/*
* Copyright 2002-2013 the original author or authors.
*
* 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
*
* 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.gridkit.jvmtool.cmd;
import java.io.File;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.StringTokenizer;
import java.util.concurrent.ConcurrentHashMap;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* PathMatcher implementation for Ant-style path patterns. Examples are provided below.
*
* <p>Part of this mapping code has been kindly borrowed from <a href="http://ant.apache.org">Apache Ant</a>.
*
* <p>The mapping matches URLs using the following rules:<br> <ul> <li>? matches one character</li> <li>* matches zero
* or more characters</li> <li>** matches zero or more 'directories' in a path</li> </ul>
*
* <p>Some examples:<br> <ul> <li>{@code com/t?st.jsp} - matches {@code com/test.jsp} but also
* {@code com/tast.jsp} or {@code com/txst.jsp}</li> <li>{@code com/*.jsp} - matches all
* {@code .jsp} files in the {@code com} directory</li> <li>{@code com/**/test.jsp} - matches all
* {@code test.jsp} files underneath the {@code com} path</li> <li>{@code org/springframework/**/*.jsp}
* - matches all {@code .jsp} files underneath the {@code org/springframework} path</li>
* <li>{@code org/**/servlet/bla.jsp} - matches {@code org/springframework/servlet/bla.jsp} but also
* {@code org/springframework/testing/servlet/bla.jsp} and {@code org/servlet/bla.jsp}</li> </ul>
*
* @author Alef Arendsen
* @author Juergen Hoeller
* @author Rob Harrop
* @author Arjen Poutsma
* @author Rossen Stoyanchev
* @since 16.07.2003
*/
class AntPathMatcher {
private static final Pattern VARIABLE_PATTERN = Pattern.compile("\\{[^/]+?\\}");
/** Default path separator: "/" */
public static final String DEFAULT_PATH_SEPARATOR = "/";
private String pathSeparator = DEFAULT_PATH_SEPARATOR;
private final Map<String, AntPathStringMatcher> stringMatcherCache =
new ConcurrentHashMap<String, AntPathStringMatcher>(256);
private boolean trimTokens = true;
public Iterable<File> findFiles(File relativeRoot, String pattern) {
StringBuilder sb = new StringBuilder();
for(int i = 0; i != pattern.length(); ++i) {
char c = pattern.charAt(i);
if (c == '?' || c == '*') {
sb.setLength(sb.lastIndexOf(pathSeparator));
break;
}
sb.append(c);
}
if (sb.length() == pattern.length()) {
File f = path2file(relativeRoot, pattern);
if (f.exists()) {
return Collections.singleton(f);
}
else {
return Collections.emptyList();
}
}
else {
String base = sb.toString();
File root = path2file(relativeRoot, base);
return findFiles(root, base, pattern);
}
}
protected File path2file(File relativeRoot, String pattern) {
File f;
if (pattern.startsWith(pathSeparator) || (pattern.length() > 2 && pattern.charAt(1) == ':')) {
f = new File(pattern);
}
else {
f = new File(relativeRoot, pattern);
}
return f;
}
protected Iterable<File> findFiles(final File root, final String prefix, final String pattern) {
return new Iterable<File>() {
@Override
public Iterator<File> iterator() {
return new SeekerIterator(root, prefix, pattern);
}
};
}
/** Set the path separator to use for pattern parsing. Default is "/", as in Ant. */
public void setPathSeparator(String pathSeparator) {
this.pathSeparator = (pathSeparator != null ? pathSeparator : DEFAULT_PATH_SEPARATOR);
}
/** Whether to trim tokenized paths and patterns. */
public void setTrimTokens(boolean trimTokens) {
this.trimTokens = trimTokens;
}
public boolean isPattern(String path) {
return (path.indexOf('*') != -1 || path.indexOf('?') != -1);
}
public boolean match(String pattern, String path) {
return doMatch(pattern, path, true, null);
}
public boolean matchStart(String pattern, String path) {
return doMatch(pattern, path, false, null);
}
/**
* Actually match the given {@code path} against the given {@code pattern}.
