应用服务和模板方法擦出的火花
原文 PDF：
应用服务 和 模板方法 擦出的火花.pdf（已转文字 + 提取配图）
正文
2023/3/24 00:14
geekhalo geekhalo 2021-09-10 09:05
# 1 # 1 #DDD 5 # 1 # 4
0.
"" ""
1.
2.
1.
DDD
image
1.
2.
3.
4.
""
1.1 UserApplication
UserApplication
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public interface UserApplication {
void createAndEnableUser(CreateAndEnableUserContext context);
void modifyUserName(ModifyUserNameContext context);
}
1. createAndEnableUser "" ""
2. modifyUserName
1.2 UserV1Application
UserV1Application
UserV1Application
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@Service
public class UserV1Application implements UserApplication {
private static final Logger LOGGER = LoggerFactory.getLogger(UserV1Application.class)
@Autowired
private UserRepository userRepository;
@Autowired
private ApplicationEventPublisher eventPublisher;
@Override
@Transactional(readOnly = false)
public void createAndEnableUser(CreateAndEnableUserContext context){
try {
// 1.
User user = User.create(context.getName(), context.getAge());
// 2.
user.enable();
// 3.
this.userRepository.save(user);
// 4.
user.foreachEvent(this.eventPublisher::publishEvent);
// 5.
user.clearEvents();
LOGGER.info("success to handle createAndEnableUser and sync {} to DB", user);
}catch (Exception e){
LOGGER.error("failed to handle createAndEnableUser", e);
if (e instanceof RuntimeException){
throw (RuntimeException) e;
}
throw new RuntimeException(e);
}
}
@Override
@Transactional(readOnly = false)
public void modifyUserName(ModifyUserNameContext context){
try {
// 1.
User user = this.userRepository.getById(context.getUserId());
// 2.
if (user == null){
throw new UserNotFoundException(context.getUserId());
}
// 3.
user.modifyUserName(context.getNewName());
// 4.
this.userRepository.save(user);
// 5.
user.foreachEvent(this.eventPublisher::publishEvent);
// 6.
user.clearEvents();
LOGGER.info("success to handle modifyUserName and sync {} to DB", user);
}catch (Exception e){
LOGGER.error("failed to handle modifyUserName", e);
if (e instanceof RuntimeException){
throw (RuntimeException) e;
}
throw new RuntimeException(e);
}
}
}
UserV1Application
1.
2.
3.
a. Repository
b.
c.
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d. Repository
e. & ApplicationEventPublisher
f.
g.
h. Repository
i. & ApplicationEventPublisher
User Email
@Service
public class EmailApplication {
private static final Logger LOGGER = LoggerFactory.getLogger(EmailApplication.class);
@Autowired
private EmailRepository emailRepository;
@Autowired
private ApplicationEventPublisher eventPublisher;
@Transactional(readOnly = false)
public void createEmail(CreateEmailContext context){
try {
// 1.
Email email = Email.create(context.getUserId(), context.getEmail());
// 2.
email.init();
// 3.
this.emailRepository.save(email);
// 4.
email.foreachEvent(this.eventPublisher::publishEvent);
// 5.
email.clearEvents();
LOGGER.info("success to handle createEmail and sync {} to DB", email);
}catch (Exception e){
LOGGER.error("failed to handle createEmail", e);
if (e instanceof RuntimeException){
throw (RuntimeException) e;
}
throw new RuntimeException(e);
}
}
@Transactional(readOnly = false)
public void modifyEmail(ModifyEmailContext context){
try {
// 1.
Email email = this.emailRepository.getByUserId(context.getUserId());
// 2.
if (email == null){
throw new UserNotFoundException(context.getUserId());
}
// 3.
email.modifyEmail(context.getEmail());
// 4.
this.emailRepository.save(email);
// 5.
email.foreachEvent(this.eventPublisher::publishEvent);
// 6.
email.clearEvents();
LOGGER.info("success to handle modifyEmail and sync {} to DB", email);
}catch (Exception e){
LOGGER.error("failed to handle modifyEmail", e);
if (e instanceof RuntimeException){
throw (RuntimeException) e;
}
throw new RuntimeException(e);
}
}
}
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""
""
2.
image
1.
