org.hl7.fhir.utilities.PathBuilder Maven / Gradle / Ivy
package org.hl7.fhir.utilities;
import java.io.File;
import java.io.IOException;
import java.nio.file.Path;
import java.nio.file.Paths;
import org.hl7.fhir.utilities.filesystem.ManagedFileAccess;
import org.hl7.fhir.utilities.settings.FhirSettings;
import lombok.AccessLevel;
import lombok.AllArgsConstructor;
import lombok.With;
@AllArgsConstructor(access = AccessLevel.PRIVATE)
public class PathBuilder {
/**
* By default, the normalized built path must be a child of the first entry of the buildPath arguments. If a
* different parent is desired, this can be set via withRequiredTarget
*/
@With
private final String requiredTarget;
/**
* By default, the first entry of the buildPath argument cannot be null or an empty string. Setting this to false will
* disable this check.
*/
@With
private final boolean requireNonNullNonEmptyFirstEntry;
/**
* By default, the first entry of the buildPath argument cannot be a root directory ("/", "C:\", etc. . Setting this to false will disable this check.
*/
@With
private final boolean requireNonRootFirstEntry;
/**
* By default, the normalized built path must be a child of the first entry of the buildPath arguments. Setting this
* to false will disable this check.
*/
@With
private final boolean requirePathIsChildOfTarget;
/**
* Returns an instance of PathBuilder with all checks enabled (recommended).
*
* @return
*/
public static PathBuilder getPathBuilder() {
return new PathBuilder(null, true, true, true);
}
/**
* Builds a path from the passed argument strings. This path will be compatible with the local filesystem.
*
*
*
* If the args contain variables enclosed in square brackets ([ ]), they will be replaced with values in
* the built path. There are several built-in variables available, listed below. Any text between square brackets that
* does not match these will be replaced by a matching System environment variable if one is available.
*
*
*
* Built-in variables include:
*
* - [tmp] An available temp directory (Java Temp directory,
c:\\temp, $TMPDIR, %TEMP%, etc.)
* - [user] The OS user directory (~, user.home, etc)
*
*
*
*
* This method will run several checks by default to ensure that the built path does not point to unintended areas of
* the filesystem. If these checks are violated, a RuntimeException will be thrown. If needed in special cases, the
* behavior of these checks can be modified via the linked fluent constructor methods below.
*
*
* @param args entries with which to construct the filesystem path
* @throws RuntimeException
* @return a local filesystem path
* @throws IOException
*
* @see this#withRequiredTarget(String)
* @see this#withRequireNonNullNonEmptyFirstEntry(boolean)
* @see this#withRequireNonRootFirstEntry(boolean)
* @see this#withRequirePathIsChildOfTarget(boolean)
*/
public String buildPath(String... args) throws IOException {
checkNonNullNonEmptyFirstEntry(args);
checkNonRootFirstEntry(args);
StringBuilder stringBuilder = new StringBuilder();
boolean argIsNotEmptyOrNull = false;
boolean first = true;
for (String arg : args) {
if (first && arg == null)
continue;
first = false;
if (!argIsNotEmptyOrNull)
argIsNotEmptyOrNull = !Utilities.noString(arg);
else if (!stringBuilder.toString().endsWith(File.separator))
stringBuilder.append(File.separator);
String a = arg;
if (stringBuilder.length() == 0) {
a = replaceVariables(a);
}
a = a.replace("\\", File.separator);
a = a.replace("/", File.separator);
if (stringBuilder.length() > 0 && a.startsWith(File.separator))
a = a.substring(File.separator.length());
while (a.startsWith(".." + File.separator)) {
if (stringBuilder.length() == 0) {
stringBuilder = new StringBuilder(Paths.get(".").toAbsolutePath().normalize().toString());
} else {
String p = stringBuilder.toString().substring(0, stringBuilder.length() - 1);
if (!p.contains(File.separator)) {
stringBuilder = new StringBuilder();
} else {
stringBuilder = new StringBuilder(p.substring(0, p.lastIndexOf(File.separator)) + File.separator);
}
}
a = a.substring(3);
}
if ("..".equals(a)) {
int i = stringBuilder.substring(0, stringBuilder.length() - 1).lastIndexOf(File.separator);
stringBuilder = new StringBuilder(stringBuilder.substring(0, i + 1));
} else
stringBuilder.append(a);
}
checkPathIsChildOfTarget(stringBuilder.toString(), args);
return stringBuilder.toString();
}
private void checkPathIsChildOfTarget(String path, String[] args) throws IOException {
if (!requirePathIsChildOfTarget) {
return;
}
final String target = requiredTarget != null
? requiredTarget
: args[0];
if (!Path.of(path).normalize().startsWith(Path.of(replaceVariables(target)).normalize())) {
throw new RuntimeException("Computed path does not start with first element: " + String.join(", ", args));
}
}
private void checkNonRootFirstEntry(String[] args) {
if (!requireNonRootFirstEntry) {
return;
}
if (isPathRoot(args[0])) {
throw new RuntimeException("First entry in file path cannot be root: " + args[0]+", full path = "+String.join(", ", args));
}
}
private void checkNonNullNonEmptyFirstEntry(String[] args) {
if (!requireNonNullNonEmptyFirstEntry) {
return;
}
if (args[0] == null || Utilities.noString(args[0].trim())) {
throw new RuntimeException("First entry in file path cannot be null or empty, full path = "+String.join(", ", args));
}
}
private String replaceVariables(String a) throws IOException {
if ("[tmp]".equals(a)) {
if (hasCTempDir()) {
return Utilities.C_TEMP_DIR;
} else if (FhirSettings.hasTempPath()) {
return FhirSettings.getTempPath();
} else {
return System.getProperty("java.io.tmpdir");
}
} else if ("[user]".equals(a)) {
return System.getProperty("user.home");
}
return a;
}
protected static boolean hasCTempDir() throws IOException {
if (!System.getProperty("os.name").toLowerCase().contains("win")) {
return false;
}
File tmp = ManagedFileAccess.file(Utilities.C_TEMP_DIR);
return tmp.exists() && tmp.isDirectory() && tmp.canWrite();
}
protected static boolean isPathRoot(String pathString) {
boolean actual;
Path path = Path.of(pathString);
Path normalizedPath = path.normalize();
actual = normalizedPath.equals(path.getRoot());
return actual;
}
}