* @param pattern the pattern to match against
* @param path the path String to test
* @param fullMatch whether a full pattern match is required (else a pattern match
* as far as the given base path goes is sufficient)
* @return {@code true} if the supplied {@code path} matched, {@code false} if it didn't
*/
protected boolean doMatch(String pattern, String path, boolean fullMatch,
Map<String, String> uriTemplateVariables) {
if (path.startsWith(this.pathSeparator) != pattern.startsWith(this.pathSeparator)) {
return false;
}
String[] pattDirs = tokenizeToStringArray(pattern, this.pathSeparator, this.trimTokens, true);
String[] pathDirs = tokenizeToStringArray(path, this.pathSeparator, this.trimTokens, true);
int pattIdxStart = 0;
int pattIdxEnd = pattDirs.length - 1;
int pathIdxStart = 0;
int pathIdxEnd = pathDirs.length - 1;
// Match all elements up to the first **
while (pattIdxStart <= pattIdxEnd && pathIdxStart <= pathIdxEnd) {
String patDir = pattDirs[pattIdxStart];
if ("**".equals(patDir)) {
break;
}
if (!matchStrings(patDir, pathDirs[pathIdxStart], uriTemplateVariables)) {
return false;
}
pattIdxStart++;
pathIdxStart++;
}
if (pathIdxStart > pathIdxEnd) {
// Path is exhausted, only match if rest of pattern is * or **'s
if (pattIdxStart > pattIdxEnd) {
return (pattern.endsWith(this.pathSeparator) ? path.endsWith(this.pathSeparator) :
!path.endsWith(this.pathSeparator));
}
if (!fullMatch) {
return true;
}
if (pattIdxStart == pattIdxEnd && pattDirs[pattIdxStart].equals("*") && path.endsWith(this.pathSeparator)) {
return true;
}
for (int i = pattIdxStart; i <= pattIdxEnd; i++) {
if (!pattDirs[i].equals("**")) {
return false;
}
}
return true;
}
else if (pattIdxStart > pattIdxEnd) {
// String not exhausted, but pattern is. Failure.
return false;
}
else if (!fullMatch && "**".equals(pattDirs[pattIdxStart])) {
// Path start definitely matches due to "**" part in pattern.
return true;
}
// up to last '**'
while (pattIdxStart <= pattIdxEnd && pathIdxStart <= pathIdxEnd) {
String patDir = pattDirs[pattIdxEnd];
if (patDir.equals("**")) {
break;
}
if (!matchStrings(patDir, pathDirs[pathIdxEnd], uriTemplateVariables)) {
return false;
}
pattIdxEnd--;
pathIdxEnd--;
}
if (pathIdxStart > pathIdxEnd) {
// String is exhausted
for (int i = pattIdxStart; i <= pattIdxEnd; i++) {
if (!pattDirs[i].equals("**")) {
return false;
}
}
return true;
}
while (pattIdxStart != pattIdxEnd && pathIdxStart <= pathIdxEnd) {
int patIdxTmp = -1;
for (int i = pattIdxStart + 1; i <= pattIdxEnd; i++) {
if (pattDirs[i].equals("**")) {
patIdxTmp = i;
break;
}
}
if (patIdxTmp == pattIdxStart + 1) {
// '**/**' situation, so skip one
pattIdxStart++;
continue;
}
// Find the pattern between padIdxStart & padIdxTmp in str between
// strIdxStart & strIdxEnd
int patLength = (patIdxTmp - pattIdxStart - 1);
int strLength = (pathIdxEnd - pathIdxStart + 1);
int foundIdx = -1;
strLoop:
for (int i = 0; i <= strLength - patLength; i++) {
for (int j = 0; j < patLength; j++) {
String subPat = pattDirs[pattIdxStart + j + 1];
String subStr = pathDirs[pathIdxStart + i + j];
if (!matchStrings(subPat, subStr, uriTemplateVariables)) {
continue strLoop;
}
}
foundIdx = pathIdxStart + i;
break;
}
if (foundIdx == -1) {
return false;
}
pattIdxStart = patIdxTmp;
pathIdxStart = foundIdx + patLength;
}
for (int i = pattIdxStart; i <= pattIdxEnd; i++) {
if (!pattDirs[i].equals("**")) {
return false;
}
}
return true;
}
/**
* Tests whether or not a string matches against a pattern. The pattern may contain two special characters:
* <br>'*' means zero or more characters
* <br>'?' means one and only one character
* @param pattern pattern to match against. Must not be {@code null}.
