Retrotranslator |
Retrotranslator-n.n.n-bin.zip
,
where n.n.n is the latest Retrotranslator release number.
myclasses
.
Retrotranslator-n.n.n-bin
and execute:java -jar retrotranslator-transformer-n.n.n.jar -srcdir myclasses
retrotranslator-runtime-n.n.n.jar
and
backport-util-concurrent.jar
into the classpath of your application.
The full command line syntax:
java -jar retrotranslator-transformer-n.n.n.jar <options>
or
java -cp retrotranslator-transformer-n.n.n.jar net.sf.retrotranslator.transformer.Retrotranslator <options>
Option | Description | Default |
---|---|---|
-srcdir |
Directory with classes compiled using JDK 5.0 (may be specified several times). | - |
-srcjar |
JAR file with classes compiled using JDK 5.0 (may be specified several times). | - |
-destdir |
Directory to place classes compatible with J2SE 1.4. | Location of sources |
-destjar |
JAR file to place classes compatible with J2SE 1.4. | Location of sources |
-stripsign |
Asks the translator to strip signature (generics) information. | Off |
-verbose |
Asks the translator for verbose output. | Off |
-lazy |
Asks the translator to transform only Java 5 classes. | Off |
-advanced |
Allows to override Java 1.4 methods for better Java 5 compatibility. | Off |
-verify |
Asks the translator for warnings when references to unknown classes, methods, or fields are found. | Off |
-classpath |
The classpath to use for verification including rt.jar , jce.jar ,
jsse.jar (from JRE 1.4), retrotranslator-runtime-n.n.n.jar ,
and backport-util-concurrent.jar . |
Current classpath |
-srcmask |
Files to translate (either bytecode or UTF-8 text) , e.g. "*.class;*.tld ".
Only three special characters are supported: "*?; ". |
*.class |
-embed |
Package name for a private copy of retrotranslator-runtime-n.n.n.jar and
backport-util-concurrent.jar to be put into -destdir or -destjar .
This makes your application independent of other versions of Retrotranslator present in the classpath.
|
- |
-retainapi |
Asks the translator to modify classes for JVM 1.4 compatibility but keep use of Java 5 API.
References introduced by a compiler will also remain unchanged,
like the use of java.lang.StringBuilder for string concatenation
or the implicit valueOf method call for autoboxing. |
Off |
-retainflags |
Asks the translator to keep Java 5 specific access modifiers. | Off |
-backport |
Informs the translator about user-defined backport packages. Package names should be separated by semicolons. | - |
For example, if you have a Java 5 application myapplication5.jar
you can use the following command
to produce myapplication4.jar
that will run on J2SE 1.4 and is independent of Retrotranslator,
since required classes are added to the translated application with a different package name:
java -jar retrotranslator-transformer-n.n.n.jar
-srcjar myapplication5.jar -destjar myapplication4.jar -embed com.mycompany.internal
The distribution contains an integrated Apache Ant task
net.sf.retrotranslator.transformer.RetrotranslatorTask
. It has the following syntax:
Attribute | Description | Default |
---|---|---|
srcdir |
Directory with classes compiled using JDK 5.0. | - |
srcjar |
JAR file with classes compiled using JDK 5.0. | - |
destdir |
Directory to place classes compatible with J2SE 1.4. | Location of sources |
destjar |
JAR file to place classes compatible with J2SE 1.4. | Location of sources |
stripsign |
Asks the translator to strip signature (generics) information. | Off |
verbose |
Asks the translator for verbose output. | Off |
lazy |
Asks the translator to transform only Java 5 classes. | Off |
advanced |
Allows to override Java 1.4 methods for better Java 5 compatibility. | Off |
verify |
Asks the translator for warnings when references to unknown classes, methods, or fields are found. | Off |
classpath |
The classpath to use for verification including rt.jar , jce.jar ,
jsse.jar (from JRE 1.4), retrotranslator-runtime-n.n.n.jar ,
and backport-util-concurrent.jar .
|
Current classpath |
srcmask |
Files to translate (either bytecode or UTF-8 text) , e.g. "*.class;*.tld ".
Only three special characters are supported: "*?; ". |
*.class |
embed |
Package name for a private copy of retrotranslator-runtime-n.n.n.jar and
backport-util-concurrent.jar to be put into -destdir or -destjar .
