JDK8/Java8源码在线阅读
/*
* Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
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package javax.naming.ldap;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.ArrayList;
import java.util.Locale;
import java.util.Collections;
import javax.naming.InvalidNameException;
import javax.naming.directory.BasicAttributes;
import javax.naming.directory.Attributes;
import javax.naming.directory.Attribute;
import javax.naming.NamingEnumeration;
import javax.naming.NamingException;
import java.io.Serializable;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.io.IOException;
/**
* This class represents a relative distinguished name, or RDN, which is a
* component of a distinguished name as specified by
* <a href="http://www.ietf.org/rfc/rfc2253.txt">RFC 2253</a>.
* An example of an RDN is "OU=Sales+CN=J.Smith". In this example,
* the RDN consist of multiple attribute type/value pairs. The
* RDN is parsed as described in the class description for
* {@link javax.naming.ldap.LdapName <tt>LdapName</tt>}.
* <p>
* The Rdn class represents an RDN as attribute type/value mappings,
* which can be viewed using
* {@link javax.naming.directory.Attributes Attributes}.
* In addition, it contains convenience methods that allow easy retrieval
* of type and value when the Rdn consist of a single type/value pair,
* which is how it appears in a typical usage.
* It also contains helper methods that allow escaping of the unformatted
* attribute value and unescaping of the value formatted according to the
* escaping syntax defined in RFC2253. For methods that take or return
* attribute value as an Object, the value is either a String
* (in unescaped form) or a byte array.
* <p>
* <code>Rdn</code> will properly parse all valid RDNs, but
* does not attempt to detect all possible violations when parsing
* invalid RDNs. It is "generous" in accepting invalid RDNs.
* The "validity" of a name is determined ultimately when it
* is supplied to an LDAP server, which may accept or
* reject the name based on factors such as its schema information
* and interoperability considerations.
*
* <p>
* The following code example shows how to construct an Rdn using the
* constructor that takes type and value as arguments:
* <pre>
* Rdn rdn = new Rdn("cn", "Juicy, Fruit");
* System.out.println(rdn.toString());
* </pre>
* The last line will print <tt>cn=Juicy\, Fruit</tt>. The
* {@link #unescapeValue(String) <tt>unescapeValue()</tt>} method can be
* used to unescape the escaped comma resulting in the original
* value <tt>"Juicy, Fruit"</tt>. The {@link #escapeValue(Object)
* <tt>escapeValue()</tt>} method adds the escape back preceding the comma.
* <p>
* This class can be instantiated by a string representation
* of the RDN defined in RFC 2253 as shown in the following code example:
* <pre>
* Rdn rdn = new Rdn("cn=Juicy\\, Fruit");
* System.out.println(rdn.toString());
* </pre>
* The last line will print <tt>cn=Juicy\, Fruit</tt>.
* <p>
* Concurrent multithreaded read-only access of an instance of
* <tt>Rdn</tt> need not be synchronized.
* <p>
* Unless otherwise noted, the behavior of passing a null argument
* to a constructor or method in this class will cause NullPointerException
* to be thrown.
*
* @since 1.5
*/
public class Rdn implements Serializable, Comparable<Object> {
private transient ArrayList<RdnEntry> entries;
// The common case.
private static final int DEFAULT_SIZE = 1;
private static final long serialVersionUID = -5994465067210009656L;
/**
* Constructs an Rdn from the given attribute set. See
* {@link javax.naming.directory.Attributes Attributes}.
* <p>
* The string attribute values are not interpreted as
* <a href="http://www.ietf.org/rfc/rfc2253.txt">RFC 2253</a>
* formatted RDN strings. That is, the values are used
* literally (not parsed) and assumed to be unescaped.
*
* @param attrSet The non-null and non-empty attributes containing
* type/value mappings.
* @throws InvalidNameException If contents of <tt>attrSet</tt> cannot
* be used to construct a valid RDN.
