Java 利用反射将父类值赋给子类

Java 利用反射将父类值赋给子类

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• A.java

import java.io.Serializable;
import java.util.Set;

public class A implements Serializable {

    private static final long serialVersionUID = 7315556175038040238L;
    private String a;
    private String b;
    private Set<String>  names;

    public String getA() {
        return a;
    }

    public void setA(String a) {
        this.a = a;
    }

    public String getB() {
        return b;
    }

    public void setB(String b) {
        this.b = b;
    }

    public Set<String> getNames() {
        return names;
    }

    public void setNames(Set<String> names) {
        this.names = names;
    }
}

• B.java

import java.io.Serializable;

public class B extends A implements Serializable {
    private static final long serialVersionUID = 2726509261628857907L;
    private String c;
    private String d;

    public String getC() {
        return c;
    }

    public void setC(String c) {
        this.c = c;
    }

    public String getD() {
        return d;
    }

    public void setD(String d) {
        this.d = d;
    }
}

• Demo.java

import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;

public class Demo {
    public static void main(String[] args) throws Exception {
        A a=new A();
        B b=new B();
        List<String> strings = new ArrayList<>();
        strings.add("111");
        strings.add("2323");
        a.setNames(new HashSet<String>(strings));
        a.setA("a");
        a.setB("b");
        fatherToChild(a,b);
        b.getNames().forEach(System.out::println);
        System.out.println(b.getA());
    }

    public static <T>void fatherToChild(T father,T child) throws Exception {
        if (child.getClass().getSuperclass()!=father.getClass()){
            throw new Exception("child 不是 father 的子类");
        }
        Class<?> fatherClass = father.getClass();
        Field[] declaredFields = fatherClass.getDeclaredFields();
        for (int i = 0; i < declaredFields.length; i++) {

            Field field=declaredFields[i];
            System.out.println(field.toGenericString());
            //防止序列化字段报错
            if(field.toGenericString().contains("final")){
                continue;
            }
            Method method=fatherClass.getDeclaredMethod("get"+upperHeadChar(field.getName()));
            Object obj = method.invoke(father);
            field.setAccessible(true);
            field.set(child,obj);
        }

    }

    /**
     * 首字母大写，in:deleteDate，out:DeleteDate
     */
    public static String upperHeadChar(String in) {
        String head = in.substring(0, 1);
        String out = head.toUpperCase() + in.substring(1, in.length());
        return out;
    }
}