由于以下错误，ant 文件构建失败

Question

当我尝试运行 ant 文件时，构建将失败，原因如下：

[projectBuild] null DN Jaxb Beans:Multiple output locations are disabled, cannot associate entry: 'DN Jaxb Beans/src' with a specific output.
[projectBuild] null DN Jaxb Beans:Unbound classpath container: 'JRE System Library [J2SE-1.5]'.
[projectBuild] null DN Jaxb Beans:Unbound classpath container: 'org.maven.ide.eclipse.MAVEN2_CLASSPATH_CONTAINER'.
[projectBuild] null DN Jaxb Beans:Multiple output locations are disabled, cannot associate entry: 'DN Jaxb Beans/src' with a specific output.
[projectBuild] null DN Jaxb Beans:The project was not built since its classpath is incomplete. Cannot find the class file for java.lang.Object. Fix the classpath then try rebuilding this project.
[projectBuild] 1 JAXBVersion.java:This compilation unit indirectly references the missing type java.lang.Object (typically some required class file is referencing a type outside the classpath)
[projectBuild] Errors were detected after building DN Jaxb Beans
[projectBuild] ProjectBuild: DN Jaxb Beans Exception=Errors were detected after building DN Jaxb Beans
[projectBuild] BUILD FAILED: file:C:/workspace.May21/DN Ant Scripts/buildDev.xml:149: 

ProjectBuild: DN Jaxb Beans Exception=Errors were detected after building DN Jaxb Beans
Total time: 19 minutes 4 seconds

你能解决这个问题吗？

Answer 1

以下错误是一个很好的指示：

Cannot find the class file for java.lang.Object

如果 java 找不到 java.lang.Object，那么您的 java 安装存在配置问题。消息JRE System Library [J2SE-1.5] 看起来像一个eclipse jre 配置名称，所以我假设您正在通过eclipse 运行它。我会尝试在 eclipse 的执行环境配置中删除并重新添加。