我正在按照Servlet规范实现 Servlet URL模式匹配。我的匹配方法：
public static boolean match(String pattern, String str, boolean isCaseSensitive) {
char[] patArr = pattern.toCharArray();
char[] strArr = str.toCharArray();
int patIdxStart = 0;
int patIdxEnd = patArr.length - 1;
int strIdxStart = 0;
int strIdxEnd = strArr.length - 1;
boolean containsStar = false;
for (int i = 0; i < patArr.length; i++) {
if (patArr[i] != '*') {
continue;
}
containsStar = true;
break;
}
if (!containsStar) {
if (patIdxEnd != strIdxEnd) {
return false;
}
for (int i = 0; i <= patIdxEnd; i++) {
char ch = patArr[i];
if (ch == '?')
continue;
if ((isCaseSensitive) && (ch != strArr[i])) {
return false;
}
if ((!isCaseSensitive)
&& (Character.toUpperCase(ch) != Character
.toUpperCase(strArr[i]))) {
return false;
}
}
return true;
}
if (patIdxEnd == 0) {
return true;
}
char ch;
while (((ch = patArr[patIdxStart]) != '*')
&& (strIdxStart <= strIdxEnd)) {
if (ch != '?') {
if ((isCaseSensitive) && (ch != strArr[strIdxStart])) {
return false;
}
if ((!isCaseSensitive)
&& (Character.toUpperCase(ch) != Character
.toUpperCase(strArr[strIdxStart]))) {
return false;
}
}
patIdxStart++;
strIdxStart++;
}
if (strIdxStart > strIdxEnd) {
for (int i = patIdxStart; i <= patIdxEnd; i++) {
if (patArr[i] != '*') {
return false;
}
}
return true;
}
while (((ch = patArr[patIdxEnd]) != '*') && (strIdxStart <= strIdxEnd)) {
if (ch != '?') {
if ((isCaseSensitive) && (ch != strArr[strIdxEnd])) {
return false;
}
if ((!isCaseSensitive)
&& (Character.toUpperCase(ch) != Character
.toUpperCase(strArr[strIdxEnd]))) {
return false;
}
}
patIdxEnd--;
strIdxEnd--;
}
if (strIdxStart > strIdxEnd) {
for (int i = patIdxStart; i <= patIdxEnd; i++) {
if (patArr[i] != '*') {
return false;
}
}
return true;
}
while ((patIdxStart != patIdxEnd) && (strIdxStart <= strIdxEnd)) {
int patIdxTmp = -1;
for (int i = patIdxStart + 1; i <= patIdxEnd; i++) {
if (patArr[i] != '*') {
continue;
}
patIdxTmp = i;
break;
}
if (patIdxTmp == patIdxStart + 1) {
patIdxStart++;
continue;
}
int patLength = patIdxTmp - patIdxStart - 1;
int strLength = strIdxEnd - strIdxStart + 1;
int foundIdx = -1;
for (int i = 0; i <= strLength - patLength; i++) {
int j = 0;
while (true)
if (j < patLength) {
ch = patArr[(patIdxStart + j + 1)];
if (ch != '?') {
if ((isCaseSensitive)
&& (ch != strArr[(strIdxStart + i + j)])) {
break;
}
if ((!isCaseSensitive)
&& (Character.toUpperCase(ch) != Character
.toUpperCase(strArr[(strIdxStart
+ i + j)])))
break;
} else {
j++;
continue;
}
} else {
foundIdx = strIdxStart + i;
break;
}
}
if (foundIdx == -1) {
return false;
}
patIdxStart = patIdxTmp;
strIdxStart = foundIdx + patLength;
}
for (int i = patIdxStart; i <= patIdxEnd; i++) {
if (patArr[i] != '*') {
return false;
}
}
return true;
}
但是当我用下面的案例进行测试时：
String pattern = "*.a*";
String path = "/index.abc";
String matches = match(pattern, path, true) ? "matches" : "unmatches";
System.out.println(path + " " + matches + " " + pattern);
测试用例永远运行，无法停止。我有两个问题：
"*.a*"是否与Servlet URL模式匹配规范有效？ 答案 0 :(得分：1)
这是我的Java Servlet规范3。1（2013年4月）将请求映射到Servlets的实现。
/**
* Java Servlet Specification 3.1 (April 2013)
* Mapping Requests to Servlets (Chapter 12) implementation.