""
2. ""
3. ""
""
1. AbstractDomainService
AbstractCreateService AbstractUpdateService
"" ""
2. AbstractCreateService
3. AbstractUpdateService
AbstractDomainService
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abstract class AbstractDomainService<AGG extends Agg, CONTEXT extends DomainServiceContex
private static final Logger LOGGER = LoggerFactory.getLogger(AbstractDomainService.cl
private final ApplicationEventPublisher eventPublisher;
private final CrudRepository<AGG, ?> repository;
public AbstractDomainService(CrudRepository<AGG, ?> repository,
ApplicationEventPublisher eventPublisher) {
this.eventPublisher = eventPublisher;
this.repository = repository;
}
@Transactional(readOnly = false)
public void handle(CONTEXT context){
try {
//
AGG agg = doHandle(context);
// DB
save2DB(agg);
//
publishAndCleanEvent(agg);
//
onSuccess(agg, context);
}catch (Exception e){
//
onException(e, context);
}
}
/**
*
* @param context
* @return
*/
protected abstract AGG doHandle(CONTEXT context);
/**
*
* @param e
* @param context
*/
protected void onException(Exception e, CONTEXT context){
LOGGER.error("failed to handle {}", context, e);
if (e instanceof RuntimeException){
throw (RuntimeException) e;
}
throw new RuntimeException(e);
}
/**
*
* @param agg
* @param context
*/
protected void onSuccess(AGG agg, CONTEXT context){
LOGGER.info("success to handle {} and sync {} to DB", context, agg);
}
/**
*
* @param agg
*/
private void publishAndCleanEvent(AGG agg){
// 1.
agg.foreachEvent(this.eventPublisher::publishEvent);
// 2.
agg.clearEvents();
}
/**
* DB
* @param agg
*/
private void save2DB(AGG agg){
this.repository.save(agg);
}
}
AbstractDomainService
doHandle
AbstractCreateService
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public abstract class AbstractCreateService<AGG extends Agg, CONTEXT extends DomainServic
extends AbstractDomainService<AGG, CONTEXT>{
public AbstractCreateService(CrudRepository<AGG, ?
> repository, ApplicationEventPublisher eventPublisher) {
super(repository, eventPublisher);
}
/**
*
* @param context
* @return
*/
@Override
protected AGG doHandle(CONTEXT context) {
// 1.
AGG agg = instance(context);
// 2.
update(agg, context);
return agg;
}
/**
*
* @param agg
* @param context
*/
protected void update(AGG agg, CONTEXT context){
}
/**
*
* @param context
* @return
*/
protected abstract AGG instance(CONTEXT context);
}
AbstractCreateService instance
update
AbstractUpdateService
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public abstract class AbstractUpdateService<AGG extends Agg, CONTEXT extends DomainServic
extends AbstractDomainService<AGG, CONTEXT>{
public AbstractUpdateService(CrudRepository<AGG, ?> repository,
ApplicationEventPublisher eventPublisher) {
super(repository, eventPublisher);
}
/**
*
* @param context
* @return
*/
@Override
protected AGG doHandle(CONTEXT context) {
// 1.
