PropertyAccess/ClassPropertyAdapter/PropertyAdapter of Tapestry5

看了三个接口说明，简要记下三者的关系：
1、PropertyAccess中的get/set方法是用于读取/设置某对象instance中的某属性property，比较明了，另外还有个方法getAdapter是用于获取此对象class或者实例instance的ClassPropertyAdapter对象。
2、而在得到ClassPropertyAdapter后，也可以与PropertyAccess中的get/set方法一样操作一个instance中的property，另外有个方法getPropertyAdapter则根据参数propertyName获取PropertyAdapter对象。
3、在得到PropertyAdapter对象之后，也同前二个接口一样可以传入instance实例，对此实例的propertyName进行get/set操作。其中有个方法getClassAdapter则是反过来用于获取ClassPropertyAdapter对象，以操作此对象的其他属性。

reflect permission and security manage in java

import java.lang.reflect.Field;
import java.lang.reflect.ReflectPermission;

public class ReflectField {

private String test = "test string in class ReflectField!";

public static void main(String[] args) throws Exception {
Class ref = ReflectField.class;

SecurityManager nsm = new SecurityManager();
System.setSecurityManager(nsm);
ReflectPermission rp = new ReflectPermission("suppressAccessChecks", null);
System.out.println(rp);
// java.security.AccessControlException:
// access denied (java.lang.reflect.ReflectPermission suppressAccessChecks
// nsm.checkPermission(rp);
SecurityManager sm = System.getSecurityManager();
System.out.println(sm);

Field[] fields = ref.getDeclaredFields();
System.out.println(fields.length);
for (Field field : fields) {
// java.security.AccessControlException:
// access denied (java.lang.reflect.ReflectPermission suppressAccessChecks
// field.setAccessible(true);

// java.lang.IllegalArgumentException
// at sun.reflect.UnsafeFieldAccessorImpl.ensureObj(UnsafeFieldAccessorImpl.java)
// System.out.println(field.get(ref));

System.out.println(field.getName());
}

}

}

This main method had set a security manage to this java application, in order to prevent java reflect get and set private fields.

how to protect private field from reflect get and set in java

public class ReflectField {

protected String test = "test string in class ReflectField!";

}


/**
* subclass of ReflectField
*/
import java.lang.reflect.Field;

public class ReflectExtendsField extends ReflectField {

// protected String test = "test string in class ReflectExtendsField!";
private String test = "test string in class ReflectExtendsField!";

public static void main(String[] args) throws Exception {
// Class ref = Class.forName("ReflectExtendsField");
Class ref = ReflectExtendsField.class;

Field[] fields = ref.getFields();
System.out.println(fields.length);
for (Field field : fields) {
field.setAccessible(true);
System.out.println(field.get(ref));
}

Field testField = ref.getDeclaredField("test");
testField.setAccessible(true);
System.out.println(testField);
System.out.println(testField.get(ref));
}
}

It is just a hack, and usally protect private field from access using security manage.