[ch05] UserServiceTx using dynamic proxy.

src/main/java/ch01/springbook/user/TransactionHandler.java

@@ -0,0 +1,52 @@
+package ch01.springbook.user;
+
+import java.lang.reflect.InvocationHandler;
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+
+import org.springframework.transaction.PlatformTransactionManager;
+import org.springframework.transaction.TransactionStatus;
+import org.springframework.transaction.support.DefaultTransactionDefinition;
+
+public class TransactionHandler implements InvocationHandler {
+
+	private Object target;
+	private PlatformTransactionManager transactionManager;
+	private String pattern;
+
+	public void setTarget(Object target) {
+		this.target = target;
+	}
+
+	public void setTransactionManager(PlatformTransactionManager transactionManager) {
+		this.transactionManager = transactionManager;
+	}
+
+	public void setPattern(String pattern) {
+		this.pattern = pattern;
+	}
+
+	public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
+
+		if (method.getName().startsWith(pattern)) {
+			return invokeInTransaction(method, args);
+		} else {
+			return method.invoke(target, args);
+		}
+	}
+
+	private Object invokeInTransaction(Method method, Object[] args) throws Throwable {
+
+		TransactionStatus status = transactionManager.getTransaction(new DefaultTransactionDefinition());
+
+		try {
+			Object ret = method.invoke(target, args);
+			transactionManager.commit(status);
+			return ret;
+
+		} catch (InvocationTargetException e) {
+			transactionManager.rollback(status);
+			throw e.getTargetException();
+		}
+	}
+}

src/test/java/ch01/springbook/user/UserServiceTest.java

@@ -7,6 +7,7 @@
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.fail;
 
+import java.lang.reflect.Proxy;
 import java.util.Arrays;
 import java.util.List;
 
@@ -135,6 +136,35 @@ public void upgradeAllOrNothing() throws Exception {
 		checkLevelUpgraded(userList.get(1), false);
 	}
 
+	@Test
+	public void upgradeAllOrNothingUsingDynamicProxy() throws Exception {
+
+		TestUserService testUserService = new TestUserService(userList.get(3).getId());
+		testUserService.setUserDao(userDao);
+
+		TransactionHandler txHandler = new TransactionHandler();
+		txHandler.setTarget(testUserService);
+		txHandler.setTransactionManager(transactionManager);
+		txHandler.setPattern("upgradeLevels");
+
+		UserService txUserService = (UserService)Proxy.newProxyInstance(
+			getClass().getClassLoader(), new Class[] { UserService.class }, txHandler);
+
+		userDao.deleteAll();
+		for (User user : userList) {
+			userDao.add(user);
+		}
+
+		try {
+			txUserService.upgradeLevels();
+			fail("TestUserServiceException expected.");
+		} catch (TestUserServiceException e) {
+
+		}
+
+		checkLevelUpgraded(userList.get(1), false);
+	}
+
 	private void checkLevelUpgraded(User user, boolean upgraded) {
 
 		User userUpdate = userDao.get(user.getId());