* @param str string which must be matched against the pattern. Must not be {@code null}.
* @return {@code true} if the string matches against the pattern, or {@code false} otherwise.
*/
private boolean matchStrings(String pattern, String str, Map<String, String> uriTemplateVariables) {
AntPathStringMatcher matcher = this.stringMatcherCache.get(pattern);
if (matcher == null) {
matcher = new AntPathStringMatcher(pattern);
this.stringMatcherCache.put(pattern, matcher);
}
return matcher.matchStrings(str, uriTemplateVariables);
}
/**
* Given a pattern and a full path, determine the pattern-mapped part. <p>For example: <ul>
* <li>'{@code /docs/cvs/commit.html}' and '{@code /docs/cvs/commit.html} -> ''</li>
* <li>'{@code /docs/*}' and '{@code /docs/cvs/commit} -> '{@code cvs/commit}'</li>
* <li>'{@code /docs/cvs/*.html}' and '{@code /docs/cvs/commit.html} -> '{@code commit.html}'</li>
* <li>'{@code /docs/**}' and '{@code /docs/cvs/commit} -> '{@code cvs/commit}'</li>
* <li>'{@code /docs/**\/*.html}' and '{@code /docs/cvs/commit.html} -> '{@code cvs/commit.html}'</li>
* <li>'{@code /*.html}' and '{@code /docs/cvs/commit.html} -> '{@code docs/cvs/commit.html}'</li>
* <li>'{@code *.html}' and '{@code /docs/cvs/commit.html} -> '{@code /docs/cvs/commit.html}'</li>
* <li>'{@code *}' and '{@code /docs/cvs/commit.html} -> '{@code /docs/cvs/commit.html}'</li> </ul>
* <p>Assumes that {@link #match} returns {@code true} for '{@code pattern}' and '{@code path}', but
* does <strong>not</strong> enforce this.
*/
public String extractPathWithinPattern(String pattern, String path) {
String[] patternParts = tokenizeToStringArray(pattern, this.pathSeparator, this.trimTokens, true);
String[] pathParts = tokenizeToStringArray(path, this.pathSeparator, this.trimTokens, true);
StringBuilder builder = new StringBuilder();
// Add any path parts that have a wildcarded pattern part.
int puts = 0;
for (int i = 0; i < patternParts.length; i++) {
String patternPart = patternParts[i];
if ((patternPart.indexOf('*') > -1 || patternPart.indexOf('?') > -1) && pathParts.length >= i + 1) {
if (puts > 0 || (i == 0 && !pattern.startsWith(this.pathSeparator))) {
builder.append(this.pathSeparator);
}
builder.append(pathParts[i]);
puts++;
}
}
// Append any trailing path parts.
for (int i = patternParts.length; i < pathParts.length; i++) {
if (puts > 0 || i > 0) {
builder.append(this.pathSeparator);
}
builder.append(pathParts[i]);
}
return builder.toString();
}
public Map<String, String> extractUriTemplateVariables(String pattern, String path) {
Map<String, String> variables = new LinkedHashMap<String, String>();
boolean result = doMatch(pattern, path, true, variables);
if (!result) {
throw new IllegalArgumentException("Pattern \"" + pattern + "\" is not a match for \"" + path + "\"");
}
return variables;
}
/**
* Combines two patterns into a new pattern that is returned.
