RelativizesFilePaths.java
package com.github.searls.jasmine.io;
import org.apache.commons.lang3.StringEscapeUtils;
import org.apache.commons.lang3.StringUtils;
import java.io.File;
import java.io.IOException;
public class RelativizesFilePaths {
public String relativize(File from, File to) throws IOException {
String fromPath = from.getCanonicalPath();
String toPath = to.getCanonicalPath();
String root = StringUtils.getCommonPrefix(new String[]{fromPath, toPath});
StringBuffer result = new StringBuffer();
if (this.fromPathIsNotADirectAncestor(fromPath, root)) {
for (@SuppressWarnings("unused") String dir : this.divergentDirectories(root, fromPath)) {
result.append("..").append(File.separator);
}
}
result.append(this.pathAfterRoot(toPath, root));
return this.convertSlashes(this.trimLeadingSlashIfNecessary(result));
}
private String convertSlashes(String path) {
return path.replace(File.separatorChar, '/');
}
private boolean fromPathIsNotADirectAncestor(String fromPath, String root) {
return !StringUtils.equals(root, fromPath);
}
private String[] divergentDirectories(String root, String fullPath) {
return this.pathAfterRoot(fullPath, root).split(StringEscapeUtils.escapeJava(File.separator));
}
private String pathAfterRoot(String path, String root) {
return StringUtils.substringAfterLast(path, root);
}
private String trimLeadingSlashIfNecessary(StringBuffer result) {
return StringUtils.removeStart(result.toString(), File.separator);
}
}