AGG agg = loadAgg(context);
// 2.
if (agg == null){
notFound(context);
}
// 3.
update(agg, context);
return agg;
}
/**
*
* @param context
* @return
*/
protected abstract AGG loadAgg(CONTEXT context);
/**
*
* @param context
*/
protected abstract void notFound(CONTEXT context);
/**
*
* @param agg
* @param context
*/
protected abstract void update(AGG agg, CONTEXT context);
}
AbstractUpdateService
CreateAndEnableUserService
@Service
public class CreateAndEnableUserService
extends AbstractCreateService<User, CreateAndEnableUserContext> {
@Autowired
public CreateAndEnableUserService(ApplicationEventPublisher eventPublisher, CrudRepos
> repository) {
super(repository, eventPublisher);
}
@Override
protected User instance(CreateAndEnableUserContext context) {
// User
return User.create(context.getName(), context.getAge());
}
@Override
protected void update(User agg, CreateAndEnableUserContext context) {
//
agg.enable();
}
}
ModifyUserNameService
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@Service
public class ModifyUserNameService extends AbstractUpdateService<User, ModifyUserNameCont
private final JpaRepository<User, Long> repository;
public ModifyUserNameService(JpaRepository<User, Long> repository, ApplicationEventPu
super(repository, eventPublisher);
this.repository = repository;
}
@Override
protected User loadAgg(ModifyUserNameContext context) {
//
return this.repository.getById(context.getUserId());
}
@Override
protected void notFound(ModifyUserNameContext context) {
//
throw new UserNotFoundException(context.getUserId());
}
@Override
protected void update(User agg, ModifyUserNameContext context) {
//
agg.modifyUserName(context.getNewName());
}
}
image
@Service
public class UserV2Application implements UserApplication {
@Autowired
private CreateAndEnableUserService createAndEnableUserService;
@Autowired
private ModifyUserNameService modifyUserNameService;
@Override
public void createAndEnableUser(CreateAndEnableUserContext context) {
//
this.createAndEnableUserService.handle(context);
}
@Override
public void modifyUserName(ModifyUserNameContext context) {
//
this.modifyUserNameService.handle(context);
}
}
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@Service
public class UserV2Application2
implements UserApplication {
@Autowired
private JpaRepository<User, Long> repository;
@Autowired
private ApplicationEventPublisher applicationEventPublisher;
@Override
public void createAndEnableUser(CreateAndEnableUserContext context) {
//
new AbstractCreateService<User, CreateAndEnableUserContext>
(this.repository, applicationEventPublisher){
@Override
protected User instance(CreateAndEnableUserContext context) {
return User.create(context.getName(), context.getAge());
}
@Override
protected void update(User agg, CreateAndEnableUserContext context) {
agg.enable();
}
}.handle(context);
}
@Override
public void modifyUserName(ModifyUserNameContext context) {
//
new AbstractUpdateService<User, ModifyUserNameContext>
(this.repository, this.applicationEventPublisher){
@Override
protected void update(User agg, ModifyUserNameContext context) {
agg.modifyUserName(context.getNewName());
}
@Override
protected void notFound(ModifyUserNameContext context) {
throw new UserNotFoundException(context.getUserId());
}
@Override
protected User loadAgg(ModifyUserNameContext context) {
return repository.getById(context.getUserId());
}
}.handle(context);
}
}
4. Spring
Spring Template
JdbcTemplate RedisTemplate
Spring JdbcTemplate
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public User getByName(String name) {
String sql = "select " +
"id, create_time, update_time, status, name, password " +
"from tb_user " +
"where " +
"name = ?";
List<User> result = jdbcTemplate.query(sql, new Object[]
{name}, new RowMapper<User>() {
@Override
public User mapRow(ResultSet resultSet, int i) throws SQLException {
Long idForSelect = resultSet.getLong(1);
java.sql.Date createDate = resultSet.getDate(2);
java.sql.Date updateDate = resultSet.getDate(3);
Integer statusCode = resultSet.getInt(4);
String name = resultSet.getString(5);
String password = resultSet.getString(6);
User user = new User();
user.setId(idForSelect);
user.setCreateTime(createDate);
user.setUpdateTime(updateDate);
user.setStatus(UserStatus.valueOfCode(statusCode));
user.setName(name);
user.setPassword(password);
return user;
}
});
return result.isEmpty() ? null : result.get(0);
}
JdbcTemplate jdbc +
Spring
1.