* <p>This implementation simply concatenates the two patterns, unless the first pattern
* contains a file extension match (such as {@code *.html}. In that case, the second pattern
* should be included in the first, or an {@code IllegalArgumentException} is thrown.
* <p>For example: <table>
* <tr><th>Pattern 1</th><th>Pattern 2</th><th>Result</th></tr> <tr><td>/hotels</td><td>{@code
* null}</td><td>/hotels</td></tr> <tr><td>{@code null}</td><td>/hotels</td><td>/hotels</td></tr>
* <tr><td>/hotels</td><td>/bookings</td><td>/hotels/bookings</td></tr> <tr><td>/hotels</td><td>bookings</td><td>/hotels/bookings</td></tr>
* <tr><td>/hotels/*</td><td>/bookings</td><td>/hotels/bookings</td></tr> <tr><td>/hotels/**</td><td>/bookings</td><td>/hotels/**/bookings</td></tr>
* <tr><td>/hotels</td><td>{hotel}</td><td>/hotels/{hotel}</td></tr> <tr><td>/hotels/*</td><td>{hotel}</td><td>/hotels/{hotel}</td></tr>
* <tr><td>/hotels/**</td><td>{hotel}</td><td>/hotels/**/{hotel}</td></tr>
* <tr><td>/*.html</td><td>/hotels.html</td><td>/hotels.html</td></tr> <tr><td>/*.html</td><td>/hotels</td><td>/hotels.html</td></tr>
* <tr><td>/*.html</td><td>/*.txt</td><td>IllegalArgumentException</td></tr> </table>
* @param pattern1 the first pattern
* @param pattern2 the second pattern
* @return the combination of the two patterns
* @throws IllegalArgumentException when the two patterns cannot be combined
*/
public String combine(String pattern1, String pattern2) {
if (!hasText(pattern1) && !hasText(pattern2)) {
return "";
}
else if (!hasText(pattern1)) {
return pattern2;
}
else if (!hasText(pattern2)) {
return pattern1;
}
boolean pattern1ContainsUriVar = pattern1.indexOf('{') != -1;
if (!pattern1.equals(pattern2) && !pattern1ContainsUriVar && match(pattern1, pattern2)) {
// /* + /hotel -> /hotel ; "/*.*" + "/*.html" -> /*.html
// However /user + /user -> /usr/user ; /{foo} + /bar -> /{foo}/bar
return pattern2;
}
else if (pattern1.endsWith("/*")) {
if (pattern2.startsWith("/")) {
// /hotels/* + /booking -> /hotels/booking
return pattern1.substring(0, pattern1.length() - 1) + pattern2.substring(1);
}
else {
// /hotels/* + booking -> /hotels/booking
return pattern1.substring(0, pattern1.length() - 1) + pattern2;
}
}
else if (pattern1.endsWith("/**")) {
if (pattern2.startsWith("/")) {
// /hotels/** + /booking -> /hotels/**/booking
return pattern1 + pattern2;
}
else {
// /hotels/** + booking -> /hotels/**/booking
return pattern1 + "/" + pattern2;
}
}
else {
int dotPos1 = pattern1.indexOf('.');
if (dotPos1 == -1 || pattern1ContainsUriVar) {
// simply concatenate the two patterns
if (pattern1.endsWith("/") || pattern2.startsWith("/")) {
return pattern1 + pattern2;
}
else {
return pattern1 + "/" + pattern2;
}
}
String fileName1 = pattern1.substring(0, dotPos1);
String extension1 = pattern1.substring(dotPos1);
String fileName2;
String extension2;
int dotPos2 = pattern2.indexOf('.');
if (dotPos2 != -1) {
fileName2 = pattern2.substring(0, dotPos2);
extension2 = pattern2.substring(dotPos2);
}
else {
fileName2 = pattern2;
extension2 = "";
}
String fileName = fileName1.endsWith("*") ? fileName2 : fileName1;
String extension = extension1.startsWith("*") ? extension2 : extension1;
return fileName + extension;
}
}
/**
* Given a full path, returns a {@link Comparator} suitable for sorting patterns in order of explicitness.
