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大小: 9KB文件類型: .rar金幣: 2下載: 1 次發(fā)布日期: 2021-06-24
- 語言: Java
- 標簽:
資源簡介
Java提供了一套機制來動態(tài)執(zhí)行方法和構(gòu)造方法，以及數(shù)組操作等，這套機制就叫——反射。反射機制是如今很多流行框架的實現(xiàn)基礎(chǔ)，其中包括Spring、Hibernate等。原理性的問題不是本文的重點，接下來讓我們在實例中學(xué)習(xí)這套精彩的機制。
1. 得到某個對象的屬性
public Object getProperty(Object owner, String fieldName) throws Exception {
Class ownerClass = owner.getClass();
Field field = ownerClass.getField(fieldName);
Object property = field.get(owner);
return property;
}
Class ownerClass = owner.getClass()：得到該對象的Class。
Field field = ownerClass.getField(fieldName)：通過Class得到類聲明的屬性。
Object property = field.get(owner)：通過對象得到該屬性的實例，如果這個屬性是非公有的，這里會報IllegalAccessException。
2. 得到某個類的靜態(tài)屬性
public Object getStaticProperty(String className, String fieldName)
throws Exception {
Class ownerClass = Class.forName(className);
Field field = ownerClass.getField(fieldName);
Object property = field.get(ownerClass);
return property;
}
Class ownerClass = Class.forName(className) ：首先得到這個類的Class。
Field field = ownerCla
代碼片段和文件信息
package?com.hexiang.reflection;
import?java.lang.reflect.Array;????????
import?java.lang.reflect.Constructor;????????
import?java.lang.reflect.Field;????????
import?java.lang.reflect.Method;????????
???????
???????
/**??????
?*?Java?Reflection?Cookbook??????
?*??????
?*?@author?Michael?Lee??????
?*?@since?2006-8-23??????
?*?@version?0.1a??????
?*/???????
???????
public?class?Reflection?{????????
????/**??????
?????*?得到某個對象的公共屬性??????
?????*??????
?????*?@param?owner?fieldName??????
?????*?@return?該屬性對象??????
?????*?@throws?Exception??????
?????*??????
?????*/???????
????public?object?getProperty（object?owner?String?fieldName）?throws?Exception?{????????
????????Classject>?ownerClass?=?owner.getClass（）;????????
???????
????????Field?field?=?ownerClass.getField（fieldName）;????????
???????
????????object?property?=?field.get（owner）;????????
???????
????????return?property;????????
????}????????
???????
????/**??????
?????*?得到某類的靜態(tài)公共屬性??????
?????*??????
?????*?@param?className???類名??????
?????*?@param?fieldName???屬性名??????
?????*?@return?該屬性對象??????
?????*?@throws?Exception??????
?????*/???????
????public?object?getStaticProperty（String?className?String?fieldName）????????
????????????throws?Exception?{????????
????????Class?ownerClass?=?Class.forName（className）;????????
???????
????????Field?field?=?ownerClass.getField（fieldName）;????????
???????
????????object?property?=?field.get（ownerClass）;????????
???????
????????return?property;????????
????}????????
???????
???????
????/**??????
?????*?執(zhí)行某對象方法??????
?????*??????
?????*?@param?owner??????
?????*????????????對象??????
?????*?@param?methodName??????
?????*????????????方法名??????
?????*?@param?args??????
?????*????????????參數(shù)??????
?????*?@return?方法返回值??????
?????*?@throws?Exception??????
?????*/???????
????@SuppressWarnings（“unchecked“）
public?object?invokeMethod（object?owner?String?methodName?object[]?args）????????
????????????throws?Exception?{????????
???????
????????Classject>?ownerClass?=?owner.getClass（）;????????
???????
????????Class[]?argsClass?=?new?Class[args.length];????????
???????
????????for?（int?i?=?0?j?=?args.length;?i?????????????argsClass[i]?=?args[i].getClass（）;????????
????????}????????
???????
????????Method?method?=?ownerClass.getMethod（methodName?argsClass）;????????
???????
????????return?method.invoke（owner?args）;????????
????}????????
???????
???????
??????/**??????
?????*?執(zhí)行某類的靜態(tài)方法??????
?????*??????
?????*?@param?className??????
?????*????????????類名??????
?????*?@param?methodName??????
?????*????????????方法名??????
?????*?@param?args??????
?????*????????????參數(shù)數(shù)組??????
?????*?@return?執(zhí)行方法返回的結(jié)果??????
?????*?@throws?Exception??????
?????*/???????
????@SuppressWarnings（“unchecked“）
public?object?invokeStaticMethod（String?className?String?methodName????????
????????????object[]?args）?throws?Exception?{????????
????????Clas ?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件??????65536??2010-01-07?09:13??Java?反射（Reflection）?經(jīng)典實用例子\Java?反射（Reflection）?經(jīng)典實用例子.doc
?????文件???????5054??2010-01-07?09:12??Java?反射（Reflection）?經(jīng)典實用例子\Reflection.java
?????目錄??????????0??2010-01-07?09:14??Java?反射（Reflection）?經(jīng)典實用例子
-----------?---------??----------?-----??----
????????????????70590????????????????????3
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