This makes your application independent of other versions of Retrotranslator present in the classpath.
|
- |
retainapi |
Asks the translator to modify classes for JVM 1.4 compatibility but keep use of Java 5 API.
References introduced by a compiler will also remain unchanged,
like the use of java.lang.StringBuilder for string concatenation
or the implicit valueOf method call for autoboxing. |
Off |
retainflags |
Asks the translator to keep Java 5 specific access modifiers. | Off |
backport |
Informs the translator about user-defined backport packages. Package names should be separated by semicolons. | - |
failonwarning |
Indicates whether the build will fail when there are verification warnings. | On |
You may use nested src
elements to specify source directories or JAR files, and nested
classpath
elements to specify classpath for verification. For example:
<path id="classpath"> <fileset dir="lib" includes="**/*.jar"/> </path> <taskdef name="retrotranslator" classpathref="classpath" classname="net.sf.retrotranslator.transformer.RetrotranslatorTask" /> <retrotranslator destdir="build/classes14" verify="true"> <src path="build/classes15"/> <classpath location="${java14_home}/jre/lib/rt.jar"/> <classpath refid="classpath"/> </retrotranslator>
For Maven there is a Retrotranslator plugin from the Mojo Project.
To automatically translate and verify classes compiled by IntelliJ IDEA you may download a plugin that generates classes compatible with 1.4 virtual machines from your Java 5 source code.
JIT Retrotranslator is able to translate at runtime Java classes loaded with any classloader.
It works on J2SE 1.4 from Sun, IBM, BEA, and Apple, but does nothing on J2SE 5.0 and other platforms.
However translation at runtime consumes additional memory and processing resources and it will not
work if your classes make use of Java 5 API but were compiled with "-target 1.4
".
java -cp retrotranslator-transformer-n.n.n.jar
net.sf.retrotranslator.transformer.JITRetrotranslator <options> -jar <jarfile> [<args...>]
java -cp retrotranslator-transformer-n.n.n.jar:<classpath>
net.sf.retrotranslator.transformer.JITRetrotranslator <options> <class> [<args...>]
JITRetrotranslator.run()
from some JVM 1.4 compatible class
before Java 5 classes are loaded.
JIT Retrotranslator can accept -advanced
and -backport
options.
Package | Class | Methods and fields | Compatibility notes |
---|---|---|---|
java.lang.annotation | * (all classes) | * (all methods) | |
java.util.concurrent, |
almost all classes | almost all methods |
Supported via the
Backport of JSR 166. The Condition.awaitNanos(long) method is supported with
very little accuracy guarantees.
|
java.io | Closeable | * |
new Closeable[...] is replaced with new Object[...]
|
Flushable | * |
new Flushable[...] is replaced with new Object[...]
| |
PrintStream | * (11 new methods and constructors) | ||
PrintWriter | * (11 new methods and constructors) |
The PrintWriter.format and PrintWriter.printf methods always flush the output buffer.
| |
Reader | read(CharBuffer) | ||
Writer |
append(CharSequence),
| ||
java.lang | Appendable | * |
new Appendable[...] is replaced with new Object[...]
|
Boolean | parseBoolean(String), | ||
Byte | valueOf(byte) | ||
Character | valueOf(char) | ||
Class | * (21 new methods) |
Class.getMethod(String, Class...) and Class.getDeclaredMethod(String, Class...) are
intercepted in advanced mode to better support generics and covariant return types on several JVM implementations.
| |
Deprecated | * | ||
Double | valueOf(double) | ||
Enum | * | ||
Float | valueOf(float) | ||
IllegalArgumentException | IllegalArgumentException(String, Throwable), | ||
IllegalStateException | IllegalStateException(String, Throwable), | ||
Integer | valueOf(int), signum(int) | ||
Iterable | * |
new Iterable[...] is replaced with new Object[...]
| |
Long | valueOf(long), signum(long) | ||
Package | * (4 new methods) | ||
Readable | * |
new Readable[...] is replaced with new Object[...]
| |
Short | valueOf(short) | ||
String | contains(CharSequence), | ||
StringBuffer |
StringBuffer(CharSequence), | ||
StringBuilder |
All methods supported in StringBuffer
| StringBuilder is replaced with StringBuffer | |
SuppressWarnings | * | ||
System | nanoTime(), |
The System.nanoTime() method is supported via the
Backport of JSR 166
and its precision
may vary on different platforms.