2. Spring
3. Spring
4. Spring
https://mp.weixin.qq.com/s/Ya0x1jsS7jU0nrD9Calt8w 11/18
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public final class ApplicationServiceTemplate<AGG extends Agg> {
private static final Logger LOGGER = LoggerFactory.getLogger(ApplicationServiceTempla
private final ApplicationEventPublisher eventPublisher;
private final CrudRepository<AGG, ?> repository;
public ApplicationServiceTemplate(ApplicationEventPublisher eventPublisher,
CrudRepository<AGG, ?> repository) {
this.eventPublisher = eventPublisher;
this.repository = repository;
}
public <CONTEXT extends DomainServiceContext> void executeCreate(CONTEXT context,
Function<CONTEXT, AG
BiConsumer<CONTEXT,
{
try {
// 1.
AGG agg = instanceFun.apply(context);
// 2.
updateFun.accept(context, agg);
// 3.
save2DB(agg);
publishAndCleanEvent(agg);
onSuccess(agg, context);
}catch (Exception e){
onException(e, context);
}
}
public <CONTEXT extends DomainServiceContext> void executeUpdate(CONTEXT context,
Function<CONTEXT, AG
Consumer<CONTEXT> no
BiConsumer<CONTEXT,
{
try {
// 1.
AGG agg = loadFun.apply(context);
// 2.
if (agg == null){
notFoundFun.accept(context);
}
// 3.
updateFun.accept(context, agg);
publishAndCleanEvent(agg);
onSuccess(agg, context);
}catch (Exception e){
onException(e, context);
}
}
private <CONTEXT extends DomainServiceContext> void onException(Exception e, CONTEXT
LOGGER.error("failed to handle {}", context, e);
if (e instanceof RuntimeException){
throw (RuntimeException) e;
}
throw new RuntimeException(e);
}
private <CONTEXT extends DomainServiceContext> void onSuccess(AGG agg, CONTEXT contex
LOGGER.info("success to handle {} and sync {} to DB", context, agg);
}
private void publishAndCleanEvent(AGG agg){
// 1.
agg.foreachEvent(this.eventPublisher::publishEvent);
// 2.
agg.clearEvents();
}
private void save2DB(AGG agg){
this.repository.save(agg);
}
}
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@Service
public class UserV3Application
implements UserApplication {
private final JpaRepository<User, Long> repository;
private final ApplicationServiceTemplate<User> applicationServiceTemplate;
@Autowired
public UserV3Application(ApplicationEventPublisher eventPublisher, JpaRepository<User
this.repository = repository;
this.applicationServiceTemplate = new ApplicationServiceTemplate<>(eventPublisher
}
@Override
public void createAndEnableUser(CreateAndEnableUserContext cxt) {
this.applicationServiceTemplate.executeCreate(cxt,
context -> User.create(context.getName(), context.getAge()),
(createAndEnableUserContext, user) -> user.enable()
);
}
@Override
public void modifyUserName(ModifyUserNameContext cxt) {
this.applicationServiceTemplate.executeUpdate(cxt,
context -> repository.getById(context.getUserId()),
context -> {throw new UserNotFoundException(context.getUserId());},
(modifyUserNameContext, user) -> user.modifyUserName(modifyUserNameCo
);
}
}
1.
2.
3. null
5. + Builder
Builder Builder
API
Spring Spring
Builder
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public abstract class BaseV4Application {
private static final Logger LOGGER = LoggerFactory.getLogger(BaseV4Application.class)
@Autowired
private ApplicationEventPublisher eventPublisher;
/**
* Creator
* @param repository
* @param <A>
* @param <CONTEXT>
* @return
*/
protected <A extends Agg, CONTEXT extends DomainServiceContext> Creator<A, CONTEXT> c
> repository){
return new Creator<A, CONTEXT>(repository);
}
/**
* Updater
* @param aggregateRepository
* @param <A>
* @param <CONTEXT>
* @return
*/
protected <A extends Agg, CONTEXT extends DomainServiceContext> Updater<A, CONTEXT> u
> aggregateRepository){
return new Updater<A, CONTEXT>(aggregateRepository);
}
/**
* Builder
* 1.
