我有一个构造函数在第一次调用new
时失败,因为类javax.persistence.NoResultException
的异常被捕获到一个类的方法中。类构造函数无法抛出类加载异常
编辑:它不是NoResultException,NoResultException是异常的消息。 stackTrace低于
如果我删除导入到javax.persistence.NoResultException
并只捕获一般Exception e
,代码工作。
我的问题是:
- 为什么一个方法里面的代码还没有被称为是影响构造? (也没有在构造函数中调用)
- 为什么ClassLoader抛出一个不应该抛出的异常?根据JavaDoc,ClassLoader.loadClass()抛出
ClassNotFoundException
。
,对于javax.persistence.NoResultException赶上以及进口老代码管理版本之间生存,我删除它和它的固定的,但是我想现在这背后的原因。
堆栈跟踪:
java.lang.NoClassDefFoundError: javax/persistence/NoResultException
at xxx.xxxxxx.xxxxxxx.xxxx.xxxx.xxxxxxxxxxxx.xxxxxxxxxxxxxxx(ClassB.java)
...
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Caused by: java.lang.ClassNotFoundException: javax.persistence.NoResultException
at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:307)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:301)
at java.lang.ClassLoader.loadClass(ClassLoader.java:252)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:320)
... 10 more
走到尽头,看一步一个调试器中的步骤的图像和失败
失败CODE的时刻:
// ClassB.java
import javax.persistence.NoResultException; // NOTICE THE IMPORT
public ClassB{
private UserInfo user;
private WebServiceBDelegate port;
private Connection conn;
public ClassB (UserInfo user, Connection conn) throws Exception {
System.out.println("CLASS B CONSTRUCTOR");
this.user = user;
this.conn = conn;
this.port = new WebServiceBService().getForwardingPort();
}
public boolean methodB(List<String> list){
try{
// Check some stuff on database using this.conn
} catch(NoResultException nre){ // NOTICE THE CATCH
String something = getSomething();
}
// Get the values to invoke SOAP service using this.conn
status = port.operationB(values);
if(status > 0)
return true;
return false;
}
}
WORKING CODE:
// ClassB.java
public ClassB{
private UserInfo user;
private WebServiceBDelegate port;
private Connection conn;
public ClassB (UserInfo user, Connection conn) throws Exception {
System.out.println("CLASS B CONSTRUCTOR");
this.user = user;
this.conn = conn;
this.port = new WebServiceBService().getForwardingPort();
}
public boolean methodB(List<String> list){
try{
// Check some stuff on database using this.conn
} catch(Exception e){ // THIS IS THE CHANGED CATCH
String something = getSomething();
}
// Get the values to invoke SOAP service using this.conn
status = port.operationB(values);
if(status > 0)
return true;
return false;
}
}
下面是调试器一步一步图片进入类的构造函数时,在JVM默认的ClassLoader的那一刻失败:
STEP INTO when calling new ClassB gets me to loadClassInternal(String)
STEP INTO loadClassInternal(String), gets me to loadClass(String,boolean)
STEP INTO loadClass(String,boolean), as far as I can get, now STEP RETURN
STEP RETURN gets me to loadClass(String)
STEP OVER gets me to loadClassInternal(String)
STEP OVER gives me javax.persistence.NoResultException
STEP OVER把我带回到甲终于在我的代码,并结束EXECUTION
可能重复http://stackoverflow.com/questions/2613113/javax-persistence-noresultexception-getsingleresult-did-not-retrieve-any-enti – amicngh 2012-07-31 10:59:38
这不是重复的,一个人的交易,不同之处是抛出,这似乎是关于类加载/类路径问题。 – 2012-07-31 11:01:05