* <p>The returned {@code Comparator} will {@linkplain java.util.Collections#sort(java.util.List,
* java.util.Comparator) sort} a list so that more specific patterns (without uri templates or wild cards) come before
* generic patterns. So given a list with the following patterns: <ol> <li>{@code /hotels/new}</li>
* <li>{@code /hotels/{hotel}}</li> <li>{@code /hotels/*}</li> </ol> the returned comparator will sort this
* list so that the order will be as indicated.
* <p>The full path given as parameter is used to test for exact matches. So when the given path is {@code /hotels/2},
* the pattern {@code /hotels/2} will be sorted before {@code /hotels/1}.
* @param path the full path to use for comparison
* @return a comparator capable of sorting patterns in order of explicitness
*/
public Comparator<String> getPatternComparator(String path) {
return new AntPatternComparator(path);
}
private static class AntPatternComparator implements Comparator<String> {
private final String path;
private AntPatternComparator(String path) {
this.path = path;
}
public int compare(String pattern1, String pattern2) {
if (pattern1 == null && pattern2 == null) {
return 0;
}
else if (pattern1 == null) {
return 1;
}
else if (pattern2 == null) {
return -1;
}
boolean pattern1EqualsPath = pattern1.equals(path);
boolean pattern2EqualsPath = pattern2.equals(path);
if (pattern1EqualsPath && pattern2EqualsPath) {
return 0;
}
else if (pattern1EqualsPath) {
return -1;
}
else if (pattern2EqualsPath) {
return 1;
}
int wildCardCount1 = getWildCardCount(pattern1);
int wildCardCount2 = getWildCardCount(pattern2);
int bracketCount1 = countOccurrencesOf(pattern1, "{");
int bracketCount2 = countOccurrencesOf(pattern2, "{");
int totalCount1 = wildCardCount1 + bracketCount1;
int totalCount2 = wildCardCount2 + bracketCount2;
if (totalCount1 != totalCount2) {
return totalCount1 - totalCount2;
}
int pattern1Length = getPatternLength(pattern1);
int pattern2Length = getPatternLength(pattern2);
if (pattern1Length != pattern2Length) {
return pattern2Length - pattern1Length;
}
if (wildCardCount1 < wildCardCount2) {
return -1;
}
else if (wildCardCount2 < wildCardCount1) {
return 1;
}
if (bracketCount1 < bracketCount2) {
return -1;
}
else if (bracketCount2 < bracketCount1) {
return 1;
}
return 0;
}
private int getWildCardCount(String pattern) {
if (pattern.endsWith(".*")) {
pattern = pattern.substring(0, pattern.length() - 2);
}
return countOccurrencesOf(pattern, "*");
}
/**
* Returns the length of the given pattern, where template variables are considered to be 1 long.
*/
private int getPatternLength(String pattern) {
Matcher m = VARIABLE_PATTERN.matcher(pattern);
return m.replaceAll("#").length();
}
}
/**
* Tests whether or not a string matches against a pattern via a {@link Pattern}.
* <p>The pattern may contain special characters: '*' means zero or more characters; '?' means one and
* only one character; '{' and '}' indicate a URI template pattern. For example <tt>/users/{user}</tt>.