*/
public Rdn(Attributes attrSet) throws InvalidNameException {
if (attrSet.size() == 0) {
throw new InvalidNameException("Attributes cannot be empty");
}
entries = new ArrayList<>(attrSet.size());
NamingEnumeration<? extends Attribute> attrs = attrSet.getAll();
try {
for (int nEntries = 0; attrs.hasMore(); nEntries++) {
RdnEntry entry = new RdnEntry();
Attribute attr = attrs.next();
entry.type = attr.getID();
entry.value = attr.get();
entries.add(nEntries, entry);
}
} catch (NamingException e) {
InvalidNameException e2 = new InvalidNameException(
e.getMessage());
e2.initCause(e);
throw e2;
}
sort(); // arrange entries for comparison
}
/**
* Constructs an Rdn from the given string.
* This constructor takes a string formatted according to the rules
* defined in <a href="http://www.ietf.org/rfc/rfc2253.txt">RFC 2253</a>
* and described in the class description for
* {@link javax.naming.ldap.LdapName}.
*
* @param rdnString The non-null and non-empty RFC2253 formatted string.
* @throws InvalidNameException If a syntax error occurs during
* parsing of the rdnString.
*/
public Rdn(String rdnString) throws InvalidNameException {
entries = new ArrayList<>(DEFAULT_SIZE);
(new Rfc2253Parser(rdnString)).parseRdn(this);
}
/**
* Constructs an Rdn from the given <tt>rdn</tt>.
* The contents of the <tt>rdn</tt> are simply copied into the newly
* created Rdn.
* @param rdn The non-null Rdn to be copied.
*/
public Rdn(Rdn rdn) {
entries = new ArrayList<>(rdn.entries.size());
entries.addAll(rdn.entries);
}
/**
* Constructs an Rdn from the given attribute type and
* value.
* The string attribute values are not interpreted as
* <a href="http://www.ietf.org/rfc/rfc2253.txt">RFC 2253</a>
* formatted RDN strings. That is, the values are used
* literally (not parsed) and assumed to be unescaped.
*
* @param type The non-null and non-empty string attribute type.
* @param value The non-null and non-empty attribute value.
* @throws InvalidNameException If type/value cannot be used to
* construct a valid RDN.
* @see #toString()
*/
public Rdn(String type, Object value) throws InvalidNameException {
if (value == null) {
throw new NullPointerException("Cannot set value to null");
}
if (type.equals("") || isEmptyValue(value)) {
throw new InvalidNameException(
"type or value cannot be empty, type:" + type +
" value:" + value);
}
entries = new ArrayList<>(DEFAULT_SIZE);
put(type, value);
}
private boolean isEmptyValue(Object val) {
return ((val instanceof String) && val.equals("")) ||
((val instanceof byte[]) && (((byte[]) val).length == 0));
}
// An empty constructor used by the parser
Rdn() {
entries = new ArrayList<>(DEFAULT_SIZE);
}
/*
* Adds the given attribute type and value to this Rdn.
* The string attribute values are not interpreted as
* <a href="http://www.ietf.org/rfc/rfc2253.txt">RFC 2253</a>
* formatted RDN strings. That is the values are used
* literally (not parsed) and assumed to be unescaped.
*
* @param type The non-null and non-empty string attribute type.
* @param value The non-null and non-empty attribute value.
* @return The updated Rdn, not a new one. Cannot be null.
* @see #toString()
*/
Rdn put(String type, Object value) {
// create new Entry
RdnEntry newEntry = new RdnEntry();
newEntry.type = type;
if (value instanceof byte[]) { // clone the byte array
newEntry.value = ((byte[]) value).clone();
} else {
newEntry.value = value;
}
entries.add(newEntry);
return this;
}
void sort() {
if (entries.size() > 1) {
Collections.sort(entries);
}
}
/**
* Retrieves one of this Rdn's value.