| |
Thread | getStackTrace(), | The Thread.getStackTrace()
method returns non-empty stack trace only for the current thread.The Thread.getId() method does not reflect the order in which threads are created. | |
TypeNotPresentException | * | ||
java.lang.reflect |
AccessibleObject | * | |
AnnotatedElement | * |
new AnnotatedElement[...] is replaced with new Object[...]
| |
Constructor | * (11 new methods) | ||
Field | * (8 new methods) | ||
GenericArrayType | * | ||
GenericDeclaration | * |
new GenericDeclaration[...] is replaced with new Object[...]
| |
GenericSignatureFormatError | * | ||
MalformedParameterizedTypeException | * | ||
Method | * (14 new methods) | ||
ParameterizedType | * | ||
Type | * |
new Type[...] is replaced with new Object[...]
| |
TypeVariable | * | ||
WildcardType | * | ||
java.math | BigDecimal |
BigDecimal(int), | The BigDecimal.setScale(int, int)
method supports negative scales in advanced mode. |
java.rmi.server | RemoteObjectInvocationHandler |
* | |
java.net | URL |
toURI() | |
java.util.nio | CharBuffer |
append(CharSequence),
| |
java.util | AbstractQueue | * | Supported via the Backport of JSR 166. |
Arrays | * (21 new methods) | ||
Collections | * (13 new methods) | Supported via the Backport of JSR 166. | |
EnumMap | * | ||
EnumSet | * | ||
Formatter | * | ||
LinkedList | * (5 new methods) | ||
PriorityQueue | * | Supported via the Backport of JSR 166. | |
Queue | * |
Supported via the
Backport of JSR 166.new Queue[...] is replaced with new Object[...]
| |
UUID | * | ||
java.util.regex | Matcher |
quoteReplacement(String), | |
MatchResult | * |
new MatchResult[...] is replaced with new Object[...]
| |
Pattern | quote(String) |
Since most backported classes are discovered by Retrotranslator at translation time,
you may write an extension and simply put it into the Retrotranslator classpath to make it work.
For example, all references to
java.util.EnumSet
are replaced with references to
net.sf.retrotranslator.runtime.java.util.EnumSet_
(trailing underscore) if the latter can be found.
But if you replace a whole class that exists in J2SE 1.4 you may encounter interoperability issues with other libraries.
So, for example, support for Java 5 fields, methods, and constructors of
java.math.BigDecimal
is placed into
net.sf.retrotranslator.runtime.java.math._BigDecimal
(leading underscore):
convertConstructorArguments
method that
accepts constructor's arguments an returns an argument for a Java 1.4 constuctor.
Another approach for constructor backporting is used by
net.sf.retrotranslator.runtime.java.io._PrintStream
. There is a public static
createInstanceBuilder
method that accepts constructor's arguments an returns an object with public
argument1
...argumentN
methods and optional public void initialize
method.
All argumentX
methods provide arguments for a Java 1.4 constuctor and should not have any parameters.
The initialize
method has a single parameter for the created instance and may be used for postprocessing.
However, if the backported methods require access
to non-public methods or fields of the instance, they cannot be fully handled by Retrotranslator.
While you can use reflection to access any data, translated code generally should not depend on security settings.
For example, it is impossible to write an implementation for methods getSource()
and setSource()
of java.beans.PropertyEditorSupport
that will work in any environment.
Also this approach cannot be used to replace instance field references.
You can put your extensions into packages other than net.sf.retrotranslator.runtime
.
For example, to make Retrotranslator use com.mycompany.internal.java.lang._String
just specify -backport com.mycompany.internal
at the command line.
If you have written an extension that does not contain copyrighted code, you may send
a patch
under the Retrotranslator license.
Basically, only classes, methods, and fields listed above should work, and other features, like formatted input, are not supported. Known issues:
java -Djava.version=1.5.0 -Djava.specification.version=1.5 -Djava.class.version=49.0 ...
((Writer) new FileWriter("file.tmp")).append("Hello").close();
Retrotranslator: a Java bytecode transformer that translates Java classes compiled with JDK 5.0 into classes that can be run on JVM 1.4. Copyright (c) 2005, 2006 Taras Puchko All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 3. Neither the name of the copyright holders nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.