>,
* or <code>defaultValue</code>.
*/
public long getLong(String name, long defaultValue) {
String valueString = get(name);
if (valueString == null)
return defaultValue;
try {
String hexString = getHexDigits(valueString);
if (hexString != null) {
return Long.parseLong(hexString, 16);
}
return Long.parseLong(valueString);
} catch (NumberFormatException e) {
return defaultValue;
}
}
private String getHexDigits(String value) {
boolean negative = false;
String str = value;
String hexString = null;
if (value.startsWith("-")) {
negative = true;
str = value.substring(1);
}
if (str.startsWith("0x") || str.startsWith("0X")) {
hexString = str.substring(2);
if (negative) {
hexString = "-" + hexString;
}
return hexString;
}
return null;
}
/**
* Set the value of the <code>name</code> property to a <code>long</code>.
*
* @param name property name.
* @param value <code>long</code> value of the property.
*/
public void setLong(String name, long value) {
set(name, Long.toString(value));
}
/**
* Get the value of the <code>name</code> property as a <code>float</code>.
* If no such property is specified, or if the specified value is not a valid
* <code>float</code>, then <code>defaultValue</code> is returned.
*
* @param name property name.
* @param defaultValue default value.
* @return property value as a <code>float</code>,
* or <code>defaultValue</code>.
*/
public float getFloat(String name, float defaultValue) {
String valueString = get(name);
if (valueString == null)
return defaultValue;
try {
return Float.parseFloat(valueString);
} catch (NumberFormatException e) {
return defaultValue;
}
}
/**
* Set the value of the <code>name</code> property to a <code>float</code>.
*
* @param name property name.
* @param value property value.
*/
public void setFloat(String name, float value) {
set(name,Float.toString(value));
}
/**
* Get the value of the <code>name</code> property as a <code>boolean</code>.
* If no such property is specified, or if the specified value is not a valid
* <code>boolean</code>, then <code>defaultValue</code> is returned.
*
* @param name property name.
* @param defaultValue default value.
* @return property value as a <code>boolean</code>,
* or <code>defaultValue</code>.
*/
public boolean getBoolean(String name, boolean defaultValue) {
String valueString = get(name);
if ("true".equals(valueString))
return true;
else if ("false".equals(valueString))
return false;
else return defaultValue;
}
/**
* Set the value of the <code>name</code> property to a <code>boolean</code>.
*
* @param name property name.
* @param value <code>boolean</code> value of the property.
*/
public void setBoolean(String name, boolean value) {
set(name, Boolean.toString(value));
}
/**
* Set the given property, if it is currently unset.
* @param name property name
* @param value new value
*/
public void setBooleanIfUnset(String name, boolean value) {
setIfUnset(name, Boolean.toString(value));
}
/**
* A class that represents a set of positive integer ranges. It parses
* strings of the form: "2-3,5,7-" where ranges are separated by comma and
* the lower/upper bounds are separated by dash. Either the lower or upper
* bound may be omitted meaning all values up to or over. So the string
* above means 2, 3, 5, and 7, 8, 9, ...
*/
public static class IntegerRanges {
private static class Range {
int start;
int end;
}
List<Range> ranges = new ArrayList<Range>();
public IntegerRanges() {
}
public IntegerRanges(String newValue) {
StringTokenizer itr = new StringTokenizer(newValue, ",");
while (itr.hasMoreTokens()) {
String rng = itr.nextToken().trim();
String[] parts = rng.split("-", 3);
if (parts.length < 1 || parts.length > 2) {
throw new IllegalArgumentException("integer range badly formed: " +
rng);
}
Range r = new Range();
r.start = convertToInt(parts[0], 0);
if (parts.length == 2) {
r.end = convertToInt(parts[1], Integer.MAX_VALUE);
} else {
r.end = r.start;
}
if (r.start > r.end) {
throw new IllegalArgumentException("IntegerRange from " + r.start +
" to " + r.end + " is invalid");
}
ranges.add(r);
}
}
/**
* Convert a string to an int treating empty strings as the default value.
* @param value the string value
* @param defaultValue the value for if the string is empty
* @return the desired integer
*/
private static int convertToInt(String value, int defaultValue) {
String trim = value.trim();
if (trim.length() == 0) {
return defaultValue;
}
return Integer.parseInt(trim);
}
/**
* Is the given value in the set of ranges
* @param value the value to check
* @return is the value in the ranges?
