1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/main/java/de/uapcore/lightpit/PathPattern.java Thu Oct 15 18:36:05 2020 +0200
1.3 @@ -0,0 +1,125 @@
1.4 +package de.uapcore.lightpit;
1.5 +
1.6 +import java.util.ArrayList;
1.7 +import java.util.List;
1.8 +
1.9 +public final class PathPattern {
1.10 +
1.11 + private final List<String> nodePatterns;
1.12 + private final boolean collection;
1.13 +
1.14 + /**
1.15 + * Constructs a new path pattern.
1.16 + * The special directories . and .. are disallowed in the pattern.
1.17 + *
1.18 + * @param pattern
1.19 + */
1.20 + public PathPattern(String pattern) {
1.21 + nodePatterns = parse(pattern);
1.22 + collection = pattern.endsWith("/");
1.23 + }
1.24 +
1.25 + private List<String> parse(String pattern) {
1.26 +
1.27 + var nodes = new ArrayList<String>();
1.28 + var parts = pattern.split("/");
1.29 +
1.30 + for (var part : parts) {
1.31 + if (part.isBlank()) continue;
1.32 + if (part.equals(".") || part.equals(".."))
1.33 + throw new IllegalArgumentException("Path must not contain '.' or '..' nodes.");
1.34 + nodes.add(part);
1.35 + }
1.36 +
1.37 + return nodes;
1.38 + }
1.39 +
1.40 + /**
1.41 + * Matches a path against this pattern.
1.42 + * The path must be canonical in the sense that no . or .. parts occur.
1.43 + *
1.44 + * @param path the path to match
1.45 + * @return true if the path matches the pattern, false otherwise
1.46 + */
1.47 + public boolean matches(String path) {
1.48 + if (collection ^ path.endsWith("/"))
1.49 + return false;
1.50 +
1.51 + var nodes = parse(path);
1.52 + if (nodePatterns.size() != nodes.size())
1.53 + return false;
1.54 +
1.55 + for (int i = 0 ; i < nodePatterns.size() ; i++) {
1.56 + var pattern = nodePatterns.get(i);
1.57 + var node = nodes.get(i);
1.58 + if (pattern.startsWith("$"))
1.59 + continue;
1.60 + if (!pattern.equals(node))
1.61 + return false;
1.62 + }
1.63 +
1.64 + return true;
1.65 + }
1.66 +
1.67 + /**
1.68 + * Returns the path parameters found in the specified path using this pattern.
1.69 + * The return value of this method is undefined, if the patter does not match.
1.70 + *
1.71 + * @param path the path
1.72 + * @return the path parameters, if any, or an empty map
1.73 + * @see #matches(String)
1.74 + */
1.75 + public PathParameters obtainPathParameters(String path) {
1.76 + var params = new PathParameters();
1.77 +
1.78 + var nodes = parse(path);
1.79 +
1.80 + for (int i = 0 ; i < Math.min(nodes.size(), nodePatterns.size()) ; i++) {
1.81 + var pattern = nodePatterns.get(i);
1.82 + var node = nodes.get(i);
1.83 + if (pattern.startsWith("$")) {
1.84 + params.put(pattern.substring(1), node);
1.85 + }
1.86 + }
1.87 +
1.88 + return params;
1.89 + }
1.90 +
1.91 + @Override
1.92 + public int hashCode() {
1.93 + var str = new StringBuilder();
1.94 + for (var node : nodePatterns) {
1.95 + if (node.startsWith("$")) {
1.96 + str.append("/$");
1.97 + } else {
1.98 + str.append('/');
1.99 + str.append(node);
1.100 + }
1.101 + }
1.102 + if (collection)
1.103 + str.append('/');
1.104 +
1.105 + return str.toString().hashCode();
1.106 + }
1.107 +
1.108 + @Override
1.109 + public boolean equals(Object obj) {
1.110 + if (!obj.getClass().equals(PathPattern.class))
1.111 + return false;
1.112 +
1.113 + var other = (PathPattern) obj;
1.114 + if (collection ^ other.collection || nodePatterns.size() != other.nodePatterns.size())
1.115 + return false;
1.116 +
1.117 + for (int i = 0 ; i < nodePatterns.size() ; i++) {
1.118 + var left = nodePatterns.get(i);
1.119 + var right = other.nodePatterns.get(i);
1.120 + if (left.startsWith("$") && right.startsWith("$"))
1.121 + continue;
1.122 + if (!left.equals(right))
1.123 + return false;
1.124 + }
1.125 +
1.126 + return true;
1.127 + }
1.128 +}
