通过叉=FALSE的＆LT; java的＆GT; 任务将使用加载类的只有的从任务本身的类路径（即 classpathref 属性或＆LT;＆类路径GT; 嵌套元素），除了组特定的硬件codeD包$ P $的pfixes 它会尝试，如果他们没有对任务的自己的类路径发现从父加载器加载。由于了com.sun.xml 这不就是硬codeD名单上不会被委派到父，因此会给你一个 ClassNotFoundException的。

With fork="false" the <java> task uses a special "isolated" classloader that loads classes only from the task's own classpath (the classpathref attribute or <classpath> nested element), except for a specific set of hard-coded package prefixes which it will attempt to load from the parent loader if they are not found on the task's own classpath. Since com.sun.xml isn't on this hard-coded list it will not be delegated to the parent and so will give you a ClassNotFoundException.