Use the Java library reflection tool to generate dynamic code generation

Use the Java library reflection tool to generate dynamic code generation Reflection is a powerful feature in Java. It allows us to dynamically check the class, methods and attributes at runtime, and can dynamically create objects, call methods and access attributes at runtime.The Java class library provides a wealth of reflection tools, allowing us to use the reflex function to generate dynamic code. In Java, we can use the class and interfaces in the java.lang.reflet package to complete the reflection operation.Below we will introduce some common usage of how to use reflex tools for dynamic code. 1. Get category information and instantiated objects: You can obtain category information with class classes, including class names, methods, attributes, etc.You can use the class.Forname () method to obtain the Class object according to the class name, and then use the newInstance () method to create an object instance. Class<?> cls = Class.forName("com.example.MyClass"); MyClass obj = (MyClass) cls.newInstance(); 2. Calling method: You can obtain a class method information through the Method class and call the method through the Invoke () method.You can use the GetMethod () method to obtain the Method object according to the method name and parameter type. Method method = cls.getMethod("methodName", String.class, int.class); method.invoke(obj, "param1", 10); 3. Access attributes: You can obtain the attribute information of the class through the FIELD class, and access the attributes through the get () and set () methods.You can use the getField () method to obtain the FIELD object according to the attribute name. Field field = cls.getField("fieldName"); Object value = field.get(obj); field.set(obj, newValue); 4. Dynamic proxy: Use the Proxy class to dynamically generate the proxy class, and dynamically handle the call of the object method during runtime. MyInterface obj = new MyInterfaceImpl(); MyInterface proxy = (MyInterface) Proxy.newProxyInstance( obj.getClass().getClassLoader(), new Class<?>[] { MyInterface.class }, new InvocationHandler() { @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { // Add additional processing logic here return method.invoke(obj, args); } }); By using the reflection tool in the Java class library, we can dynamically generate code at runtime to achieve more flexible and dynamic programming.The reflection tool provides us with strong capabilities, but also needs to pay attention to the performance and safety issues during use.