本文将叙述如何运行时查看类信息，其中包括变量，方法，以及通过反射修改变量，执行方法等
包括如何反射匿名内部类及如何执行其方法，但是笔者强烈不建议这么做，这里只是演示反射而已
下面是一个测试类
[java]
package reflect;
public class Outer {
static{
System.out.println("Testing..");
}
TestInterface ti = new TestInterface() {
public String test() {
return "this is ti";
}
};
public Outer(String name){
System.out.println("Outer");
}
public String toString(){
System.out.println("Outer toString");
return new TestInterface() {
public String test() {
return "this is a test!";
}
}.test();
}
@SuppressWarnings("unused")
private void privateMethod(){
System.out.println("privateMethod");
}
protected void protectedMethod(){
System.out.println("protectedMethod");
}
void packageMethod(){
System.out.println("packageMethod");
}
public static void staticMethod(){
System.out.println("staticMethod");
}
public interface TestInterface {
public String test();
}
public static class StaticInner {
private static final String TAG = "StaticInnerTAG";
public StaticInner(){
System.out.println("StaticInner");
}
public String toString(){
return TAG;
}
}
private class Inner{
String name;
public Inner(){
System.out.println("Inner");
}
public Inner(String name){
System.out.println("reflect.Outer.Inner.Inner(String name)");
this.name = name;
}
}
}
其中包括了普通内部类，静态内部类，内部匿名类，接口等
其中外部类Outer没有默认构造器，String reflect.Outer.Inner.getName()是private的……
外部类
Constructor,Method,Class.forName,newInstance
下面来看如何对上述的类进行反射
首先先看外部类Outer
[java]
public static void main(String[] args) {
try {
Class< > outer = Class.forName("reflect.Outer");
outer = Outer.class;
Constructor< >[] constructors = outer.getConstructors();
for (Constructor< > constructor : constructors) {
Class< >[] types = constructor.getParameterTypes();
System.out.println(constructor.getName() + "(" + arrayToString(types) + ")");
}
Constructor< > outerConstructor = outer.getConstructor(String.class);
Outer outerInstance = (Outer) outerConstructor.newInstance("a outer");
System.out.println(outerInstance);
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SecurityException e) {
e.printStackTrace();
} catch (NoSuchMethodException e) {
e.printStackTrace();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (InstantiationException e) {
e.printStackTrace();
} catch (IllegalAccessException e) {
e.printStackTrace();
} catch (InvocationTargetException e) {
e.printStackTrace();
}
}
public static String arrayToString(Class< >[] classes){
StringBuilder stringBuilder = new StringBuilder();
for (Class< > type : classes) {
stringBuilder.append(type.getCanonicalName());
stri