jdk动态代理和CGLIB动态代理的区别：
jdk动态代理只能针对实现了接口的目标代理， CGLIB是针对类来实现动态代理，当没有实现接口的类需要代理时，就需要通过CGLIB来实现动态代理。
jdk动态代理：
User.java
public class User {
private String uname;
private String email;
public String getUname() {
return uname;
}
public void setUname(String uname) {
this.uname = uname;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
}UserDao.java
public interface UserDao {
@Test
public void read(String uname,String email);
@Test
public void write(String uname,String email);
}UserDaoImpl.java
public class UserDaoImpl implements UserDao {
@Override
public void read(String uname, String email) {
System.out.println("read " + uname + "'s Email is :"+email);
}
@Override
public void write(String uname, String email) {
System.out.println("write " + uname + "'s Email is :"+email);
}
}
UserInvocationHandler.java
public class UserInvocationHandler implements InvocationHandler {
private Object obj = null;
public UserInvocationHandler(Object obj){
this.obj = obj;
}
private String getMethodName(Method method){
return method.getName();
}
private Annotation[] getAnnotation(Method method){
return method.getAnnotations();
}
@Override
public Object invoke(Object proxy, Method method, Object[] args)
throws Throwable {
Object result = null;
System.out.println(proxy.getClass().getSimpleName());
System.out.println("begin...");
//获取方法名
String methodName = getMethodName(method);
System.out.println("方法名称："+methodName);
//获取方法上的注解
Annotation[] annotation = getAnnotation(method);
System.out.println("注解名称："+annotation[0].toString());
result = method.invoke(obj, args);
System.out.println("end...");
return result;
}
}
UserTest.java
public class UserTest {
public static void main(String[] args) {
UserDao uDao = new UserDaoImpl();
UserInvocationHandler invocationHandler = new UserInvocationHandler(uDao);
UserDao proxy = (UserDao) Proxy.newProxyInstance(uDao.getClass().getClassLoader(), uDao.getClass().getInterfaces(), invocationHandler);
proxy.write("xuwei", "[email protected]");
proxy.read("xuwei", "[email protected]");
}
}
运行结果：
$Proxy0
begin...
方法名称：write
注解名称：@org.junit.Test(expected=class org.junit.Test$None, timeout=0)
write xuwei's Email is :[email protected]
end...
$Proxy0
begin...
方法名称：read
注解名称：@org.junit.Test(expected=class org.junit.Test$None, timeout=0)
read xuwei's Email is :[email protected]
end...
CGLIB动态代理：
BookDao.java
public interface BookDao {
public void create();
public void query();
public void update();
public void delete();
}BookDaoImpl.java
public class BookDaoImpl implements BookDao{
@Override
public void create() {
System.out.println("create() is running...");
}
@Override
public void query() {
System.out.println("query() is running...");
}
@Override
public void update() {
System.out.println("update() is running...");
}
@Override
public void delete() {
System.out.println("delete() is running...");
}
}MyCglibProxy.java
public class MyCglibProxy implements MethodInterceptor {
public Enhancer enhancer = new Enhancer();
private String name;
public MyCglibProxy(String name) {
this.name = name;
}
@Override
public Object intercept(Object object, Method method, Object[] args,
MethodProxy methodProxy) throws Throwable {
System.out.println("调用的方法是：" + method.getName());
// 对用户进行判断
if (!"boss".equals(name)) {
System.out.println("你没有权限!");
return null;
}
Object result = methodProxy.invokeSuper(object, args);
return null;
}
}
MyProxyFilter.java
public class MyProxyFilter implements CallbackFilter {
@Override
public int accept(Method arg0) {
if (!"query".equalsIgnoreCase(arg0.getName()))
return 0;
return 1;
}
}MyCglibProxyFactory.java
public class MyCglibProxyFactory {
public static BookDaoImpl getProxyInstance(MyCglibProxy myProxy) {
Enhancer en = new Enhancer();
// 进行代理
en.setSuperclass(BookDaoImpl.class);
en.setCallback(myProxy);
// 生成代理实例
return (BookDaoImpl) en.create();
}
public static BookDaoImpl getAuthInstanceByFilter(MyCglibProxy myProxy) {
Enhancer en = new Enhancer();
// 进行代理
en.setSuperclass(BookDaoImpl.class);
en.setCallbacks(new Callback[]{myProxy,NoOp.INSTANCE});
en.setCallbackFilter(new MyProxyFilter());
// 生成代理实例
return (BookDaoImpl) en.create();
}
}MyCglibClient.java
public class MyCglibClient {
public static void main(String[] args) {
BookDaoImpl service = MyCglibProxyFactory.getProxyInstance(new MyCglibProxy("boss"));
service.create();
BookDaoImpl service2 = MyCglibProxyFactory.getProxyInstance(new MyCglibProxy("john"));
service2.create();
BookDaoImpl service3 = MyCglibProxyFactory.getAuthInstanceByFilter(new MyCglibProxy("join"));
service3.create();
BookDaoImpl service4 = MyCglibProxyFactory.getAuthInstanceByFilter(new MyCglibProxy("john"));
service4.query();
}
}运行结果：
调用的方法是：create
create() is running...
调用的方法是：create
你没有权限!
调用的方法是：create
你没有权限!
query() is running...