* 2.
* @param <A>
* @param <CONTEXT>
*/
protected class Creator<A extends Agg, CONTEXT extends DomainServiceContext>{
//
private final CrudRepository<A, ?> aggregateRepository;
//
private Function<CONTEXT, A> instanceFun;
//
private BiConsumer<A, CONTEXT> successFun = (agg, context)->{
LOGGER.info("success to handle {} and sync {} to DB", context, agg);
};
//
private BiConsumer<Exception, CONTEXT> errorFun = (exception, context) -> {
LOGGER.error("failed to handle {}", context, exception);
if (exception instanceof RuntimeException){
throw (RuntimeException) exception;
}
throw new RuntimeException(exception);
};
//
private BiConsumer<A, CONTEXT> updateFun = (a, context) -> {};
Creator(CrudRepository<A, ?> aggregateRepository) {
Preconditions.checkArgument(aggregateRepository != null);
this.aggregateRepository = aggregateRepository;
}
/**
*
* @param instanceFun
* @return
*/
public Creator<A, CONTEXT> instance(Function<CONTEXT, A> instanceFun){
Preconditions.checkArgument(instanceFun != null);
this.instanceFun = instanceFun;
return this;
}
/**
*
* @param updater
* @return
*/
public Creator<A, CONTEXT> update(BiConsumer<A, CONTEXT> updater){
Preconditions.checkArgument(updater != null);
this.updateFun = this.updateFun.andThen(updater);
return this;
}
/**
*
* @param onSuccessFun
* @return
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*/
public Creator<A, CONTEXT> onSuccess(BiConsumer<A, CONTEXT> onSuccessFun){
Preconditions.checkArgument(onSuccessFun != null);
this.successFun = onSuccessFun.andThen(this.successFun);
return this;
}
/**
*
* @param errorFun
* @return
*/ errorFun){
public Creator<A, CONTEXT> onError(BiConsumer<Exception, CONTEXT>
Preconditions.checkArgument(errorFun != null);
this.errorFun = errorFun.andThen(this.errorFun);
return this;
}
/**
*
* @param context
* @return
*/
public A call(CONTEXT context){
Preconditions.checkArgument(this.instanceFun != null, "instance fun can not b
Preconditions.checkArgument(this.aggregateRepository != null, "aggregateRepos
A a = null;
try{
//
a = this.instanceFun.apply(context);
//
this.updateFun.accept(a, context);
// DB
this.aggregateRepository.save(a);
//
if (eventPublisher != null){
// 1.
a.foreachEvent(eventPublisher::publishEvent);
// 2.
a.clearEvents();
}
//
this.successFun.accept(a, context);
}catch (Exception e){
//
this.errorFun.accept(e, context);
}
return a;
}
}
/**
* Builder
* 1.
* 2.
