Spring Unit Test and object re-injection - spring

Question

In Spring what is the best way to run a bunch of test methods on an object but reset/re-inject the object before each new test method invocation?
I have tried to do in the code below but with my current logic the object gets created and injected only once..
package com.bidtracker;
import org.junit.Test;
import org.junit.runner.RunWith;
import static org.junit.Assert.*;
import static org.hamcrest.CoreMatchers.is;
import com.bidtracker.iface.BidTracker;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
#RunWith(SpringJUnit4ClassRunner.class)
#ContextConfiguration
public class BidTrackerTest {
#Autowired
BidTracker tracker;
#Test
public void shouldReturnHighestBidAmount1(){
tracker.bidOnItem("itemB", "user1", 105);
assertThat(tracker.getHighestBid("itemB").getAmount(),is(Integer.valueOf(105)));
}
#Test
public void shouldReturnHighestBidAmount2(){
tracker.bidOnItem("itemB", "user1", 39);
tracker.bidOnItem("itemB", "user1", 50);
assertThat(tracker.getHighestBid("itemB").getAmount(),is(Integer.valueOf(50)));
}
}

Answer 1

The issue here is that Spring test support by default caches the application context and will reuse the cached context if elements of the key match up(context name(s), active profiles etc). To ask Spring to remove the context from the cache you can mark the test with #DirtiesContext annotation (at the method level or test class level).

Answer 2

JUnit has the #Before annotation, you can use that to do any initialization before each test.
However, I am curious about your case. Here's from the #Test documentation:
The Test annotation tells JUnit that the public void method to which
it is attached can be run as a test case. To run the method, JUnit
first constructs a fresh instance of the class then invokes the
annotated method. Any exceptions thrown by the test will be reported
by JUnit as a failure. If no exceptions are thrown, the test is
assumed to have succeeded.
I'm guessing that the issue is that the bean is a singleton. It actually gets injected again, but if it's been modified you're using the same thing. You can try the #DirtiesContext annotation.