对J2EE中的DAO组件编写单元测试(3)

　public abstract class TransactionCallback {
public final Object  execute() throws Exception {
Transaction tx =  HibernateUtil.getCurrentSession().beginTransaction();
try {
Object r =  doInTransaction();
tx.commit();
return r;
}
catch(Exception e) {
tx.rollback();
throw e;
}
}
// 模板方法： 
protected abstract Object  doInTransaction() throws Exception;
}

　public class DatabaseFixture {
private static Server  server = null; // 持有HSQLDB的实例 
private static final  String DATABASE_NAME = "javaeedev"; // 数据库名称 
private static final  String SCHEMA_FILE = "schema.sql"; // 数据库初始化脚本 
private static final  List initSqls = new ArrayList();
　@BeforeClass // 启动HSQLDB数据库 
public static void  startDatabase() throws Exception {
if(server!=null)
return;
server = new  Server();
server.setDatabaseName(0,  DATABASE_NAME);
server.setDatabasePath(0, "mem:" + DATABASE_NAME);
server.setSilent(true);
server.start();
try {
Class.forName("org.hsqldb.jdbcDriver");
}
catch(ClassNotFoundException cnfe) {
throw new  RuntimeException(cnfe);
}
LineNumberReader  reader = null;
try {
reader = new  LineNumberReader(new  　
InputStreamReader(DatabaseFixture.class.getClassLoader()
.getResourceAsStream(SCHEMA_FILE)));
for(;;) {
String line =  reader.readLine();
if(line==null) break;
// 将text类型的字段改为varchar(2000)，因为HSQLDB不支持text： 
line =  line.trim().replace(" text ", " varchar(2000)  ").replace(" 　
text,", " varchar(2000),");
if(!line.equals(""))
initSqls.add(line);
}
}
catch(IOException e)  {
throw new  RuntimeException(e);
}
finally {
if(reader!=null)  {
try {  reader.close(); } catch(IOException e) {}
}
}
}
　@Before // 执行初始化脚本 
public void initTables()  {
for(String sql :  initSqls) {
executeSQL(sql);
}
}
static Connection  getConnection() throws SQLException {
return  DriverManager.getConnection("jdbc:hsqldb:mem:" + DATABASE_NAME,  
"sa", "");
}
static void  close(Statement stmt) {
if(stmt!=null) {
try {
stmt.close();
}
catch(SQLException e) {}
}
}
static void  close(Connection conn) {
if(conn!=null) {
try {
conn.close();
}
catch(SQLException e) {}
}
}
static void  executeSQL(String sql) {
Connection conn =  null;
Statement stmt =  null;
try {
conn =  getConnection();
boolean  autoCommit = conn.getAutoCommit();
conn.setAutoCommit(true);
stmt = conn.createStatement();
stmt.execute(sql);
conn.setAutoCommit(autoCommit);
}
catch(SQLException e)  {
log.warn("Execute failed: " + sql + "\nException: "  + e.getMessage());
}
finally {
close(stmt);
close(conn);
}
}
public static Object  createProxy(final Object target) {
return  Proxy.newProxyInstance(
target.getClass().getClassLoader(),
target.getClass().getInterfaces(),
new  InvocationHandler() {
public  Object invoke(Object proxy, final Method method, final Object[] args) 
throws  Throwable {
return new TransactionCallback() {
@Override
protected Object doInTransaction() throws Exception {
return method.invoke(target, args);
}
}.execute();
}
}
);
}
}