一、获取Method
- 继承的方法Method无法反射,会被编译器强制执行,因此反射一个类的方法时不考虑父类的方法,只考虑当前类的方法
1. 常用方法
- 参考:Method 类常用方法
- Class.getMethod(String name,Class…parameterTypes);
根据方法名称和相关参数,来定位需要查找的Method对象并返回,parameterTypes:Method的参数类型的列表(参数顺序需按声明Method时的参数列表排列)
- Class.getMethods();
获取所有public方法,包括类自身声明的public方法、父类中的public方法、实现的接口方法
- Class.getDeclaredMethod(String name, Class… parameterTypes);
返回一个Method对象,反映此Class对象所表示的类或接口的指定已声明方法
- Class.getDeclaredMethods();
获取本类中所有方法,包括类自身的方法、重写的父类的方法、实现的接口方法
2. 测试用例
public class User {
public int id;
private String name;
String address;
protected int sno;
public User() {
}
public User(int id, String name, String address, int sno) {
super();
this.id = id;
this.name = name;
this.address = address;
this.sno = sno;
}
public void study() {
System.out.println("study...");
}
public void eat(int a,String b) {
System.out.println("eat...");
}
@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", address=" + address + ", sno=" + sno + "]";
}
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((address == null) ? 0 : address.hashCode());
result = prime * result + id;
result = prime * result + ((name == null) ? 0 : name.hashCode());
result = prime * result + sno;
return result;
}
@Override
public boolean equals(Object obj) {
if (this == obj)
return true;
if (obj == null)
return false;
if (getClass() != obj.getClass())
return false;
User other = (User) obj;
if (address == null) {
if (other.address != null)
return false;
} else if (!address.equals(other.address))
return false;
if (id != other.id)
return false;
if (name == null) {
if (other.name != null)
return false;
} else if (!name.equals(other.name))
return false;
if (sno != other.sno)
return false;
return true;
}
}
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
public class Test {
public static void main(String[] args) throws Exception {
Class usrClass = Class.forName("com.lzj.reflect.pojo.User");
Method[] methods = usrClass.getDeclaredMethods();
for(Method method : methods){
System.out.println(Modifier.toString(method.getModifiers()));
System.out.println(method.getReturnType().getSimpleName());
System.out.println(method.getName());
Class[] parameterTypes = method.getParameterTypes();
for(Class parameterType : parameterTypes){
System.out.println(parameterType.getSimpleName());
}
}
}
}
二、反编译Method
import java.lang.reflect.Method;
import java.lang.reflect.Modifier;
public class Test {
public static void main(String[] args) throws Exception {
StringBuilder s = new StringBuilder();
Class userClass = Class.forName("com.lzj.reflect.pojo.User");
s.append(Modifier.toString(userClass.getModifiers()) + " class "+userClass.getSimpleName()+" {\n");
Method[] methods = userClass.getDeclaredMethods();
for(Method method : methods){
s.append("\t");
s.append(Modifier.toString(method.getModifiers()));
s.append(" ");
s.append(method.getReturnType().getSimpleName());
s.append(" ");
s.append(method.getName());
s.append("(");
Class[] parameterTypes = method.getParameterTypes();
for(Class parameterType : parameterTypes){
s.append(parameterType.getSimpleName());
s.append(",");
}
if(parameterTypes.length > 0) {
s.deleteCharAt(s.length() - 1);
}
s.append("){}\n");
}
s.append("}");
System.out.println(s);
}
}