Java动态代理三——模拟AOP实现
以下案例模拟AOP实现
目录结构
接口PersonService
package
com.ljq.service;
public
interface
PersonService {
public
void
save(String name);
public
void
update(String name, Integer personId);
public
String getPersonName(Integer personId);
}
实现类PersonServiceBean
package
com.ljq.service.impl;
import
com.ljq.service.PersonService;
public
class
PersonServiceBean
implements
PersonService {
private
String user
=
null
;
public
PersonServiceBean() {
super
();
}
public
PersonServiceBean(String user) {
super
();
this
.user
=
user;
}
public
String getPersonName(Integer personId) {
System.out.println(
"
我是getPersonName()方法
"
);
return
"
get
"
;
}
public
void
save(String name) {
System.out.println(
"
我是save()方法
"
);
}
public
void
update(String name, Integer personId) {
System.out.println(
"
我是update()方法
"
);
}
public
String getUser() {
return
user;
}
public
void
setUser(String user) {
this
.user
=
user;
}
}
动态代理类JDKProxyFactory
package
com.ljq.aop;
import
java.lang.reflect.InvocationHandler;
import
java.lang.reflect.Method;
import
java.lang.reflect.Proxy;
import
com.ljq.service.impl.PersonServiceBean;
public
class
JDKProxyFactory
implements
InvocationHandler {
//
要代理的原始对象
private
Object targer;
/**
* 创建动态代理
*
*
@param
targer 要代理的原始对象
*
@return
*/
public
Object createProxyInstance(Object targer){
this
.targer
=
targer;
return
Proxy.newProxyInstance(
this
.targer.getClass().getClassLoader(),
this
.targer.getClass().getInterfaces(),
this
);
}
public
Object invoke(Object proxy, Method method, Object[] args)
throws
Throwable {
Object result
=
null
;
PersonServiceBean bean
=
(PersonServiceBean)
this
.targer;
if
(bean.getUser()
!=
null
) {
//
前置通知
doBefore();
try
{
result
=
method.invoke(targer, args);
//
后置通知
doAfter();
}
catch
(Exception e) {
//
例外通知
doException();
}
finally
{
//
最终通知
doFinally();
}
}
return
result;
}
private
void
doBefore() {
System.out.println(
"
我是前置通知
"
);
}
private
void
doAfter() {
System.out.println(
"
我是后置通知
"
);
}
private
void
doException() {
System.out.println(
"
我是例外通知
"
);
}
private
void
doFinally() {
System.out.println(
"
我是最终通知
"
);
}
}
动态代理类CGlibProxyFactory：使用CGLIB技术
package
com.ljq.aop;
import
java.lang.reflect.Method;
import
com.ljq.service.impl.PersonServiceBean;
import
net.sf.cglib.proxy.Enhancer;
import
net.sf.cglib.proxy.MethodInterceptor;
import
net.sf.cglib.proxy.MethodProxy;
public
class
CGlibProxyFactory
implements
MethodInterceptor{
private
Object target;
public
Object createProxyInstance(Object target){
this
.target
=
target;
Enhancer enhancer
=
new
Enhancer();
enhancer.setSuperclass(
this
.target.getClass());
//
非final
enhancer.setCallback(
this
);
return
enhancer.create();
}
public
Object intercept(Object proxy, Method method, Object[] args,
MethodProxy methodProxy)
throws
Throwable {
Object result
=
null
;
PersonServiceBean bean
=
(PersonServiceBean)
this
.target;
if
(bean.getUser()
!=
null
){
//
前置通知
doBefore();
try
{
result
=
methodProxy.invoke(target, args);
//
后置通知
doAfter();
}
catch
(Exception e) {
//
例外通知
doException();
}
finally
{
//
最终通知
doFinally();
}
}
return
result;
}
private
void
doBefore() {
System.out.println(
"
我是前置通知
"
);
}
private
void
doAfter() {
System.out.println(
"
我是后置通知
"
);
}
private
void
doException() {
System.out.println(
"
我是例外通知
"
);
}
private
void
doFinally() {
System.out.println(
"
我是最终通知
"
);
}
}
测试类AopTest
package
com.ljq.test;
import
com.ljq.aop.CGlibProxyFactory;
import
com.ljq.aop.JDKProxyFactory;
import
com.ljq.service.PersonService;
import
com.ljq.service.impl.PersonServiceBean;
public
class
AopTest {
public
static
void
main(String[] args) {
proxyTest();
proxyTest2();
}
private
static
void
proxyTest() {
JDKProxyFactory jdkProxyFactory
=
new
JDKProxyFactory();
PersonService personService
=
(PersonService)jdkProxyFactory.
createProxyInstance(
new
PersonServiceBean(
"
zhangsan
"
));
personService.getPersonName(
1
);
}
private
static
void
proxyTest2() {
CGlibProxyFactory cglibProxyFactory
=
new
CGlibProxyFactory();
PersonServiceBean bean
=
(PersonServiceBean)cglibProxyFactory.
createProxyInstance(
new
PersonServiceBean(
"
lisi
"
));
bean.save(
"
a
"
);
}
}
运行结果