*/
public boolean isIncluded(int value) {
for(Range r: ranges) {
if (r.start <= value && value <= r.end) {
return true;
}
}
return false;
}
@Override
public String toString() {
StringBuffer result = new StringBuffer();
boolean first = true;
for(Range r: ranges) {
if (first) {
first = false;
} else {
result.append(',');
}
result.append(r.start);
result.append('-');
result.append(r.end);
}
return result.toString();
}
}
/**
* Parse the given attribute as a set of integer ranges
* @param name the attribute name
* @param defaultValue the default value if it is not set
* @return a new set of ranges from the configured value
*/
public IntegerRanges getRange(String name, String defaultValue) {
return new IntegerRanges(get(name, defaultValue));
}
/**
* Get the comma delimited values of the <code>name</code> property as
* a collection of <code>String</code>s.
* If no such property is specified then empty collection is returned.
* <p>
* This is an optimized version of {@link #getStrings(String)}
*
* @param name property name.
* @return property value as a collection of <code>String</code>s.
*/
public Collection<String> getStringCollection(String name) {
String valueString = get(name);
return StringUtils.getStringCollection(valueString);
}
/**
* Get the comma delimited values of the <code>name</code> property as
* an array of <code>String</code>s.
* If no such property is specified then <code>null</code> is returned.
*
* @param name property name.
* @return property value as an array of <code>String</code>s,
* or <code>null</code>.
*/
public String[] getStrings(String name) {
String valueString = get(name);
return StringUtils.getStrings(valueString);
}
/**
* Get the comma delimited values of the <code>name</code> property as
* an array of <code>String</code>s.
* If no such property is specified then default value is returned.
*
* @param name property name.
* @param defaultValue The default value
* @return property value as an array of <code>String</code>s,
* or default value.
*/
public String[] getStrings(String name, String... defaultValue) {
String valueString = get(name);
if (valueString == null) {
return defaultValue;
} else {
return StringUtils.getStrings(valueString);
}
}
/**
* Set the array of string values for the <code>name</code> property as
* as comma delimited values.
*
* @param name property name.
* @param values The values
*/
public void setStrings(String name, String... values) {
set(name, StringUtils.arrayToString(values));
}
/**
* Load a class by name.
*
* @param name the class name.
* @return the class object.
* @throws ClassNotFoundException if the class is not found.
*/
public Class<?> getClassByName(String name) throws ClassNotFoundException {
return Class.forName(name, true, classLoader);
}
/**
* Get the value of the <code>name</code> property
* as an array of <code>Class</code>.
* The value of the property specifies a list of comma separated class names.
* If no such property is specified, then <code>defaultValue</code> is
* returned.
*
* @param name the property name.
* @param defaultValue default value.
* @return property value as a <code>Class[]</code>,
* or <code>defaultValue</code>.
*/
public Class<?>[] getClasses(String name, Class<?> ... defaultValue) {
String[] classnames = getStrings(name);
if (classnames == null)
return defaultValue;
try {
Class<?>[] classes = new Class<?>[classnames.length];
for(int i = 0; i < classnames.length; i++) {
classes[i] = getClassByName(classnames[i]);
}
return classes;
} catch (ClassNotFoundException e) {
throw new RuntimeException(e);
}
}
/**
* Get the value of the <code>name</code> property as a <code>Class</code>.
* If no such property is specified, then <code>defaultValue</code> is
* returned.
*
* @param name the class name.
* @param defaultValue default value.
* @return property value as a <code>Class</code>,
* or <code>defaultValue</code>.
*/
public Class<?> getClass(String name, Class<?> defaultValue) {
String valueString = get(name);
if (valueString == null)
return defaultValue;
try {
return getClassByName(valueString);
} catch (ClassNotFoundException e) {
throw new RuntimeException(e);
}
}
/**
* Get the value of the <code>name</code> property as a <code>Class</code>
* implementing the interface specified by <code>xface</code>.
*
* If no such property is specified, then <code>defaultValue</code> is
* returned.
*
* An exception is thrown if the returned class does not implement the named
* interface.
*
* @param name the class name.
* @param defaultValue default value.
* @param xface the interface implemented by the named class.
* @return property value as a <code>Class</code>,
* or <code>defaultValue</code>.
