(MyClass)Class.forName(variable).newInstance()".
Depending on your application, you may need to keep the mentioned classes
with an option like "-keep class MyClass", or their
implementations with an option like "-keep class * implements
MyClass". You can switch off these notes by specifying the
-dontnote option..getField("myField")". Depending on your application, you
may need to figure out where the mentioned class members are defined and
keep them with an option like "-keep class MyClass { MyFieldType
myField; }". Otherwise, ProGuard might remove or obfuscate the
class members, since it can't know which ones they are exactly. It does
list possible candidates, for your information. You can switch off these
notes by specifying the -dontnote option.-keep option to preserve the
given method (or field), but no -keep option for the given
class that is an argument type or return type in the method's descriptor.
You may then want to keep the class too. Otherwise, ProGuard will
obfuscate its name, thus changing the method's signature. The method might
then become unfindable as an entry point, e.g. if it is part of a public
API. You can switch off these notes by specifying the -dontnote option.-dontnote option.ProGuard may terminate when it encounters parsing errors or I/O errors, or some more serious warnings:
-libraryjars option.
If the class that is reported as missing is a non-public library class,
you should specify the -dontskipnonpubliclibraryclasses
option. A common example is the class
java.util.zip.ZipConstants, which is used as an interface
class in some public classes, even though it is only package visible (in
this case, the warning could also be ignored, because the class is not a
fundamental part of the class hierarchy).
If you're missing a library and you're absolutely sure it isn't used
anyway, you can try your luck with the -ignorewarnings option,
or even the -dontwarn
option.
If the class member that is reported as missing is actually implemented in
a non-public library class, you should specify the
-dontskipnonpubliclibraryclasses option. A common example is
the method setLength(int) in the public class
java.lang.StringBuilder. This method is actually defined in
the package visible superclass
java.lang.AbstractStringBuilder, which ProGuard ignores by
default.
If your program classes reside in the same packages as library classes,
and refer to their package visible class members, then you should specify
the -dontskipnonpubliclibraryclassmembers
option.
WEB-INF/classes directory in a war should be packaged
in a jar and put in the WEB-INF/lib directory. If you don't
mind these classes not being written to the output, you can specify the -ignorewarnings option,
or even the -dontwarn
option.-keep option in the
configuration, and the mapping file, in the obfuscation step. The given
class name or class member name can't be kept by its original name, as
specified in the configuration, but it has to be mapped to the other given
name, as specified in the mapping file. You should adapt your
configuration or your mapping file to remove the conflict. Alternatively,
if you're sure the renaming won't hurt, you can specify the -ignorewarnings option,
or even the -dontwarn
option.-ignorewarnings option,
or even the -dontwarn
option. Note that you should always use the -useuniqueclassmembernames
option in the initial obfuscation step, in order to reduce the risk of
conflicts.-keep options, or you mistyped the
class names. ProGuard has to know exactly what you want to keep: an
application, an applet, a servlet, a midlet,..., or any combination of
these. Without the proper seed specifications, ProGuard would shrink,
optimize, or obfuscate all class files away.<java.home>/lib/rt.jar by
<java.home>/../Classes/classes.jar.Should ProGuard crash while processing your application:
-Xms and -Xmx options). You can also
reduce the amount of memory that ProGuard needs by removing unnecessary
library jars from your configuration, or by filtering out unused library
packages and classes. Remember that only classes or interfaces that are
extended or implemented by classes in your input jars are required.-Xss option)
should help too. In practice however, the -Xss setting
doesn't have any effect on the main thread, due to Sun Bug
#4362291. As a result, this solution will only work when running
ProGuard in a different thread, e.g. from its GUI.-dontoptimize option. In
any case, please report the problem, preferably with the simplest example
that causes ProGuard to crash.-dontusemixedcaseclassnames
option.
Also, you should make sure your class files are in directories that
correspond to their package names. ProGuard will read misplaced class
files, but it will currently not write their processed versions. Notably,
class files that are in the WEB-INF/classes directory in a
war should be packaged in a jar and put in the WEB-INF/lib
directory.
-printseeds option to see
which elements are being kept exactly.
If you are using marker interfaces to keep other classes, the marker interfaces themselves are probably being removed in the shrinking step. You should therefore always explicitly keep any marker interfaces.
LocalVariableTable or LocalVariableTypeTable
attributes.preverify tool always unpacks the jars, so class files with
similar lower-case and upper-case names overwrite each other. You can use
ProGuard's -dontusemixedcaseclassnames
option to work around this problem.
If the above doesn't help, there is probably a bug in the optimization
step of ProGuard. Make sure you are using the latest version. You should
be able to work around the problem by using the -dontoptimize option. You
can check the bug database to see if it is a known problem (often with a
fix). Otherwise, please report it, preferably with the simplest example on
which you can find ProGuard to fail.
-microedition option,
ProGuard will preverify the class files for Java Micro Edition.
Class.forName, trying to create
the missing class dynamically. ProGuard can only detect constant name
arguments, like Class.forName("mypackage.MyClass"). For
variable name arguments like Class.forName(someClass), you
have to keep all possible classes using the appropriate -keep option, e.g. "-keep
class mypackage.MyClass" or "-keep class * implements
mypackage.MyInterface".myClass.getMethod, trying to find some method dynamically.
Since ProGuard isn't detecting this (yet), you have to keep the missing
method in using the appropriate -keep option, e.g. "-keep
class mypackage.MyClass { void myMethod(); }".-adaptresourcefilenames
and/or -adaptresourcefilecontents.
Note that directory entries in jar files aren't copied at all. If you refer to any directories from your code, you should add them manually.
-jar instead of the option -classpath. The java
virtual machine returns with this error message if your jar doesn't
contain a manifest file (META-INF/MANIFEST.MF), if the
manifest file doesn't specify a main class (Main-Class: ...),
or if the jar doesn't contain this main class. You should then make sure
that the input jar contains a valid manifest file to start with, that this
manifest file is the one that is copied (the first manifest file that is
encountered), and that the main class is kept in your configuration,-microedition option, so
the processed class files are preverified properly.-repackageclasses
'' and -overloadaggressively.
If you're using the JME WTK plugin, you can adapt the configuration
proguard/wtk/default.pro that's inside the
proguard.jar.-useuniqueclassmembernames
option. It avoids overloading class member names, which triggers a bug in
their java virtual machine.
You might also try using the -dontusemixedcaseclassnames
option. Even if the midlet has been properly processed and then
preverified on a case-sensitive file system, the device itself might not
like the mixed-case class names. Notably, the Nokia N-Gage emulator works
fine, but the actual device seems to exhibit this problem.
volatile. If this is not
possible for some reason, you'll have to switch off optimization using the
-dontoptimize
option.-overloadaggressively
option. This option triggers a bug in
sun.tools.java.MethodSet.add in Sun's JDK 1.2.2, which is
used for (dynamic) compilation. You should then avoid this option.-overloadaggressively
option. You should then use the same option again in the second processing
round.Furthermore, you should check whether you have specified your program jars and library jars properly. Program classes can refer to library classes, but not the other way around.
If all of this seems ok, perhaps there's a bug in ProGuard (gasp!). If so, please report it, preferably with the simplest example on which you can find ProGuard to fail.
-dontoptimize
option. You can check the bug database to see if it is a known problem
(often with a fix). Otherwise, please report it, preferably with the
simplest example on which ProGuard fails.