* @param <A>
* @param <CONTEXT>
*/
protected class Updater<A extends Agg, CONTEXT extends DomainServiceContext> {
//
private final CrudRepository<A, ?> aggregateRepository;
// DB
private Function<CONTEXT, A> loadFun;
//
private Consumer<CONTEXT> onNotExistFun = context -> {};
//
private BiConsumer<A, CONTEXT> successFun = (agg, context)->{
LOGGER.info("success to handle {} and sync {} to DB", context, agg);
};
//
private BiConsumer<Exception, CONTEXT> errorFun = (exception, context) -> {
LOGGER.error("failed to handle {}", context, exception);
if (exception instanceof RuntimeException){
throw (RuntimeException) exception;
}
throw new RuntimeException(exception);
};
//
private BiConsumer<A, CONTEXT> updateFun = (a, context) -> {};
Updater(CrudRepository<A, ?> aggregateRepository) {
this.aggregateRepository = aggregateRepository;
}
/**
* DB
* @param loader
* @return
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*/
public Updater<A, CONTEXT> loader(Function<CONTEXT, A> loader){
Preconditions.checkArgument(loader != null);
this.loadFun = loader;
return this;
}
/**
*
* @param updateFun
* @return
*/
public Updater<A, CONTEXT> update(BiConsumer<A, CONTEXT> updateFun){
Preconditions.checkArgument(updateFun != null);
this.updateFun = updateFun.andThen(this.updateFun);
return this;
}
/**
*
* @param onSuccessFun
* @return
*/
public Updater<A, CONTEXT> onSuccess(BiConsumer<A, CONTEXT> onSuccessFun){
Preconditions.checkArgument(onSuccessFun != null);
this.successFun = onSuccessFun.andThen(this.successFun);
return this;
}
/**
*
* @param errorFun
* @return
*/ errorFun){
public Updater<A, CONTEXT> onError(BiConsumer<Exception, CONTEXT>
Preconditions.checkArgument(errorFun != null);
this.errorFun = errorFun.andThen(this.errorFun);
return this;
}
/**
*
* @param onNotExistFun
* @return
*/
public Updater<A, CONTEXT> onNotFound(Consumer<CONTEXT> onNotExistFun){
Preconditions.checkArgument(onNotExistFun != null);
this.onNotExistFun = onNotExistFun.andThen(this.onNotExistFun);
return this;
}
/**
*
* @param context
* @return
*/
public A call(CONTEXT context){
Preconditions.checkArgument(this.aggregateRepository != null, "aggregateRepos
Preconditions.checkArgument(this.loadFun != null, "loader can not both be nul
A a = null;
try {
// DB
a = this.loadFun.apply(context);
if (a == null){
//
this.onNotExistFun.accept(context);
}
//
updateFun.accept(a, context);
//
this.aggregateRepository.save(a);
//
if (eventPublisher != null){
// 1.
a.foreachEvent(eventPublisher::publishEvent);
// 2.
a.clearEvents();
}
//
this.successFun.accept(a, context);
}catch (Exception e){
//
this.errorFun.accept(e, context);
}
return a;
}
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}
}
Creator Updater
1. Builder
2. ""
@Service
public class UserV4Application
extends BaseV4Application
implements UserApplication {
@Autowired
private JpaRepository<User, Long> repository;
@Override
public void createAndEnableUser(CreateAndEnableUserContext context) {
this.<User, CreateAndEnableUserContext>creatorFor(this.repository)
//
.instance(createAndEnableUserContext -
> User.create(createAndEnableUserContext.getName(), createAndEnableUserContext.getAge()))
//
.update((user, createAndEnableUserContext) -> user.enable())
//
.call(context);
}
@Override
public void modifyUserName(ModifyUserNameContext context) {
this.<User, ModifyUserNameContext>updaterFor(repository)
//
.loader(domainServiceContext -
> this.repository.getById(domainServiceContext.getUserId()))
//
.onNotFound(modifyUserNameContext -
> {throw new UserNotFoundException(modifyUserNameContext.getUserId());})
//
.update((user, modifyUserNameContext) -
> user.modifyUserName(modifyUserNameContext.getNewName()))
//
.call(context);
}
}
DDD
Spring + Builder
+
+Buil builder + +
der
"" ""
kali wifi
Raymond
https://mp.weixin.qq.com/s/Ya0x1jsS7jU0nrD9Calt8w 17/18
2023/3/24 00:14 K8s-1.25
10ES10
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配图
第 1 页 — 001-p01.png
第 18 页 — 002-p18.jpeg
