Zxing compiled 2.0 with Java 1.5

Question

Hi I have to used the javase zxing module. I have read the zxing getting start and I have tried to compile core and javase modules (with JDK 1.5.0_22)

I run ant script in core folder, I have this error:

[javac] javac: invalid target release: 6

If I modify the ant script build.xml in core folder replacing target=6 with target=5 and source=6 with source=5 I have 42 errors of compilation:

init:

build:
    [javac] Compiling 169 source files to D:\ZXing-2.0\zxing-2.0\core\build
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\MultiFormatReader.j
ava:52: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\MultiFormatReader.j
ava:66: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\MultiFormatReader.j
ava:157: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\MultiFormatWriter.j
ava:40: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\MultiFormatWriter.j
ava:48: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\aztec\AztecReader.j
ava:52: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\aztec\AztecReader.j
ava:57: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\aztec\AztecReader.j
ava:89: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\datamatrix\DataMatr
ixReader.java:57: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\datamatrix\DataMatr
ixReader.java:62: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\datamatrix\DataMatr
ixReader.java:89: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\datamatrix\detector
\Detector.java:444: method does not override a method from its superclass
    [javac]     @Override
    [javac]      ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\maxicode\MaxiCodeRe
ader.java:58: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\maxicode\MaxiCodeRe
ader.java:63: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\maxicode\MaxiCodeRe
ader.java:84: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\multi\ByQuadrantRea
der.java:46: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\multi\ByQuadrantRea
der.java:52: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\multi\ByQuadrantRea
der.java:95: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\multi\GenericMultip
leBarcodeReader.java:55: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\multi\GenericMultip
leBarcodeReader.java:60: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\qrcode\QRCodeReader
.java:61: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\qrcode\QRCodeReader
.java:66: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\qrcode\QRCodeReader
.java:93: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\multi\qrcode\QRCode
MultiReader.java:47: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\multi\qrcode\QRCode
MultiReader.java:52: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\qrcode\detector\Fin
derPatternFinder.java:557: method does not override a method from its superclass

    [javac]     @Override
    [javac]      ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\qrcode\detector\Fin
derPatternFinder.java:573: method does not override a method from its superclass

    [javac]     @Override
    [javac]      ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\multi\qrcode\detect
or\MultiFinderPatternFinder.java:80: method does not override a method from its
superclass
    [javac]     @Override
    [javac]      ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\oned\OneDReader.jav
a:47: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\oned\OneDReader.jav
a:53: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\oned\OneDReader.jav
a:87: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\oned\OneDimensional
CodeWriter.java:40: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\oned\OneDimensional
CodeWriter.java:53: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\oned\UPCAWriter.jav
a:36: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\oned\UPCAWriter.jav
a:42: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\pdf417\PDF417Reader
.java:53: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\pdf417\PDF417Reader
.java:58: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\pdf417\PDF417Reader
.java:76: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\pdf417\encoder\PDF4
17Writer.java:32: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\pdf417\encoder\PDF4
17Writer.java:41: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\qrcode\QRCodeWriter
.java:40: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] D:\ZXing-2.0\zxing-2.0\core\src\com\google\zxing\qrcode\QRCodeWriter
.java:47: method does not override a method from its superclass
    [javac]   @Override
    [javac]    ^
    [javac] Note: Some input files use unchecked or unsafe operations.
    [javac] Note: Recompile with -Xlint:unchecked for details.
    [javac] 42 errors

BUILD FAILED
D:\ZXing-2.0\zxing-2.0\core\build.xml:37: Compile failed; see the compiler error
 output for details.

Thanks

Pretty simple: as you can see, the library requires Java 6. You can't just change that to Java 5 and expect it to work. — Sean Owen, Mar 14 '12 at 10:38
I don't know the I have to remove the source attribute in javac tag. — Michel Foucault, Mar 15 '12 at 10:46

Thorbjørn Ravn Andersen · Answer 1 · 2012-03-14T08:36:00.453

3

This is Java 6 syntax which cannot be parsed by Java 5 javac.

Install and use a Java 6 JDK which has a Java 6 javac.

(If you cannot do that, you can experiment with using the Eclipse compiler which can compile Java 6 sources using a Java 5 JVM - http://help.eclipse.org/indigo/topic/org.eclipse.jdt.doc.user/tasks/task-ant_javac_adapter.htm - you will also need to download an appropriate version of ecj.jar)

edited Mar 14 '12 at 08:36

answered Mar 14 '12 at 08:16

Thorbjørn Ravn Andersen

73,784
33
194
347

`@Override` was introduced since JDK 5. So it can be compiled with JDK 1.5 – Buhake Sindi Mar 14 '12 at 08:21
It is true, but with JDK 5 don't compile – Michel Foucault Mar 14 '12 at 08:28
1

@TheEliteGentleman the semantics of @-Override has changed between Java 5 and Java 6. Check out the usage in interfaces. – Thorbjørn Ravn Andersen Mar 14 '12 at 08:33
the source can be 1.7 and compiled to a 1.5 target. remember to use `bootclasspath`. annotations don't exist in the generated class files :) – Janus Troelsen Mar 26 '14 at 13:45

score 2 · Accepted Answer · edited May 23 '17 at 12:04

2

You have to use a javac version 6 with options -source 6 and -target 5! See also this question.

UPDATE: remove the -source option, that should work using a javac version 6

> javac -version
javac 1.6.0_22
> javac -target 5 ...

edited May 23 '17 at 12:04

Community

1
1

answered Mar 14 '12 at 08:14

Arne Burmeister

20,046
8
53
94

I have tried: this is the error: [javac] javac: source release 6 requires target release 1.6 – Michel Foucault Mar 14 '12 at 08:19

score 0 · Answer 3 · answered Mar 01 '13 at 18:22

It's working fine for zxing-2.1. I did the following changes:

build.xml:

<target name="build" depends="init">
  <mkdir dir="build"/>
  <javac srcdir="src"
     destdir="build"
     source="5"
     target="5"

pom.xml

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-compiler-plugin</artifactId>
  <version>2.4</version>
  <configuration>
    <source>5</source>
    <target>5</target>
  </configuration>
</plugin>

And was able to compile (mvn clean package) both core & javase with no issues.

Zxing compiled 2.0 with Java 1.5

3 Answers3