Package com.jcabi.manifests

Class Manifests

java.lang.Object
com.jcabi.manifests.Manifests
All Implemented Interfaces:
MfMap
public final class Manifests extends Object implements MfMap
Static reader of META-INF/MANIFEST.MF files. The class provides convenient methods to read all MANIFEST.MF files available in classpath and all attributes from them.

This mechanism may be very useful for transferring information from continuous integration environment to the production environment. For example, you want your site to show project version and the date of WAR file packaging. First, you configure maven-war-plugin to add this information to MANIFEST.MF: 

 <plugin>
  <artifactId>maven-war-plugin</artifactId>
  <configuration>
   <archive>
    <manifestEntries>
     <Foo-Version>${project.version}</Foo-Version>
     <Foo-Date>${maven.build.timestamp}</Foo-Date>
    </manifestEntries>
   </archive>
  </configuration>
 </plugin>

maven-war-plugin will add these attributes to your MANIFEST.MF file and the project will be deployed to the production environment. Then, you can read these attributes where it's necessary (in one of your JAXB annotated objects, for example) and show to users: 

  import com.jcabi.manifests.Manifest;
 import java.text.SimpleDateFormat;
 import java.util.Date;
 import java.util.Locale;
 import jakarta.xml.bind.annotation.XmlElement;
 import jakarta.xml.bind.annotation.XmlRootElement;
 @XmlRootElement
 public final class Page {
   @XmlElement
   public String version() {
     return Manifests.read("Foo-Version");
   }
   @XmlElement
   public Date date() {
     return new SimpleDateFormat("yyyy.MM.dd", Locale.ENGLISH).parse(
       Manifests.read("Foo-Date");
     );
   }
 }

If you want to add more manifests to the collection, use its static instance: 

Manifests.singleton().append(new FilesMfs(new File("MANIFEST.MF")));

You can also modify the map directly: 

Manifests.singleton().put("Hello", "world");

The only dependency you need (check the latest version at jcabi-manifests): 

 <dependency>
  <groupId>com.jcabi</groupId>
  <artifactId>jcabi-manifests</artifactId>
 </dependency>
Since:
0.7

  • Constructor Details

    • Manifests

      public Manifests()
      Public ctor.
      Since:
      1.0

    • Manifests

      public Manifests(Map<String,String> attrs)
      Public ctor.
      Parameters:
      attrs - Attributes to encapsulate
      Since:
      1.0

  • Method Details

    • singleton

      public static MfMap singleton()
      Get the singleton.
      Returns:
      The singleton
      Since:
      2.0.0

    • size

      public int size()
      Description copied from interface: MfMap
      Get size of attributes map.
      Specified by:
      size in interface MfMap
      Returns:
      Size of attributes map

    • isEmpty

      public boolean isEmpty()
      Description copied from interface: MfMap
      Check if attributes map is empty.
      Specified by:
      isEmpty in interface MfMap
      Returns:
      True if attributes map is empty and false otherwise

    • containsKey

      public boolean containsKey(String key)
      Description copied from interface: MfMap
      Check if attributes map contains the given key.
      Specified by:
      containsKey in interface MfMap
      Parameters:
      key - Attribute name
      Returns:
      True if attributes map contains the given key, and false otherwise

    • containsValue

      public boolean containsValue(String value)
      Description copied from interface: MfMap
      Check if attributes map contains the given value.
      Specified by:
      containsValue in interface MfMap
      Parameters:
      value - Attribute value
      Returns:
      True if attributes map contains the given value, and false otherwise

    • get

      public String get(String key)
      Description copied from interface: MfMap
      Get attribute value by its key.
      Specified by:
      get in interface MfMap
      Parameters:
      key - Attribute name
      Returns:
      Value of the attribute, and null if attribute not found

    • getAsMap

      public Map<String,String> getAsMap()
      Description copied from interface: MfMap
      Get a copy of attributes map.
      Specified by:
      getAsMap in interface MfMap
      Returns:
      Copy of attributes map

    • keySet

      public Set<String> keySet()
      Description copied from interface: MfMap
      Get a copy of a set of attributes keys.
      Specified by:
      keySet in interface MfMap
      Returns:
      Copy of a set of attributes keys

    • append

      public void append(Mfs mfs) throws IOException
      Description copied from interface: MfMap
      Append this collection of MANIFEST.MF files. This method changes the original instance.
      Specified by:
      append in interface MfMap
      Parameters:
      mfs - Content to append
      Throws:
      IOException - If fails on I/O problem

    • read

      public static String read(String name)
      Read one attribute available in one of MANIFEST.MF files.

      If such an attribute doesn't exist IllegalArgumentException will be thrown. If you're not sure whether the attribute is present or not use exists(String) beforehand.

      The method is thread-safe.

      Parameters:
      name - Name of the attribute
      Returns:
      The value of the attribute retrieved

    • exists

      public static boolean exists(String name)
      Check whether attribute exists in any of MANIFEST.MF files.

      Use this method before read(String) to check whether an attribute exists, in order to avoid a runtime exception.

      The method is thread-safe.

      Parameters:
      name - Name of the attribute to check
      Returns:
      Returns TRUE if it exists, FALSE otherwise