*/
public <U> Class<? extends U> getClass(String name,
Class<? extends U> defaultValue,
Class<U> xface) {
try {
Class<?> theClass = getClass(name, defaultValue);
if (theClass != null && !xface.isAssignableFrom(theClass))
throw new RuntimeException(theClass+" not "+xface.getName());
else if (theClass != null)
return theClass.asSubclass(xface);
else
return null;
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* Set the value of the <code>name</code> property to the name of a
* <code>theClass</code> implementing the given interface <code>xface</code>.
*
* An exception is thrown if <code>theClass</code> does not implement the
* interface <code>xface</code>.
*
* @param name property name.
* @param theClass property value.
* @param xface the interface implemented by the named class.
*/
public void setClass(String name, Class<?> theClass, Class<?> xface) {
if (!xface.isAssignableFrom(theClass))
throw new RuntimeException(theClass+" not "+xface.getName());
set(name, theClass.getName());
}
/**
* Get a local file under a directory named by <i>dirsProp</i> with
* the given <i>path</i>. If <i>dirsProp</i> contains multiple directories,
* then one is chosen based on <i>path</i>'s hash code. If the selected
* directory does not exist, an attempt is made to create it.
*
* @param dirsProp directory in which to locate the file.
* @param path file-path.
* @return local file under the directory with the given path.
*/
public Path getLocalPath(String dirsProp, String path)
throws IOException {
String[] dirs = getStrings(dirsProp);
int hashCode = path.hashCode();
FileSystem fs = FileSystem.getLocal(this);
for (int i = 0; i < dirs.length; i++) { // try each local dir
int index = (hashCode+i & Integer.MAX_VALUE) % dirs.length;
Path file = new Path(dirs[index], path);
Path dir = file.getParent();
if (fs.mkdirs(dir) || fs.exists(dir)) {
return file;
}
}
LOG.warn("Could not make " + path +
" in local directories from " + dirsProp);
for(int i=0; i < dirs.length; i++) {
int index = (hashCode+i & Integer.MAX_VALUE) % dirs.length;
LOG.warn(dirsProp + "[" + index + "]=" + dirs[index]);
}
throw new IOException("No valid local directories in property: "+dirsProp);
}
/**
* Get a local file name under a directory named in <i>dirsProp</i> with
* the given <i>path</i>. If <i>dirsProp</i> contains multiple directories,
* then one is chosen based on <i>path</i>'s hash code. If the selected
* directory does not exist, an attempt is made to create it.
*
* @param dirsProp directory in which to locate the file.
* @param path file-path.
* @return local file under the directory with the given path.
*/
public File getFile(String dirsProp, String path)
throws IOException {
String[] dirs = getStrings(dirsProp);
int hashCode = path.hashCode();
for (int i = 0; i < dirs.length; i++) { // try each local dir
int index = (hashCode+i & Integer.MAX_VALUE) % dirs.length;
File file = new File(dirs[index], path);
File dir = file.getParentFile();
if (dir.exists() || dir.mkdirs()) {
return file;
}
}
throw new IOException("No valid local directories in property: "+dirsProp);
}
/**
* Get the {@link URL} for the named resource.
*
* @param name resource name.
* @return the url for the named resource.
*/
public URL getResource(String name) {
return classLoader.getResource(name);
}
/**
* Get an input stream attached to the configuration resource with the
* given <code>name</code>.
*
* @param name configuration resource name.
* @return an input stream attached to the resource.
*/
public InputStream getConfResourceAsInputStream(String name) {
try {
URL url= getResource(name);
if (url == null) {
LOG.info(name + " not found");
return null;
} else {
LOG.info("found resource " + name + " at " + url);
}
return url.openStream();
} catch (Exception e) {
return null;
}
}
/**
* Get a {@link Reader} attached to the configuration resource with the
* given <code>name</code>.
*
* @param name configuration resource name.
* @return a reader attached to the resource.
*/
public Reader getConfResourceAsReader(String name) {
try {
URL url= getResource(name);
if (url == null) {
LOG.info(name + " not found");
return null;
} else {
LOG.info("found resource " + name + " at " + url);
}
return new InputStreamReader(url.openStream());
} catch (Exception e) {
return null;
}
}
private synchronized Properties getProps() {
if (properties == null) {
properties = new Properties();
loadResources(properties, resources, quietmode);
if (overlay!= null)
properties.putAll(overlay);
}
return properties;
}
/**
* Return the number of keys in the configuration.