* This is a convenience method for obtaining the value,
* when the RDN contains a single type and value mapping,
* which is the common RDN usage.
* <p>
* For a multi-valued RDN, this method returns value corresponding
* to the type returned by {@link #getType() getType()} method.
*
* @return The non-null attribute value.
*/
public Object getValue() {
return entries.get(0).getValue();
}
/**
* Retrieves one of this Rdn's type.
* This is a convenience method for obtaining the type,
* when the RDN contains a single type and value mapping,
* which is the common RDN usage.
* <p>
* For a multi-valued RDN, the type/value pairs have
* no specific order defined on them. In that case, this method
* returns type of one of the type/value pairs.
* The {@link #getValue() getValue()} method returns the
* value corresponding to the type returned by this method.
*
* @return The non-null attribute type.
*/
public String getType() {
return entries.get(0).getType();
}
/**
* Returns this Rdn as a string represented in a format defined by
* <a href="http://www.ietf.org/rfc/rfc2253.txt">RFC 2253</a> and described
* in the class description for {@link javax.naming.ldap.LdapName LdapName}.
*
* @return The string representation of the Rdn.
*/
public String toString() {
StringBuilder builder = new StringBuilder();
int size = entries.size();
if (size > 0) {
builder.append(entries.get(0));
}
for (int next = 1; next < size; next++) {
builder.append('+');
builder.append(entries.get(next));
}
return builder.toString();
}
/**
* Compares this Rdn with the specified Object for order.
* Returns a negative integer, zero, or a positive integer as this
* Rdn is less than, equal to, or greater than the given Object.
* <p>
* If obj is null or not an instance of Rdn, ClassCastException
* is thrown.
* <p>
* The attribute type and value pairs of the RDNs are lined up
* against each other and compared lexicographically. The order of
* components in multi-valued Rdns (such as "ou=Sales+cn=Bob") is not
* significant.
*
* @param obj The non-null object to compare against.
* @return A negative integer, zero, or a positive integer as this Rdn
* is less than, equal to, or greater than the given Object.
* @exception ClassCastException if obj is null or not a Rdn.
*/
public int compareTo(Object obj) {
if (!(obj instanceof Rdn)) {
throw new ClassCastException("The obj is not a Rdn");
}
if (obj == this) {
return 0;
}
Rdn that = (Rdn) obj;
int minSize = Math.min(entries.size(), that.entries.size());
for (int i = 0; i < minSize; i++) {
// Compare a single pair of type/value pairs.
int diff = entries.get(i).compareTo(that.entries.get(i));
if (diff != 0) {
return diff;
}
}
return (entries.size() - that.entries.size()); // longer RDN wins
}
/**
* Compares the specified Object with this Rdn for equality.
* Returns true if the given object is also a Rdn and the two Rdns
* represent the same attribute type and value mappings. The order of
* components in multi-valued Rdns (such as "ou=Sales+cn=Bob") is not
* significant.
* <p>
* Type and value equality matching is done as below:
* <ul>
* <li> The types are compared for equality with their case ignored.
* <li> String values with different but equivalent usage of quoting,
* escaping, or UTF8-hex-encoding are considered equal.
* The case of the values is ignored during the comparison.
* </ul>
* <p>
* If obj is null or not an instance of Rdn, false is returned.
* <p>
* @param obj object to be compared for equality with this Rdn.
* @return true if the specified object is equal to this Rdn.
* @see #hashCode()
*/
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof Rdn)) {
return false;
}
Rdn that = (Rdn) obj;
if (entries.size() != that.size()) {
return false;
}
for (int i = 0; i < entries.size(); i++) {
if (!entries.get(i).equals(that.entries.get(i))) {
return false;
}
}
return true;
}
/**
* Returns the hash code of this RDN. Two RDNs that are
* equal (according to the equals method) will have the same
* hash code.
*
* @return An int representing the hash code of this Rdn.
