Java反射(关于数组)

已知条件：

类型A，A中有数组类型的字段

结果：

将A中的数组类型字段实例化

 

 

public class A {

    private B[] bs;

    public A() {

    }

    /**
     * @return the bs
     */
    public B[] getBs() {
        return bs;
    }

    /**
     * @param bs the bs to set
     */
    public void setBs(B[] bs) {
        this.bs = bs;
    }
}

 

public class B {

    private String s;

    public B() {

    }

    public B(String s) {
        this.s = s;
    }

    /**
     * @return the s
     */
    public String getS() {
        return s;
    }

    /**
     * @param s the s to set
     */
    public void setS(String s) {
        this.s = s;
    }
}

 

即：将A中的bs实例化，但bs这个名字不是预先知道的

 

public class TestRef {

    /**
     * @param args
     */
    public static void main(String[] args) throws Exception {

        A a = new A();

        Field field = a.getClass().getDeclaredField("bs");



        System.out.println(field.getType());

        Class cls = field.getType();

        Class c1 = cls.getComponentType();

//        B b = (B) cls.newInstance();

        String name = c1.getName();
//        System.out.println(name);

        Class c = Class.forName(name);
        Object o = c.newInstance();


        Object b = Array.newInstance(c1, 2);

        Array.set(b, 0, c.newInstance());
        Array.set(b, 1, c.newInstance());

//

//        c.newInstance();


        Method method = a.getClass().getDeclaredMethod("setBs", cls);

//        B[] bs = new B[2];

//        bs[0] = new B("1111");

//        bs[1] = new B("22222222");


        method.invoke(a, b);

        System.out.println(a.getBs()[0].getS());
        System.out.println(a.getBs()[1].getS());
    }

}