什么是使用JUnit @BeforeClass和Spring @TestExecutionListener beforeTestClass（的TestContext的TestContext） “钩子” 之间的区别？ 如果是有区别的，这什么情况下使用哪一个？
Maven依赖关系：
弹簧核心：3.0.6.RELEASE
弹簧上下文：3.0.6.RELEASE
弹簧试验：3.0.6.RELEASE
弹簧数据公共核心：1.2.0.M1
弹簧数据的mongodb：1.0.0.M4
蒙戈的Java驱动程序：2.7.3
JUnit的：4.9
CGLIB：2.2
使用JUnit @BeforeClass注释：
import org.junit.BeforeClass;
import org.junit.Test;
import org.junit.Assert;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.AbstractJUnit4SpringContextTests;
@ContextConfiguration(locations = { "classpath:test-config.xml" })
public class TestNothing extends AbstractJUnit4SpringContextTests {
@Autowired
PersonRepository repo;
@BeforeClass
public static void runBefore() {
System.out.println("@BeforeClass: set up.");
}
@Test
public void testInit() {
Assert.assertTrue(repo.findAll().size() == 0 );
}
}
=> @BeforeClass: set up.
=> Process finished with exit code 0
使用弹簧钩：
（1）重写beforeTestClass（TextContext的TestContext）：
import org.springframework.test.context.TestContext;
import org.springframework.test.context.support.AbstractTestExecutionListener;
public class BeforeClassHook extends AbstractTestExecutionListener {
public BeforeClassHook() { }
@Override
public void beforeTestClass(TestContext testContext) {
System.out.println("BeforeClassHook.beforeTestClass(): set up.");
}
}
（2）使用@TestExecutionListeners注释：
import org.springframework.test.context.TestExecutionListeners;
// other imports are the same
@ContextConfiguration(locations = { "classpath:test-config.xml" })
@TestExecutionListeners(BeforeClassHook.class)
public class TestNothing extends AbstractJUnit4SpringContextTests {
@Autowired
PersonRepository repo;
@Test
public void testInit() {
Assert.assertTrue(repo.findAll().size() == 0 );
}
}
=> BeforeClassHook.beforeTestClass(): set up.
=> Process finished with exit code 0
