Question

如果我尝试在DB中插入现有对象，我会得到一个抛出异常的方法。

 public void addInDB() throws Exception {
    if (isInBase()){
          throw new Exception ("[ReqFamily->addInDB] requirment already in base");
    }
    int idParent = m_parent.getIdBdd();

    idBdd = pSQLRequirement.add(name, description, 0, idParent,   
    ReqPlugin.getProjectRef().getIdBdd(), 100);
}

因此，当抛出异常时，我想抓住它并在我的托管bean中显示错误消息。

PS：在我的托管bean中，我只是调用方法：

void addReq(Requirement req){
    try {
        ReqFamily pReqParent = (ReqFamily) selectedNode.getData();
        req.setParent(pReqParent);
        req.addInDB();//here i want to catch it 


        DefaultTreeNode newReqNode = new DefaultTreeNode(req,selectedNode);
        if (pReqParent!=null){
            pReqParent.addRequirement(req);
        }

    } catch (Exception ex){

        ex.printStackTrace();
    }
}

Answer 1

试试这个：

        try {
            req.addInDB();//here i want to catch it 
        } catch (Exception ex){
            ex.printStackTrace();
        }

Answer 2

抓住或抛出Exception的不良做法。如果您使用的任何代码抛出已检查的异常，则只捕获该特定异常，并尝试最小化try-catch块的大小。

class MyException extends Exception {
    ...

public void addInDB() throws MyException {
    if (isInBase()){
        throw new MyException ("[ReqFamily->addInDB] requirment already in base");
    }
    ...

void addReq(Requirement req){
    ReqFamily pReqParent = (ReqFamily) selectedNode.getData();
    req.setParent(pReqParent);

    try {
        req.addInDB();
    } catch (MyException ex){
        ex.printStackTrace();
    }

    DefaultTreeNode newReqNode = new DefaultTreeNode(req,selectedNode);
    if (pReqParent!=null){
        pReqParent.addRequirement(req);
    }
}

Answer 3

你可以试试这个：

void addReq(Requirement req){
    try {
        ReqFamily pReqParent = (ReqFamily) selectedNode.getData();
        req.setParent(pReqParent);
        req.addInDB();//here i want to catch it 


        DefaultTreeNode newReqNode = new DefaultTreeNode(req,selectedNode);
        if (pReqParent!=null){
            pReqParent.addRequirement(req);
        }

    } catch (Exception ex){

        JOptionPane.showMessageDialog(null, ex);
    }
}

如果您想捕获要在显示中显示的所有堆栈跟踪，您可以使用：

catch (Exception ex) {

   String
   ls_exception = "";

   for (StackTraceElement lo_stack : ex.getStackTrace()) {

      ls_exception += "\t"+lo_stack.toString()+"\r\n";

   }

   JOptionPane.showMessageDialog(null, ls_exception);
}

如何在调用类中捕获抛出的异常

3 个答案: