package com.fasterxml.jackson.core.util;

import java.io.*;
import java.util.Properties;
import java.util.regex.Pattern;

import com.fasterxml.jackson.core.Version;
import com.fasterxml.jackson.core.Versioned;

Functionality for supporting exposing of component Versions. Also contains other misc methods that have no other place to live in.

Note that this class can be used in two roles: first, as a static utility class for loading purposes, and second, as a singleton loader of per-module version information.

Note that method for accessing version information changed between versions 2.1 and 2.2; earlier code used file named "VERSION.txt"; but this has serious performance issues on some platforms (Android), so a replacement system was implemented to use class generation and dynamic class loading.

Note that functionality for reading "VERSION.txt" was removed completely from Jackson 2.6.

/** * Functionality for supporting exposing of component {@link Version}s. * Also contains other misc methods that have no other place to live in. *<p> * Note that this class can be used in two roles: first, as a static * utility class for loading purposes, and second, as a singleton * loader of per-module version information. *<p> * Note that method for accessing version information changed between versions * 2.1 and 2.2; earlier code used file named "VERSION.txt"; but this has serious * performance issues on some platforms (Android), so a replacement system * was implemented to use class generation and dynamic class loading. *<p> * Note that functionality for reading "VERSION.txt" was removed completely * from Jackson 2.6. */
public class VersionUtil { private final static Pattern V_SEP = Pattern.compile("[-_./;:]"); /* /********************************************************************** /* Instance life-cycle /********************************************************************** */ protected VersionUtil() { } @Deprecated // since 2.9 public Version version() { return Version.unknownVersion(); } /* /********************************************************************** /* Static load methods /********************************************************************** */
Loads version information by introspecting a class named "PackageVersion" in the same package as the given class.

If the class could not be found or does not have a public static Version field named "VERSION", returns "empty" Version returned by Version.unknownVersion().

Params:
  • cls – Class for which to look version information
Returns:Version information discovered if any; Version.unknownVersion() if none
/** * Loads version information by introspecting a class named * "PackageVersion" in the same package as the given class. *<p> * If the class could not be found or does not have a public * static Version field named "VERSION", returns "empty" {@link Version} * returned by {@link Version#unknownVersion()}. * * @param cls Class for which to look version information * * @return Version information discovered if any; * {@link Version#unknownVersion()} if none */
public static Version versionFor(Class<?> cls) { Version v = null; try { String versionInfoClassName = cls.getPackage().getName() + ".PackageVersion"; Class<?> vClass = Class.forName(versionInfoClassName, true, cls.getClassLoader()); // However, if class exists, it better work correctly, no swallowing exceptions try { v = ((Versioned) vClass.getDeclaredConstructor().newInstance()).version(); } catch (Exception e) { throw new IllegalArgumentException("Failed to get Versioned out of "+vClass); } } catch (Exception e) { // ok to be missing (not good but acceptable) ; } return (v == null) ? Version.unknownVersion() : v; }
Params:
  • cls – Class for which to look version information
Returns:Version information discovered if any; Version.unknownVersion() if none
Deprecated:Since 2.12 simply use versionFor(Class<?>) instead
/** * Alias of {@link #versionFor(Class)}. * * @param cls Class for which to look version information * * @return Version information discovered if any; * {@link Version#unknownVersion()} if none * * @deprecated Since 2.12 simply use {@link #versionFor(Class)} instead */
@Deprecated public static Version packageVersionFor(Class<?> cls) { return versionFor(cls); }
Will attempt to load the maven version for the given groupId and artifactId. Maven puts a pom.properties file in META-INF/maven/groupId/artifactId, containing the groupId, artifactId and version of the library.
Params:
  • cl – the ClassLoader to load the pom.properties file from
  • groupId – the groupId of the library
  • artifactId – the artifactId of the library
Returns:The version
Deprecated:Since 2.6: functionality not used by any official Jackson component, should be moved out if anyone needs it
/** * Will attempt to load the maven version for the given groupId and * artifactId. Maven puts a pom.properties file in * META-INF/maven/groupId/artifactId, containing the groupId, * artifactId and version of the library. * * @param cl the ClassLoader to load the pom.properties file from * @param groupId the groupId of the library * @param artifactId the artifactId of the library * @return The version * * @deprecated Since 2.6: functionality not used by any official Jackson component, should be * moved out if anyone needs it */
@SuppressWarnings("resource") @Deprecated // since 2.6 public static Version mavenVersionFor(ClassLoader cl, String groupId, String artifactId) { InputStream pomProperties = cl.getResourceAsStream("META-INF/maven/" + groupId.replaceAll("\\.", "/")+ "/" + artifactId + "/pom.properties"); if (pomProperties != null) { try { Properties props = new Properties(); props.load(pomProperties); String versionStr = props.getProperty("version"); String pomPropertiesArtifactId = props.getProperty("artifactId"); String pomPropertiesGroupId = props.getProperty("groupId"); return parseVersion(versionStr, pomPropertiesGroupId, pomPropertiesArtifactId); } catch (IOException e) { // Ignore } finally { _close(pomProperties); } } return Version.unknownVersion(); }
Method used by PackageVersion classes to decode version injected by Maven build.
Params:
  • s – Version String to parse
  • groupId – Maven group id to include with version
  • artifactId – Maven artifact id to include with version
Returns:Version instance constructed from parsed components, if successful; Version.unknownVersion() if parsing of components fail
/** * Method used by <code>PackageVersion</code> classes to decode version injected by Maven build. * * @param s Version String to parse * @param groupId Maven group id to include with version * @param artifactId Maven artifact id to include with version * * @return Version instance constructed from parsed components, if successful; * {@link Version#unknownVersion()} if parsing of components fail */
public static Version parseVersion(String s, String groupId, String artifactId) { if (s != null && (s = s.trim()).length() > 0) { String[] parts = V_SEP.split(s); return new Version(parseVersionPart(parts[0]), (parts.length > 1) ? parseVersionPart(parts[1]) : 0, (parts.length > 2) ? parseVersionPart(parts[2]) : 0, (parts.length > 3) ? parts[3] : null, groupId, artifactId); } return Version.unknownVersion(); } protected static int parseVersionPart(String s) { int number = 0; for (int i = 0, len = s.length(); i < len; ++i) { char c = s.charAt(i); if (c > '9' || c < '0') break; number = (number * 10) + (c - '0'); } return number; } private final static void _close(Closeable c) { try { c.close(); } catch (IOException e) { } } /* /********************************************************************** /* Orphan utility methods /********************************************************************** */ public final static void throwInternal() { throw new RuntimeException("Internal error: this code path should never get executed"); } }