*/
private static class AntPathStringMatcher {
private static final Pattern GLOB_PATTERN = Pattern.compile("\\?|\\*|\\{((?:\\{[^/]+?\\}|[^/{}]|\\\\[{}])+?)\\}");
private static final String DEFAULT_VARIABLE_PATTERN = "(.*)";
private final Pattern pattern;
private final List<String> variableNames = new LinkedList<String>();
public AntPathStringMatcher(String pattern) {
StringBuilder patternBuilder = new StringBuilder();
Matcher m = GLOB_PATTERN.matcher(pattern);
int end = 0;
while (m.find()) {
patternBuilder.append(quote(pattern, end, m.start()));
String match = m.group();
if ("?".equals(match)) {
patternBuilder.append('.');
}
else if ("*".equals(match)) {
patternBuilder.append(".*");
}
else if (match.startsWith("{") && match.endsWith("}")) {
int colonIdx = match.indexOf(':');
if (colonIdx == -1) {
patternBuilder.append(DEFAULT_VARIABLE_PATTERN);
this.variableNames.add(m.group(1));
}
else {
String variablePattern = match.substring(colonIdx + 1, match.length() - 1);
patternBuilder.append('(');
patternBuilder.append(variablePattern);
patternBuilder.append(')');
String variableName = match.substring(1, colonIdx);
this.variableNames.add(variableName);
}
}
end = m.end();
}
patternBuilder.append(quote(pattern, end, pattern.length()));
this.pattern = Pattern.compile(patternBuilder.toString());
}
private String quote(String s, int start, int end) {
if (start == end) {
return "";
}
return Pattern.quote(s.substring(start, end));
}
/**
* Main entry point.
* @return {@code true} if the string matches against the pattern, or {@code false} otherwise.
*/
public boolean matchStrings(String str, Map<String, String> uriTemplateVariables) {
Matcher matcher = this.pattern.matcher(str);
if (matcher.matches()) {
if (uriTemplateVariables != null) {
if (this.variableNames.size() != matcher.groupCount()) {
throw new IllegalArgumentException("The number of capturing groups in the pattern segment " + this.pattern +
" does not match the number of URI template variables it defines, which can occur if " +
" capturing groups are used in a URI template regex. Use non-capturing groups instead.");
}
for (int i = 1; i <= matcher.groupCount(); i++) {
String name = this.variableNames.get(i - 1);
String value = matcher.group(i);
uriTemplateVariables.put(name, value);
}
}
return true;
}
else {
return false;
}
}
}
/**
* Tokenize the given String into a String array via a StringTokenizer.
* <p>The given delimiters string is supposed to consist of any number of
* delimiter characters. Each of those characters can be used to separate
* tokens. A delimiter is always a single character; for multi-character
* delimiters, consider using {@code delimitedListToStringArray}
* @param str the String to tokenize
* @param delimiters the delimiter characters, assembled as String
* (each of those characters is individually considered as delimiter)
* @param trimTokens trim the tokens via String's {@code trim}
* @param ignoreEmptyTokens omit empty tokens from the result array
* (only applies to tokens that are empty after trimming; StringTokenizer
* will not consider subsequent delimiters as token in the first place).
* @return an array of the tokens ({@code null} if the input String
* was {@code null})
* @see java.util.StringTokenizer
* @see String#trim()
* @see #delimitedListToStringArray
*/
private static String[] tokenizeToStringArray(
String str, String delimiters, boolean trimTokens, boolean ignoreEmptyTokens) {
if (str == null) {
return null;
}
StringTokenizer st = new StringTokenizer(str, delimiters);
List<String> tokens = new ArrayList<String>();
while (st.hasMoreTokens()) {
String token = st.nextToken();
if (trimTokens) {
token = token.trim();
}
if (!ignoreEmptyTokens || token.length() > 0) {
tokens.add(token);
}
}
return toStringArray(tokens);
}
/**
* Copy the given Collection into a String array.
* The Collection must contain String elements only.
* @param collection the Collection to copy
* @return the String array ({@code null} if the passed-in
* Collection was {@code null})
*/
private static String[] toStringArray(Collection<String> collection) {
if (collection == null) {
return null;
}
return collection.toArray(new String[collection.size()]);
}
/**
* Check that the given CharSequence is neither {@code null} nor of length 0.