*
* @return number of keys in the configuration.
*/
public int size() {
return getProps().size();
}
/**
* Clears all keys from the configuration.
*/
public void clear() {
getProps().clear();
getOverlay().clear();
}
/**
* Get an {@link Iterator} to go through the list of <code>String</code>
* key-value pairs in the configuration.
*
* @return an iterator over the entries.
*/
public Iterator<Map.Entry<String, String>> iterator() {
// Get a copy of just the string to string pairs. After the old object
// methods that allow non-strings to be put into configurations are removed,
// we could replace properties with a Map<String,String> and get rid of this
// code.
Map<String,String> result = new HashMap<String,String>();
for(Map.Entry<Object,Object> item: getProps().entrySet()) {
if (item.getKey() instanceof String &&
item.getValue() instanceof String) {
result.put((String) item.getKey(), (String) item.getValue());
}
}
return result.entrySet().iterator();
}
private void loadResources(Properties properties,
ArrayList resources,
boolean quiet) {
if(loadDefaults) {
for (String resource : defaultResources) {
loadResource(properties, resource, quiet);
}
//support the hadoop-site.xml as a deprecated case
if(getResource("hadoop-site.xml")!=null) {
loadResource(properties, "hadoop-site.xml", quiet);
}
}
for (Object resource : resources) {
loadResource(properties, resource, quiet);
}
}
private void loadResource(Properties properties, Object name, boolean quiet) {
try {
DocumentBuilderFactory docBuilderFactory
= DocumentBuilderFactory.newInstance();
//ignore all comments inside the xml file
docBuilderFactory.setIgnoringComments(true);
//allow includes in the xml file
docBuilderFactory.setNamespaceAware(true);
try {
docBuilderFactory.setXIncludeAware(true);
} catch (UnsupportedOperationException e) {
LOG.error("Failed to set setXIncludeAware(true) for parser "
+ docBuilderFactory
+ ":" + e,
e);
}
DocumentBuilder builder = docBuilderFactory.newDocumentBuilder();
Document doc = null;
Element root = null;
if (name instanceof URL) { // an URL resource
URL url = (URL)name;
if (url != null) {
if (!quiet) {
LOG.info("parsing " + url);
}
doc = builder.parse(url.toString());
}
} else if (name instanceof String) { // a CLASSPATH resource
URL url = getResource((String)name);
if (url != null) {
if (!quiet) {
LOG.info("parsing " + url);
}
doc = builder.parse(url.toString());
}
} else if (name instanceof Path) { // a file resource
// Can't use FileSystem API or we get an infinite loop
// since FileSystem uses Configuration API. Use java.io.File instead.
File file = new File(((Path)name).toUri().getPath())
.getAbsoluteFile();
if (file.exists()) {
if (!quiet) {
LOG.info("parsing " + file);
}
InputStream in = new BufferedInputStream(new FileInputStream(file));
try {
doc = builder.parse(in);
} finally {
in.close();
}
}
} else if (name instanceof InputStream) {
try {
doc = builder.parse((InputStream)name);
} finally {
((InputStream)name).close();
}
} else if (name instanceof Element) {
root = (Element)name;
}
if (doc == null && root == null) {
if (quiet)
return;
throw new RuntimeException(name + " not found");
}
if (root == null) {
root = doc.getDocumentElement();
}
if (!"configuration".equals(root.getTagName()))
LOG.fatal("bad conf file: top-level element not <configuration>");
NodeList props = root.getChildNodes();
for (int i = 0; i < props.getLength(); i++) {
Node propNode = props.item(i);
if (!(propNode instanceof Element))
continue;
Element prop = (Element)propNode;
if ("configuration".equals(prop.getTagName())) {
loadResource(properties, prop, quiet);
continue;
}
if (!"property".equals(prop.getTagName()))
LOG.warn("bad conf file: element not <property>");
NodeList fields = prop.getChildNodes();
String attr = null;
String value = null;
boolean finalParameter = false;
for (int j = 0; j < fields.getLength(); j++) {
Node fieldNode = fields.item(j);
if (!(fieldNode instanceof Element))
continue;
Element field = (Element)fieldNode;
if ("name".equals(field.getTagName()) && field.hasChildNodes())
attr = ((Text)field.getFirstChild()).getData().trim();
if ("value".equals(field.getTagName()) && field.hasChildNodes())
value = ((Text)field.getFirstChild()).getData();
if ("final".equals(field.getTagName()) && field.hasChildNodes())
finalParameter = "true".equals(((Text)field.getFirstChild()).getData());
}
// Ignore this parameter if it has already been marked as 'final'
if (attr != null && value != null) {
if (!finalParameters.contains(attr)) {
properties.setProperty(attr, value);
if (finalParameter)
finalParameters.add(attr);
} else {
LOG.warn(name+":a attempt to override final parameter: "+attr
+"; Ignoring.");
}
}
}
} catch (IOException e) {
LOG.fatal("error parsing conf file: " + e);
throw new RuntimeException(e);
} catch (DOMException e) {
LOG.fatal("error parsing conf file: " + e);
throw new RuntimeException(e);
} catch (SAXException e) {
LOG.fatal("error parsing conf file: " + e);
throw new RuntimeException(e);
} catch (ParserConfigurationException e) {
LOG.fatal("error parsing conf file: " + e);
throw new RuntimeException(e);
}
}
/**
* Write out the non-default properties in this configuration to the give
* {@link OutputStream}.
