Question

我正在使用sun / oracle jdk 1.6.0_32并且javac编译器似乎为目标1.5 jvm而不是1.6创建类文件。它不会接受-source 1.6 -target 1.6。用javap查看生成的类文件显示了一个主要版本：49不是50，正如我所料。 Eclipse Indigo正确创建了1.6兼容的类文件，主要版本为：50。我在eclipse中使用ant 1.8.2时首先注意到这一点，并且无法将源或目标属性设置为1.6。有什么我做错了吗？

附录

我只安装了1个jdk（1.6.0_32）。从命令行我得到以下内容。

ken@kryten:~/projects/simpleHelloWorld/bin/com/kwcons$ ls -al
total 8
drwxr-xr-x 2 ken ken 4096 2012-06-28 16:50 .
drwxr-xr-x 3 ken ken 4096 2012-06-28 16:46 ..
ken@kryten:~/projects/simpleHelloWorld/bin/com/kwcons$ javac -d /home/ken/projects/simpleHelloWorld/bin -version /home/ken/projects/simpleHelloWorld/src/com/kwcons/HelloWorld.java
javac 1.6.0_32
ken@kryten:~/projects/simpleHelloWorld/bin/com/kwcons$ ls -al
total 12
drwxr-xr-x 2 ken ken 4096 2012-06-28 16:50 .
drwxr-xr-x 3 ken ken 4096 2012-06-28 16:46 ..
-rw-r--r-- 1 ken ken  441 2012-06-28 16:50 HelloWorld.class
ken@kryten:~/projects/simpleHelloWorld/bin/com/kwcons$ /usr/lib/jvm/java-6-sun/bin/javap -verbose HelloWorld |grep major
  major version: 49
ken@kryten:~/projects/simpleHelloWorld/bin/com/kwcons$

如果我使用-source和-target，这就是我得到的。

ken@kryten:~/projects/simpleHelloWorld/bin/com/kwcons$ javac -d /home/ken/projects/simpleHelloWorld/bin -version -source 1.6 -target 1.6 /home/ken/projects/simpleHelloWorld/src/com/kwcons/HelloWorld.java
javac 1.6.0_32
javac: invalid source release: 1.6
Usage: javac <options> <source files>
where possible options include:
  -g                         Generate all debugging info
  -g:none                    Generate no debugging info
  -g:{lines,vars,source}     Generate only some debugging info
  -nowarn                    Generate no warnings
  -verbose                   Output messages about what the compiler is doing
  -deprecation               Output source locations where deprecated APIs are used
  -classpath <path>          Specify where to find user class files
  -cp <path>                 Specify where to find user class files
  -sourcepath <path>         Specify where to find input source files
  -bootclasspath <path>      Override location of bootstrap class files
  -extdirs <dirs>            Override location of installed extensions
  -endorseddirs <dirs>       Override location of endorsed standards path
  -d <directory>             Specify where to place generated class files
  -encoding <encoding>       Specify character encoding used by source files
  -source <release>          Provide source compatibility with specified release
  -target <release>          Generate class files for specific VM version
  -version                   Version information
  -help                      Print a synopsis of standard options
  -X                         Print a synopsis of nonstandard options
  -J<flag>                   Pass <flag> directly to the runtime system

ken@kryten:~/projects/simpleHelloWorld/bin/com/kwcons$

我在eclipse中得到了与ant相同的输出。

Answer 1

试试这个 1）在ant脚本中指定jdk版本

2）在你的“编译”目标中写下以下javac目标，

runtime-libs ::它将指向您的项目lib目录。在属性中声明。

<javac
bootclasspath="${runtime-libs}/rt.jar"
target="1.6"
source="1.6"
includeJavaRuntime="false"
includeAntRuntime="false"
debug="yes"
destdir="${build-dir}">
<classpath refid="project.class.path"/>
<src path="${code}"/>
</javac>

Java类主要版本

1 个答案: