ant编译报错，怎么说包不存在啊
 [javac] D:\Users\lipeng.BJ\Workspaces\MyEclipse 10\openfire_src\src\plugins\sample\bulid\bulid.xml:29: warning: 'includeantruntime' was not set, defaulting to build.sysclasspath=last; set to false for repeatable builds
    [javac] Compiling 2 source files to D:\Users\lipeng.BJ\Workspaces\MyEclipse 10\openfire_src\src\plugins\sample\bin
    [javac] D:\Users\lipeng.BJ\Workspaces\MyEclipse 10\openfire_src\src\plugins\sample\src\ExamplePlugin.java:11: 软件包 org.jivesoftware.spark 不存在
    [javac] import org.jivesoftware.spark.SparkManager;
    [javac]                              ^
    [javac] D:\Users\lipeng.BJ\Workspaces\MyEclipse 10\openfire_src\src\plugins\sample\src\ExamplePlugin.java:12: 软件包 org.jivesoftware.spark 不存在
    [javac] import org.jivesoftware.spark.Workspace;
    [javac]                              ^
    [javac] D:\Users\lipeng.BJ\Workspaces\MyEclipse 10\openfire_src\src\plugins\sample\src\ExamplePlugin.java:13: 软件包 org.jivesoftware.spark.component.tabbedPane 不存在
    [javac] import org.jivesoftware.spark.component.tabbedPane.SparkTabbedPane;
    [javac]                                                   ^
    [javac] D:\Users\lipeng.BJ\Workspaces\MyEclipse 10\openfire_src\src\plugins\sample\src\ExamplePlugin.java:14: 软件包 org.jivesoftware.spark.plugin 不存在
    [javac] import org.jivesoftware.spark.plugin.Plugin;
    [javac]                                     ^
    [javac] D:\Users\lipeng.BJ\Workspaces\MyEclipse 10\openfire_src\src\plugins\sample\src\ExamplePlugin.java:17: 找不到符号
    [javac] 符号： 类 Plugin
    [javac] public class ExamplePlugin implements Plugin{
    [javac]                                       ^
    [javac] D:\Users\lipeng.BJ\Workspaces\MyEclipse 10\openfire_src\src\plugins\sample\src\ExamplePreference.java:8: 软件包 org.jivesoftware.spark.preference 不存在
    [javac] import org.jivesoftware.spark.preference.Preference;
    [javac]                                         ^
    [javac]