* Note: Will return {@code true} for a CharSequence that purely consists of whitespace.
* <p><pre>
* StringUtils.hasLength(null) = false
* StringUtils.hasLength("") = false
* StringUtils.hasLength(" ") = true
* StringUtils.hasLength("Hello") = true
* </pre>
* @param str the CharSequence to check (may be {@code null})
* @return {@code true} if the CharSequence is not null and has length
* @see #hasText(String)
*/
private static boolean hasLength(CharSequence str) {
return (str != null && str.length() > 0);
}
/**
* Check whether the given CharSequence has actual text.
* More specifically, returns {@code true} if the string not {@code null},
* its length is greater than 0, and it contains at least one non-whitespace character.
* <p><pre>
* StringUtils.hasText(null) = false
* StringUtils.hasText("") = false
* StringUtils.hasText(" ") = false
* StringUtils.hasText("12345") = true
* StringUtils.hasText(" 12345 ") = true
* </pre>
* @param str the CharSequence to check (may be {@code null})
* @return {@code true} if the CharSequence is not {@code null},
* its length is greater than 0, and it does not contain whitespace only
* @see Character#isWhitespace
*/
private static boolean hasText(CharSequence str) {
if (!hasLength(str)) {
return false;
}
int strLen = str.length();
for (int i = 0; i < strLen; i++) {
if (!Character.isWhitespace(str.charAt(i))) {
return true;
}
}
return false;
}
/**
* Check whether the given String has actual text.
* More specifically, returns {@code true} if the string not {@code null},
* its length is greater than 0, and it contains at least one non-whitespace character.
* @param str the String to check (may be {@code null})
* @return {@code true} if the String is not {@code null}, its length is
* greater than 0, and it does not contain whitespace only
* @see #hasText(CharSequence)
*/
private static boolean hasText(String str) {
return hasText((CharSequence) str);
}
/**
* Count the occurrences of the substring in string s.
* @param str string to search in. Return 0 if this is null.
* @param sub string to search for. Return 0 if this is null.
*/
private static int countOccurrencesOf(String str, String sub) {
if (str == null || sub == null || str.length() == 0 || sub.length() == 0) {
return 0;
}
int count = 0;
int pos = 0;
int idx;
while ((idx = str.indexOf(sub, pos)) != -1) {
++count;
pos = idx + sub.length();
}
return count;
}
class SeekerIterator implements Iterator<File> {
final String pattern;
SeekState stack;
File next;
StringBuffer buffer = new StringBuffer();
public SeekerIterator(File root, String spath, String pattern) {
this.pattern = pattern;
buffer.append(spath);
stack = new SeekState();
File[] files = root.listFiles();
if (files != null) {
stack.files.addAll(Arrays.asList(files));
}
stack.pathLength = buffer.length();
seek();
}
@Override
public boolean hasNext() {
return next != null;
}
@Override
public File next() {
if (next == null) {
throw new NoSuchElementException();
}
File n = next;
seek();
return n;
}
@Override
public void remove() {
throw new UnsupportedOperationException();
}
private void seek() {
next = null;
while(stack != null) {
if (stack.files.isEmpty()) {
stack = stack.prev;
continue;
}
File file = stack.files.remove(0);
buffer.setLength(stack.pathLength);
buffer.append(pathSeparator);
buffer.append(file.getName());
String path = buffer.toString();
if (file.isDirectory() && matchStart(pattern, path)) {
SeekState nstate = new SeekState();
nstate.pathLength = buffer.length();
nstate.node = file;
nstate.prev = stack;
nstate.files.addAll(Arrays.asList(file.listFiles()));
stack = nstate;
}
if (match(pattern, path)) {
next = file;
break;
}
}
}
}
static class SeekState {
File node;
SeekState prev;
List<File> files = new ArrayList<File>();
int pathLength;
}
}