Java tutorial
/* Copyright 2016 The Trustees of University of Arizona 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 hsyndicate.fs; import java.net.URI; import java.net.URISyntaxException; import java.util.ArrayList; import java.util.List; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; public class SyndicateFSPath implements Comparable { private static final Log LOG = LogFactory.getLog(SyndicateFSPath.class); // stores path hierarchy private URI uri; /* * Construct a path from parent/child pairs */ public SyndicateFSPath(String parent, String child) { this(new SyndicateFSPath(parent), new SyndicateFSPath(child)); } public SyndicateFSPath(SyndicateFSPath parent, String child) { this(parent, new SyndicateFSPath(child)); } public SyndicateFSPath(String parent, SyndicateFSPath child) { this(new SyndicateFSPath(parent), child); } public SyndicateFSPath(SyndicateFSPath parent, SyndicateFSPath child) { if (parent == null) throw new IllegalArgumentException("Can not resolve a path from a null parent"); if (child == null) throw new IllegalArgumentException("Can not resolve a path from a null child"); URI parentUri = parent.uri; if (parentUri == null) throw new IllegalArgumentException("Can not resolve a path from a null parent URI"); String parentPath = parentUri.getPath(); if (!(parentPath.equals("/") || parentPath.equals(""))) { // parent path is not empty -- need to parse try { parentUri = new URI(parentUri.getScheme(), parentUri.getAuthority(), parentUri.getPath() + "/", null, parentUri.getFragment()); } catch (URISyntaxException e) { throw new IllegalArgumentException(e); } } URI resolved = parentUri.resolve(child.uri); // assign resolved uri to member field this.uri = createPathUri(resolved.getScheme(), resolved.getAuthority(), normalizePath(resolved.getPath())); //LOG.info("path - " + uri.toString()); } /* * Construct a path from string */ public SyndicateFSPath(String path) { if (path == null) throw new IllegalArgumentException("Can not create a path from a null string"); if (path.length() == 0) throw new IllegalArgumentException("Can not create a path from an empty string"); String uriScheme = null; String uriAuthority = null; String uriPath = null; int start = 0; // parse uri scheme int colon = path.indexOf(':'); if (colon != -1) { uriScheme = path.substring(0, colon); start = colon + 1; // parse uri authority if (path.startsWith("//", start) && (path.length() - start > 2)) { // have authority int nextSlash = path.indexOf('/', start + 2); int authEnd; if (nextSlash != -1) authEnd = nextSlash; else authEnd = path.length(); uriAuthority = path.substring(start + 2, authEnd); start = authEnd; } } // uri path if (start < path.length()) uriPath = path.substring(start, path.length()); // assign resolved uri to member field this.uri = createPathUri(uriScheme, uriAuthority, uriPath); //LOG.info("path - " + uri.toString()); } /* * Construct a path from URI */ public SyndicateFSPath(URI uri) { this.uri = uri; //LOG.info("path - " + uri.toString()); } private URI createPathUri(String scheme, String authority, String path) { try { URI uri = new URI(scheme, authority, normalizePath(path), null, null); return uri.normalize(); } catch (URISyntaxException e) { throw new IllegalArgumentException(e); } } private String normalizePath(String path) { // replace all "//" and "\" to "/" path = path.replace("//", "/"); path = path.replace("\\", "/"); // trim trailing slash if (path.length() > 1 && path.endsWith("/")) { path = path.substring(0, path.length() - 1); } return path; } /* * Return URI formatted path */ public URI toUri() { return this.uri; } /* * True if the path is absolute */ public boolean isAbsolute() { return this.uri.getPath().startsWith("/"); } /* * Return file name */ public String getName() { String path = this.uri.getPath(); int slash = path.lastIndexOf('/'); return path.substring(slash + 1, path.length()); } public String getSessionName() { String path = this.uri.getPath(); // empty if (path.length() == 0) { return null; } // root if (path.length() == 1 && path.equals("/")) { return null; } if (path.startsWith("/")) { int secondSlash = path.indexOf('/', 1); if (secondSlash == -1) { return path.substring(1); } else { return path.substring(1, secondSlash); } } else { return null; } } public String getPathWithoutSession() { String path = this.uri.getPath(); // empty if (path.length() == 0) { return null; } // root if (path.length() == 1 && path.equals("/")) { return null; } if (path.startsWith("/")) { int secondSlash = path.indexOf('/', 1); if (secondSlash == -1) { return new String(); } else { return path.substring(secondSlash); } } else { return null; } } /* * Return the parent path, Null if parent is root */ public SyndicateFSPath getParent() { String path = this.uri.getPath(); int lastSlash = path.lastIndexOf('/'); // empty if (path.length() == 0) { return null; } // root if (path.length() == 1 && lastSlash == 0) { return null; } if (lastSlash == -1) { return new SyndicateFSPath(createPathUri(this.uri.getScheme(), this.uri.getAuthority(), ".")); } else if (lastSlash == 0) { return new SyndicateFSPath(createPathUri(this.uri.getScheme(), this.uri.getAuthority(), "/")); } else { String parent = path.substring(0, lastSlash); return new SyndicateFSPath(createPathUri(this.uri.getScheme(), this.uri.getAuthority(), parent)); } } /* * Return the stringfied path that contains scheme, authority and path */ @Override public String toString() { StringBuilder sb = new StringBuilder(); if (this.uri.getScheme() != null) { sb.append(this.uri.getScheme()); sb.append(":"); } if (this.uri.getAuthority() != null) { sb.append("//"); sb.append(this.uri.getAuthority()); } if (this.uri.getPath() != null) { String path = this.uri.getPath(); sb.append(path); } return sb.toString(); } /* * Return the stringfied path that does not contains scheme and authority */ public String getPath() { if (this.uri.getPath() != null) { return uri.getPath(); } return new String(); } public int depth() { String path = this.uri.getPath(); if (path.length() == 1 && path.startsWith("/")) return 0; int depth = 0; int slash = 0; while (slash != -1) { // slash starts from 1 slash = path.indexOf("/", slash + 1); depth++; } return depth; } public SyndicateFSPath[] getAncestors() { List<SyndicateFSPath> ancestors = new ArrayList<SyndicateFSPath>(); SyndicateFSPath parent = getParent(); while (parent != null) { ancestors.add(0, parent); parent = parent.getParent(); } SyndicateFSPath[] ancestorsArray = ancestors.toArray(new SyndicateFSPath[0]); return ancestorsArray; } public SyndicateFSPath suffix(String suffix) { return new SyndicateFSPath(getPath() + suffix); } @Override public boolean equals(Object o) { if (!(o instanceof SyndicateFSPath)) return false; SyndicateFSPath other = (SyndicateFSPath) o; return this.uri.equals(other.uri); } @Override public int hashCode() { return this.uri.hashCode(); } @Override public int compareTo(Object o) { SyndicateFSPath other = (SyndicateFSPath) o; return this.uri.compareTo(other.uri); } }