*
* @param out the output stream to write to.
*/
public void writeXml(OutputStream out) throws IOException {
Properties properties = getProps();
try {
Document doc =
DocumentBuilderFactory.newInstance().newDocumentBuilder().newDocument();
Element conf = doc.createElement("configuration");
doc.appendChild(conf);
conf.appendChild(doc.createTextNode("\n"));
for (Enumeration e = properties.keys(); e.hasMoreElements();) {
String name = (String)e.nextElement();
Object object = properties.get(name);
String value = null;
if (object instanceof String) {
value = (String) object;
}else {
continue;
}
Element propNode = doc.createElement("property");
conf.appendChild(propNode);
Element nameNode = doc.createElement("name");
nameNode.appendChild(doc.createTextNode(name));
propNode.appendChild(nameNode);
Element valueNode = doc.createElement("value");
valueNode.appendChild(doc.createTextNode(value));
propNode.appendChild(valueNode);
conf.appendChild(doc.createTextNode("\n"));
}
DOMSource source = new DOMSource(doc);
StreamResult result = new StreamResult(out);
TransformerFactory transFactory = TransformerFactory.newInstance();
Transformer transformer = transFactory.newTransformer();
transformer.transform(source, result);
} catch (Exception e) {
throw new RuntimeException(e);
}
}
/**
* Get the {@link ClassLoader} for this job.
*
* @return the correct class loader.
*/
public ClassLoader getClassLoader() {
return classLoader;
}
/**
* Set the class loader that will be used to load the various objects.
*
* @param classLoader the new class loader.
*/
public void setClassLoader(ClassLoader classLoader) {
this.classLoader = classLoader;
}
@Override
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append("Configuration: ");
if(loadDefaults) {
toString(defaultResources, sb);
if(resources.size()>0) {
sb.append(", ");
}
}
toString(resources, sb);
return sb.toString();
}
private void toString(List resources, StringBuffer sb) {
ListIterator i = resources.listIterator();
while (i.hasNext()) {
if (i.nextIndex() != 0) {
sb.append(", ");
}
sb.append(i.next());
}
}
/**
* Set the quietness-mode.
*
* In the quiet-mode, error and informational messages might not be logged.
*
* @param quietmode <code>true</code> to set quiet-mode on, <code>false</code>
* to turn it off.
*/
public synchronized void setQuietMode(boolean quietmode) {
this.quietmode = quietmode;
}
/** For debugging. List non-default properties to the terminal and exit. */
public static void main(String[] args) throws Exception {
new Configuration().writeXml(System.out);
}
@Override
public void readFields(DataInput in) throws IOException {
clear();
int size = WritableUtils.readVInt(in);
for(int i=0; i < size; ++i) {
set(org.apache.hadoop.io.Text.readString(in),
org.apache.hadoop.io.Text.readString(in));
}
}
//@Override
public void write(DataOutput out) throws IOException {
Properties props = getProps();
WritableUtils.writeVInt(out, props.size());
for(Map.Entry<Object, Object> item: props.entrySet()) {
org.apache.hadoop.io.Text.writeString(out, (String) item.getKey());
org.apache.hadoop.io.Text.writeString(out, (String) item.getValue());
}
}
}