动态JPA查询不起作用

Question

I am using join query through createQuery in JPA. I have 2 tables MasterScrip and OrderMaster . Entity code is given below. The dynamic query is returning collection object. I debugged and found that the query executes and returns collection object correctly; but, after the object returned an error, shown below:

   [javax.xml.bind.JAXBException: class [Ljava.lang.Object; nor any of its super class is known to this context.]
    javax.xml.ws.WebServiceException: javax.xml.bind.MarshalException...

    SEVERE: Error Rendering View[/ClientTemplate/orderReport.xhtml]
    javax.el.ELException: /ClientTemplate/orderReport.xhtml @14,142 value="#{stockOrderBean.scripLst}": com.sun.xml.ws.streaming.XMLStreamReaderException: unexpected XML tag. expected: {http://service/}getOrderScripByUserNameResponse but found: {http://schemas.xmlsoap.org/soap/envelope/}Envelope
        at com.sun.faces.facelets.el.TagValueExpression.getValue(TagValueExpression.java:114)

Stateless bean method:

 public Collection<MasterScrip> getOrderScripByUserName(String userName)
{        
    try
    {
        String squery = "select DISTINCT(s.scripSymbol),s.scripID from MasterScrip s,OrderStock o where o.scripID.scripID = s.scripID and o.userName.userName = '" + userName + "'";
        Collection<MasterScrip> c = em.createQuery(squery).getResultList();
        //UserMaster um = em.find(UserMaster.class,userName);
        return c;
    } catch(Exception e) {
        System.out.println(e);
        return null;
    }
}

What is the cause of this error? How do I solve it?

Answer 1

First, as noted in the comments, you should always use parameters instead of concatenating parameter values:

select DISTINCT(s.scripSymbol), s.scripID from MasterScrip s, OrderStock o 
where o.scripID.scripID = s.scripID and o.userName.userName = :userName

This would prevent SQL injection attacks, or simply incorrect queries in case of a user name like O'Reilly for example.

Your query returns two different columns. There is no way for such a query to magically return instances of MasterScrip . It returns a List<Object[]> , where each Object[] contains two values: the scripSymbol and the scripID .

The query would return instances of MasterScrip if it was

select distinct s from MasterScrip s, OrderStock o 
where o.scripID.scripID = s.scripID and o.userName.userName = :userName