* @see #equals
*/
public int hashCode() {
// Sum up the hash codes of the components.
int hash = 0;
// For each type/value pair...
for (int i = 0; i < entries.size(); i++) {
hash += entries.get(i).hashCode();
}
return hash;
}
/**
* Retrieves the {@link javax.naming.directory.Attributes Attributes}
* view of the type/value mappings contained in this Rdn.
*
* @return The non-null attributes containing the type/value
* mappings of this Rdn.
*/
public Attributes toAttributes() {
Attributes attrs = new BasicAttributes(true);
for (int i = 0; i < entries.size(); i++) {
RdnEntry entry = entries.get(i);
Attribute attr = attrs.put(entry.getType(), entry.getValue());
if (attr != null) {
attr.add(entry.getValue());
attrs.put(attr);
}
}
return attrs;
}
private static class RdnEntry implements Comparable<RdnEntry> {
private String type;
private Object value;
// If non-null, a cannonical representation of the value suitable
// for comparison using String.compareTo()
private String comparable = null;
String getType() {
return type;
}
Object getValue() {
return value;
}
public int compareTo(RdnEntry that) {
int diff = type.compareToIgnoreCase(that.type);
if (diff != 0) {
return diff;
}
if (value.equals(that.value)) { // try shortcut
return 0;
}
return getValueComparable().compareTo(
that.getValueComparable());
}
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof RdnEntry)) {
return false;
}
// Any change here must be reflected in hashCode()
RdnEntry that = (RdnEntry) obj;
return (type.equalsIgnoreCase(that.type)) &&
(getValueComparable().equals(
that.getValueComparable()));
}
public int hashCode() {
return (type.toUpperCase(Locale.ENGLISH).hashCode() +
getValueComparable().hashCode());
}
public String toString() {
return type + "=" + escapeValue(value);
}
private String getValueComparable() {
if (comparable != null) {
return comparable; // return cached result
}
// cache result
if (value instanceof byte[]) {
comparable = escapeBinaryValue((byte[]) value);
} else {
comparable = ((String) value).toUpperCase(Locale.ENGLISH);
}
return comparable;
}
}
/**
* Retrieves the number of attribute type/value pairs in this Rdn.
* @return The non-negative number of type/value pairs in this Rdn.
*/
public int size() {
return entries.size();
}
/**
* Given the value of an attribute, returns a string escaped according
* to the rules specified in
* <a href="http://www.ietf.org/rfc/rfc2253.txt">RFC 2253</a>.
* <p>
* For example, if the val is "Sue, Grabbit and Runn", the escaped
* value returned by this method is "Sue\, Grabbit and Runn".
* <p>
* A string value is represented as a String and binary value
* as a byte array.
*
* @param val The non-null object to be escaped.
* @return Escaped string value.
* @throws ClassCastException if val is is not a String or byte array.
*/
public static String escapeValue(Object val) {
return (val instanceof byte[])
? escapeBinaryValue((byte[])val)
: escapeStringValue((String)val);
}
/*
* Given the value of a string-valued attribute, returns a
* string suitable for inclusion in a DN. This is accomplished by
* using backslash (\) to escape the following characters:
* leading and trailing whitespace
* , = + < > # ; " \
*/
private static final String escapees = ",=+<>#;\"\\";
private static String escapeStringValue(String val) {
char[] chars = val.toCharArray();
StringBuilder builder = new StringBuilder(2 * val.length());
// Find leading and trailing whitespace.
int lead; // index of first char that is not leading whitespace
for (lead = 0; lead < chars.length; lead++) {
if (!isWhitespace(chars[lead])) {
break;
}
}
int trail; // index of last char that is not trailing whitespace
for (trail = chars.length - 1; trail >= 0; trail--) {
if (!isWhitespace(chars[trail])) {
break;
}
}
for (int i = 0; i < chars.length; i++) {
char c = chars[i];
if ((i < lead) || (i > trail) || (escapees.indexOf(c) >= 0)) {
builder.append('\\');
}
builder.append(c);
}
return builder.toString();
}
/*
* Given the value of a binary attribute, returns a string
* suitable for inclusion in a DN (such as "#CEB1DF80").
