title: Why doe not Android let me load JAR file from sd card?
body: <p>I have copied a JAR file to the SD card and have modified the BOOTCLASSPATH to reflect the same in the class path.</p>
  
  <pre><code>adb shell export BOOTCLASSPATH=/sdcard/Download/android-async-http.jar:$BOOTCLASSPATH
  </code></pre>
  
  <p>After modifying the class path, I am trying to launch the APK that depends on the specified JAVA library,</p>
  
  <pre><code>am start -n com.package.example/com.package.example.MyActivity
  </code></pre>
  
  <p>Now, the activity runs but with out the JAVA Library and I get the following error,</p>
  
  <pre><code>Unable to process classpath element '/sdcard/Download/android-async-http.jar'
  </code></pre>
  
  <p>Can someone explain why does this happen?</p>