*
* This class is thread safe.
*/
public class ServletMappingMatcher {
private final String[] patterns;
private final String[] welcomePages;
public ServletMappingMatcher(String... patterns) {
this(patterns, new String[0]);
}
public ServletMappingMatcher(String[] patterns, String[] welcomePages) {
this.patterns = patterns;
this.welcomePages = welcomePages;
}
public String getPatternForPath(String path) {
for (String pattern : patterns) {
if (matches(pattern, path)) {
return pattern;
}
}
return null;
}
private boolean matches(String pattern, String path) {
if (isPathMapping(pattern)) {
return pathMatches(pattern, path);
} else if (isExtensionPattern(pattern)) {
return extensionMatches(pattern, path);
} else if (isApplicationContextRoot(pattern)) {
return matchesApplicationContextRoot(path);
} else if (isDefaultServlet(pattern)) {
return matchesDefaultServlet(path);
}
return strictlyMatches(pattern, path);
}
private boolean isPathMapping(String pattern) {
return pattern.startsWith("/") && pattern.endsWith("/*");
}
private boolean isExtensionPattern(String pattern) {
return pattern.startsWith("*.");
}
private boolean isApplicationContextRoot(String pattern) {
return pattern.isEmpty();
}
private boolean isDefaultServlet(String pattern) {
return pattern.equals("/");
}
private boolean pathMatches(String pattern, String path) {
return path.startsWith(pattern.substring(0, pattern.length() - 1)) ||
path.equals(pattern.substring(0, pattern.length() - 2));
}
private boolean extensionMatches(String pattern, String path) {
return path.endsWith(pattern.substring(1));
}
private boolean matchesApplicationContextRoot(String path) {
return path.equals("/");
}
private boolean strictlyMatches(String pattern, String path) {
return path.equals(pattern);
}
private boolean matchesDefaultServlet(String path) {
if (path.endsWith("/")) {
return true;
}
for (String welcomePage : welcomePages) {
if (path.endsWith("/" + welcomePage)) {
return true;
}
}
return false;
}
}
JUnit测试：
import org.junit.Assert;
import org.junit.Test;
public class ServletMappingMatcherTest {
@Test
public void testsFromSpec() {
final String servlet1Pattern = "/foo/bar/*";
final String servlet2Pattern = "/baz/*";
final String servlet3Pattern = "/catalog";
final String servlet4Pattern = "*.bop";
final String defaultServlet = "/";
final String[] patterns = {servlet1Pattern, servlet2Pattern, servlet3Pattern, servlet4Pattern, defaultServlet};
final String[] welcomePages = {"index.html"};
final ServletMappingMatcher matcher = new ServletMappingMatcher(patterns, welcomePages);
Assert.assertEquals(servlet1Pattern, matcher.getPatternForPath("/foo/bar/index.html"));
Assert.assertEquals(servlet1Pattern, matcher.getPatternForPath("/foo/bar/index.bop"));
Assert.assertEquals(servlet2Pattern, matcher.getPatternForPath("/baz"));
Assert.assertEquals(servlet2Pattern, matcher.getPatternForPath("/baz/index.html"));
Assert.assertEquals(servlet3Pattern, matcher.getPatternForPath("/catalog"));
Assert.assertEquals(defaultServlet, matcher.getPatternForPath("/catalog/index.html"));
Assert.assertEquals(servlet4Pattern, matcher.getPatternForPath("/catalog/rececar.bop"));
Assert.assertEquals(servlet4Pattern, matcher.getPatternForPath("/index.bop"));
}
}
答案 1 :(得分：0)
我修复了它，在while（true）循环中添加以下行来打破循环：
[...]
while(true) {
if (ch != '?') {
if(...) {
//...
break;
}
if(...) {
//...
break;
}
j++; // Add this line to avoid infinite loop
}
}