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  1. JDK
  2. JDK-4730642

'!' within a directory name is misidentified as the jar separator

    Details

    • Subcomponent:
    • CPU:
      generic, x86
    • OS:
      generic, windows_xp

      Description

      The methods java.lang.Class.getResourceAsStream and java.lang.ClassLoader.getResourceAsStream returns null if an exclamation mark is part of the working dir.
      In other words:
      Reading from a jar which is stored in a directory which contains an exclamation mark will throw a NullPointerException.

      If you read a text file from a jar usually you use the instruction
      Inputstream is = getClass().getResourceAsStream("a_file_in_jar");

      Usually the method getResourceAsStream returns an Object of class InputStream if the file exists in the jar. But, if you store the jar file in a directory which directoryname contains an exclamation mark, e. g. "!oops" or "bug!" or "Go!Zilla" the method getResourceAsStream will return null instead of an InputStream object. This will cause a NullPointerException if you want to read from the file.

      I've found this bug in 1.3.1_04, 1.4.0_01 and 1.4.1 beta in both Solaris and Windows JRE distributions.

      Testcase:
      ---------
      1. Make a directory where an exclamation mark is part of the directoryname
      and change into that directory
      (use ksh and "back slash, exclamation mark") to avoid shell-interpretation)
      % ksh
      $ mkdir Go\!Zilla
      $ cd Go\!Zilla

      2. Create source ReadFromJar.java

      $ cat ReadFromJar.java
      import java.io.*;

      public class ReadFromJar {

        public static void main(String[] args) {
          new ReadFromJar();
        }
       
        public ReadFromJar() {
           readTextFromJar("ReadFromJar.java");
        }
       
        public void readTextFromJar(String s) {
          String thisLine;
          try {
            InputStream is = getClass().getResourceAsStream(s);
            // returns null if a ! is part of the directory name
            BufferedReader br = new BufferedReader (new InputStreamReader(is));
            while ((thisLine = br.readLine()) != null) {
               System.out.println(thisLine);
            }
          } catch (Exception e) {
            e.printStackTrace();
          }
        }
      }

      3. Compile ReadFromJar.java
      $ java -version
      java version "1.4.1-beta"
      Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.1-beta-b14)
      Java HotSpot(TM) Client VM (build 1.4.1-beta-b14, mixed mode)

      $ javac ReadFromJar.java

      4. Create a jar file and include source and class
      $ jar cfv ReadFromJar.jar ReadFromJar*

      5. Run the jar file, it should output the source code, but it throws an NullPointerException

      $ java -classpath ReadFromJar.jar ReadFromJar
      java.lang.NullPointerException
              at java.io.Reader.<init>(Reader.java:61)
              at java.io.InputStreamReader.<init>(InputStreamReader.java:55)
              at ReadFromJar.readTextFromJar(ReadFromJar.java:18)
              at ReadFromJar.<init>(ReadFromJar.java:10)
              at ReadFromJar.main(ReadFromJar.java:6)

      6. To see that it is usually working, just move the jar to a different directory
      $ mv ReadFromJar.jar /tmp
      $ cd /tmp
      $ java -classpath ReadFromJar.jar ReadFromJar
      import java.io.*;

      public class ReadFromJar {

        public static void main(String[] args) {
          new ReadFromJar();
        }
       
        public ReadFromJar() {
           readTextFromJar("ReadFromJar.java");
        }
       
        public void readTextFromJar(String s) {
          String thisLine;
          try {
            InputStream is = getClass().getResourceAsStream(s);
            // returns null if a ! is part of the directory name
            BufferedReader br = new BufferedReader (new InputStreamReader(is));
            while ((thisLine = br.readLine()) != null) {
               System.out.println(thisLine);
            }
          } catch (Exception e) {
            e.printStackTrace();
          }
        }
      }


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              • Assignee:
                Unassigned
                Reporter:
                jloefflm Johann Löfflmann (Inactive)
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                  Updated:
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