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();

}

}

);

}

}