Struts2 使用拦截器更改表单字段

Question

I am newbie in struts2. In interceptor how can i change value of form field and then submitting it to database? For example when user enters firstName value in form then when it submits i want to change firstName and then submit it to database.

Here is my interceptor's code

public class TestInterceptor extends AbstractInterceptor implements Interceptor
{

    @Override
    public String intercept(ActionInvocation actionInvocation) throws Exception
    {

        ValueStack stack = actionInvocation.getStack();

        Map<String, Object> params = ActionContext.getContext().getParameters();
        Set<String> keys = params.keySet();

        System.out.println(keys + " " + stack.size());

        /*
         * for (String key : keys)
         * {
         * String[] value = (String[]) params.get(key);
         * System.out.println(value.length + " , " + value[0]);
         * }
         */
        Map<String, Object> context = new HashMap<String, Object>();
        context.put("firstNames", "Changed");
        context.put("firstName", "Changed");
        stack.setParameter("firstName", "Changeds");
        stack.push(context);

        String result = actionInvocation.invoke();

        return result;
    }
}

Answer 1

In your code simply you need to change value in the map. no need to put any other context.

Map<String, Object> params = actionInvocation.getInvocationContext().getParameters();
params.put("firstName", "Changed");

Answer 2

Try this:

public String intercept(ActionInvocation invocation) throws Exception {
    final ActionContext context = invocation.getInvocationContext();
    Map<String,Object> parameters = (Map<String,Object>)context.get(ActionContext.PARAMETERS);

    Map<String, Object> parametersCopy = new HashMap<String, Object>();
    parametersCopy.putAll(parameters);
    parametersCopy.put("myParam", "changedValue");

    context.put(ActionContext.PARAMETERS, parametersCopy);

    return invocation.invoke();
}