* TBD: This method should actually generate the ber encoding
* of the binary value
*/
private static String escapeBinaryValue(byte[] val) {
StringBuilder builder = new StringBuilder(1 + 2 * val.length);
builder.append("#");
for (int i = 0; i < val.length; i++) {
byte b = val[i];
builder.append(Character.forDigit(0xF & (b >>> 4), 16));
builder.append(Character.forDigit(0xF & b, 16));
}
return builder.toString();
}
/**
* Given an attribute value string formated according to the rules
* specified in
* <a href="http://www.ietf.org/rfc/rfc2253.txt">RFC 2253</a>,
* returns the unformated value. Escapes and quotes are
* stripped away, and hex-encoded UTF-8 is converted to equivalent
* UTF-16 characters. Returns a string value as a String, and a
* binary value as a byte array.
* <p>
* Legal and illegal values are defined in RFC 2253.
* This method is generous in accepting the values and does not
* catch all illegal values.
* Therefore, passing in an illegal value might not necessarily
* trigger an <tt>IllegalArgumentException</tt>.
*
* @param val The non-null string to be unescaped.
* @return Unescaped value.
* @throws IllegalArgumentException When an Illegal value
* is provided.
*/
public static Object unescapeValue(String val) {
char[] chars = val.toCharArray();
int beg = 0;
int end = chars.length;
// Trim off leading and trailing whitespace.
while ((beg < end) && isWhitespace(chars[beg])) {
++beg;
}
while ((beg < end) && isWhitespace(chars[end - 1])) {
--end;
}
// Add back the trailing whitespace with a preceding '\'
// (escaped or unescaped) that was taken off in the above
// loop. Whether or not to retain this whitespace is decided below.
if (end != chars.length &&
(beg < end) &&
chars[end - 1] == '\\') {
end++;
}
if (beg >= end) {
return "";
}
if (chars[beg] == '#') {
// Value is binary (eg: "#CEB1DF80").
return decodeHexPairs(chars, ++beg, end);
}
// Trim off quotes.
if ((chars[beg] == '\"') && (chars[end - 1] == '\"')) {
++beg;
--end;
}
StringBuilder builder = new StringBuilder(end - beg);
int esc = -1; // index of the last escaped character
for (int i = beg; i < end; i++) {
if ((chars[i] == '\\') && (i + 1 < end)) {
if (!Character.isLetterOrDigit(chars[i + 1])) {
++i; // skip backslash
builder.append(chars[i]); // snarf escaped char
esc = i;
} else {
// Convert hex-encoded UTF-8 to 16-bit chars.
byte[] utf8 = getUtf8Octets(chars, i, end);
if (utf8.length > 0) {
try {
builder.append(new String(utf8, "UTF8"));
} catch (java.io.UnsupportedEncodingException e) {
// shouldn't happen
}
i += utf8.length * 3 - 1;
} else { // no utf8 bytes available, invalid DN
// '/' has no meaning, throw exception
throw new IllegalArgumentException(
"Not a valid attribute string value:" +
val + ",improper usage of backslash");
}
}
} else {
builder.append(chars[i]); // snarf unescaped char
}
}
// Get rid of the unescaped trailing whitespace with the
// preceding '\' character that was previously added back.
int len = builder.length();
if (isWhitespace(builder.charAt(len - 1)) && esc != (end - 1)) {
builder.setLength(len - 1);
}
return builder.toString();
}
/*
* Given an array of chars (with starting and ending indexes into it)
* representing bytes encoded as hex-pairs (such as "CEB1DF80"),
* returns a byte array containing the decoded bytes.
*/
private static byte[] decodeHexPairs(char[] chars, int beg, int end) {
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