Question

java.lang.NoSuchFieldException: id

The below line is creating the exception.

String fieldValue =String.valueOf(studyplanCategory.getClass().getField(filterProperty).get(studyplanCategory)); 

studyplanCategory is a valid object and has got actual values. Beacuse of this exception the load method and the search function in the LazyLoading DataTable of my JSF webapp is not working.

Answer 1

App fires up this exception because its doesn’t see attribudes your want to give back.
Method getField() return non-private attribudes so if your attribudes are private, method doesn’t see them. You can check http://docs.oracle.com/javase/tutorial/reflect/member/fieldTrouble.html

So you can do that your attribudes will change on protected or public and then should work it right. But this way (its same like example on primefaces) simulate real database.

public List<Car> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String,String> filters) {  
        List<Car> data = new ArrayList<Car>();  

        //filter  
        for(Car car : datasource) {  
            boolean match = true;  

            for(Iterator<String> it = filters.keySet().iterator(); it.hasNext();) {  
                try {  
                    String filterProperty = it.next();  
                    String filterValue = filters.get(filterProperty);  
                    String fieldValue = String.valueOf(car.getClass().getField(filterProperty).get(car));  

...

So this list simulate real database only for example. If you want to use it. so you shoud do it on backing bean class and there do it. You open connection already with some filter or don’t and then return data from database.

//EDIT: Man wrote that you should use getDeclaredField() but i did try this and it didn’t work well, and throws up IlegalAccessException. When a pretype attribudes to protected, it works fine. I don’t know why.