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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 {@link Version}s.
 * 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. */ public class VersionUtil { private final static Pattern V_SEP = Pattern.compile("[-_./;:]"); private final Version _v; /* /********************************************************** /* Instance life-cycle /********************************************************** */ protected VersionUtil() { Version v = null; try { /* Class we pass only matters for resource-loading: can't use this Class * (as it's just being loaded at this point), nor anything that depends on it. */ v = VersionUtil.versionFor(getClass()); } catch (Exception e) { // not good to dump to stderr; but that's all we have at this low level System.err.println("ERROR: Failed to load Version information from "+getClass()); } if (v == null) { v = Version.unknownVersion(); } _v = v; } public Version version() { return _v; } /* /********************************************************** /* Static load methods /********************************************************** */ /** * Helper method that will try to load version information for specified * class. Implementation is as follows: * * First, tries to load version info from a class named * "PackageVersion" in the same package as the class. * * Next, if that fails, class loader that loaded specified class is * asked to load resource with name "VERSION" from same location * (package) as class itself had. * * If no version information is found, {@link Version#unknownVersion()} is returned. */ @SuppressWarnings("resource") public static Version versionFor(Class cls) { Version packageVersion = packageVersionFor(cls); if (packageVersion != null) { return packageVersion; } final InputStream in = cls.getResourceAsStream("VERSION.txt"); if (in == null) { return Version.unknownVersion(); } try { InputStreamReader reader = new InputStreamReader(in, "UTF-8"); return doReadVersion(reader); } catch (UnsupportedEncodingException e) { return Version.unknownVersion(); } finally { _close(in); } } /** * 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 null. */ public static Version packageVersionFor(Class cls) { 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 { return ((Versioned) vClass.newInstance()).version(); } catch (Exception e) { throw new IllegalArgumentException("Failed to get Versioned out of "+vClass); } } catch (Exception e) { // ok to be missing (not good, acceptable) return null; } } private static Version doReadVersion(final Reader r) { String version = null, group = null, artifact = null; final BufferedReader br = new BufferedReader(r); try { version = br.readLine(); if (version != null) { group = br.readLine(); if (group != null) { artifact = br.readLine(); } } } catch (IOException ignored) { } finally { _close(br); } // We don't trim() version: parseVersion() takes care ot that if (group != null) { group = group.trim(); } if (artifact != null) { artifact = artifact.trim(); } return parseVersion(version, group, artifact); } /** * 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 */ @SuppressWarnings("resource") 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(); } 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 null; } 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"); } }





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