eclipse打jar包后出错：class file(s) on classpath not found or not accessible

到新公司导入的新项目；

环境eclipse是3.4，jdk是1.5，tomcat是5.5的，现在看来是有点老了。

导出jar包时报错如下：

JAR creation failed. See details for additional information.
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/BankTransInfo.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/VirementResponseHandler.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/DBAcctBalanceInfo.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/InstructionPostResult.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/ExtAccountInfo.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/BankInstructionInfo.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/DBAcctTransInfo.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/BankBalanceInfo.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/autotask/AutoHisDataDisplaceTask.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/autotask/ImportHisDatesTask.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/autotask/AutoCancelTask.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/autotask/AutoRecContTask.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/autotask/AutoSendTask.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/autotask/TaskManager.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/autotask/CheckBankHisDataTask.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/autotask/AutoImportCheckAT800Task.java
class file(s) on classpath not found or not accessible iTMS_BANKINTERFACF/src/com/iss/bankinterface/autotask/ImportHisDatesofMonthTask.java

网上有一些方法，我的是发现放classes文件夹中并没有编译的内容。classes文件夹位置如下：

 正常的话部署好tomcat和jdk后，classes中都会有编译的文件，而且是自动编译的。

我发现我这里面没有东西，我又设置了一下eclipse的自动编译：如下勾选build  ----，然后clean，然后重启eclipse。但是还没有classes文件。

最后，我由删除了项目，重新导入了一次，classes里面有内容了。

不报错了，但是解决方法没有弄明白，各位提示一下。