我跟着this example，当我启动命令（教程的指令）时，我收到以下错误：
PS C:\repository\liferay-plugins-sdk-6.2.0\XMLPortletFactory\example-xmlportletfactory> ant
Buildfile: C:\repository\liferay-plugins-sdk-6.2.0\XMLPortletFactory\example-xmlportletfactory\build.xml
[echo] Generating for SDK version =6.2.0
generate-portlet:
[java] May 19, 2014 4:37:31 PM org.xmlportletfactory.utils.XMLUtils validateAgainstSchema
[java] SEVERE: null
[java] com.sun.org.apache.xerces.internal.impl.io.MalformedByteSequenceException: Invalid byte 1 of 1-byte UTF-8 sequence.
...
BUILD FAILED
C:\repository\liferay-plugins-sdk-6.2.0\XMLPortletFactory\example-xmlportletfactory\build.xml:19: Java returned: 1
Total time: 0 seconds
PS C:\repository\liferay-plugins-sdk-6.2.0\XMLPortletFactory\example-xmlportletfactory>
如何说ant使用utf-8编码？如果我更改xml中的编码，我会收到以下错误：
PS C:\repository\liferay-plugins-sdk-6.2.0\XMLPortletFactory\example-xmlportletfactory> ant
Buildfile: C:\repository\liferay-plugins-sdk-6.2.0\XMLPortletFactory\example-xmlportletfactory\build.xml
BUILD FAILED
Encoding of project file C:\repository\liferay-plugins-sdk-6.2.0\XMLPortletFactory\example-xmlportletfactory\build.xml is invalid.
Total time: 0 seconds
PS C:\repository\liferay-plugins-sdk-6.2.0\XMLPortletFactory\example-xmlportletfactory>