Fix #10 using build-time metadata.

2 files changed, 75 insertions, 3 deletions

diff --git a/src/main/java/org/anarres/cpp/BuildMetadata.java b/src/main/java/org/anarres/cpp/BuildMetadata.java
new file mode 100644
index 0000000..79de407
--- /dev/null
+++ b/src/main/java/org/anarres/cpp/BuildMetadata.java
@@ -0,0 +1,72 @@
+package org.anarres.cpp;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+import javax.annotation.Nonnull;
+
+/**
+ * Returns information about the build.
+ *
+ * @author shevek
+ */
+public class BuildMetadata {
+
+    public static final String RESOURCE = "/META-INF/jcpp.properties";
+    private static BuildMetadata INSTANCE;
+
+    /** @throws RuntimeException if the properties file cannot be found on the classpath. */
+    @Nonnull
+    public static synchronized BuildMetadata getInstance() {
+        try {
+            if (INSTANCE == null)
+                INSTANCE = new BuildMetadata();
+            return INSTANCE;
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+    }
+
+    private final Properties properties = new Properties();
+
+    private BuildMetadata() throws IOException {
+        URL url = BuildMetadata.class.getResource(RESOURCE);
+        InputStream in = url.openStream();
+        try {
+            properties.load(in);
+        } finally {
+            in.close();
+        }
+    }
+
+    @Nonnull
+    public Map<? extends String, ? extends String> asMap() {
+        Map<String, String> out = new HashMap<String, String>();
+        for (Map.Entry<Object, Object> e : properties.entrySet())
+            out.put(String.valueOf(e.getKey()), String.valueOf(e.getValue()));
+        return out;
+    }
+
+    @Nonnull
+    public com.github.zafarkhaja.semver.Version getVersion() {
+        return com.github.zafarkhaja.semver.Version.valueOf(properties.getProperty("Implementation-Version"));
+    }
+
+    @Nonnull
+    public Date getBuildDate() throws ParseException {
+        // Build-Date=2015-01-01_10:09:09
+        String text = properties.getProperty("Build-Date");
+        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd_HH:mm:ss");
+        return format.parse(text);
+    }
+
+    public String getChangeId() {
+        return properties.getProperty("Change");
+    }
+}
diff --git a/src/main/java/org/anarres/cpp/Main.java b/src/main/java/org/anarres/cpp/Main.java
index 5a3e113..acf2436 100644
--- a/src/main/java/org/anarres/cpp/Main.java
+++ b/src/main/java/org/anarres/cpp/Main.java
@@ -25,7 +25,6 @@ import javax.annotation.Nonnull;
 import joptsimple.OptionParser;
 import joptsimple.OptionSet;
 import joptsimple.OptionSpec;
-import joptsimple.ValueConverter;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -59,7 +58,7 @@ public class Main {
                 "Displays command-line help.")
                 .forHelp();
         OptionSpec<?> versionOption = parser.acceptsAll(Arrays.asList("version"),
-                "Displays the product version (" + Version.getVersion() + ") and exits.")
+                "Displays the product version (" + BuildMetadata.getInstance().getVersion() + ") and exits.")
                 .forHelp();
 
         OptionSpec<?> debugOption = parser.acceptsAll(Arrays.asList("debug"),
@@ -187,7 +186,8 @@ public class Main {
     }
 
     private static void version(@Nonnull PrintStream out) {
-        out.println("Anarres Java C Preprocessor version " + Version.getVersion());
+        BuildMetadata metadata = BuildMetadata.getInstance();
+        out.println("Anarres Java C Preprocessor version " + metadata.getVersion() + " change-id " + metadata.getChangeId());
         out.println("Copyright (C) 2008-2014 Shevek (http://www.anarres.org/).");
         out.println("This is free software; see the source for copying conditions.  There is NO");
         out.println("warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.");