Use the CGLIB FULL framework to achieve high -efficiency programming skills in the Java class library
Use the CGLIB FULL framework to achieve high -efficiency programming skills in the Java class library
Overview:
During the development of Java, in order to improve the performance and maintenance of the code, developers often use various techniques and tools.The CGLIB FULL framework is a commonly used tool in the Java class library. It can help us achieve some efficient programming skills and improve the efficiency and quality of code.This article will introduce some common features and use skills of the CGLIB FULL framework, and provide the corresponding Java code example.
Introduction to CGLIB FULL framework
The CGLIB FULL framework is a code generating library based on the ASM framework. It can dynamically generate the byte code of the Java class during runtime.Compared with the Java native reflection mechanism, the CGLIB FULL framework has higher performance and flexibility, which can be used to achieve some specific programming needs.
2. Common features and uses of the CGLIB FULL framework
1. Dynamic proxy
The CGLIB FULL framework provides a dynamic proxy function, which can be used to generate proxy objects at runtime, and then implement AOP programming and other functions.The proxy object generated through the CGLIB FULL framework can be called before and after the target object method, such as log records and transaction management.
The following is an example code that uses the CGLIB FULL framework to implement dynamic proxy:
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import net.sf.cglib.proxy.Enhancer;
public class DynamicProxyExample {
public static void main(String[] args) {
Enhancer enhancer = new Enhancer();
enhancer.setSuperclass(RealObject.class);
enhancer.setCallback(new MethodInterceptor() {
@Override
public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
System.out.println("Before method");
Object result = proxy.invokeSuper(obj, args);
System.out.println("After method");
return result;
}
});
RealObject realObject = (RealObject) enhancer.create();
realObject.doSomething();
}
static class RealObject {
public void doSomething() {
System.out.println("Doing something");
}
}
}
In the above code, we created a dynamic proxy object through the Enhancer class, set the target object to the RealObject class, and add customized processing logic to the method interceptor.When calling the method of the proxy object, first execute the processing logic of the interceptor, and then use the method of calling the target object with MethodProxy.
2. Bytecode enhancement
The CGLIB FULL framework allows us to modify the existing bytecodes of the class to achieve some specific needs.You can modify the byte code to achieve functions similar to code injection and behavior modification.
The following is a sample code that uses the CGLIB FULL framework to enhance bytecode enhancement:
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;
import java.lang.reflect.Method;
public class EnhanceClassExample {
public static void main(String[] args) {
Enhancer enhancer = new Enhancer();
enhancer.setSuperclass(RealObject.class);
enhancer.setCallback(new MethodInterceptor() {
@Override
public Object intercept(Object obj, Method method, Object[] args, MethodProxy proxy) throws Throwable {
System.out.println("Before method " + method.getName());
Object result = proxy.invokeSuper(obj, args);
System.out.println("After method " + method.getName());
return result;
}
});
RealObject realObject = (RealObject) enhancer.create();
realObject.doSomething();
}
static class RealObject {
public void doSomething() {
System.out.println("Doing something");
}
}
}
In the above code, we also use the Enhancer class to create a dynamic proxy object, and set the target object as the RealObject class.In the method interceptor, we add some of the processing logic of the print log to each method.By calling the method of the proxy object, we can see that the corresponding logic will be executed before and after the method call.
3. Summary
This article introduces some common features and use skills of the CGLIB FULL framework, and provides corresponding Java code examples.By using the CGLIB FULL framework, we can realize the functions of dynamic proxy and bytecode enhancement to improve the performance and flexibility of the code, thereby achieving efficient programming.In actual development, we can choose the appropriate function of the CGLIB FULL framework according to specific needs and scenes.
