今天遇到一個問題，在spring配置文件中的id第二個字母不能大寫，否則會產生異常：Bean property 'kManager' is not writable or has an invalid setter method. Did you mean 'KManager'?.為了解決問題研究了一下問題的原因：spring在autoWire的同時用到了jdk提供的java.beans.*目錄下的類(等有時間好好研究一下這些類，功能很強大)，通過它們能夠得到bean的詳細信息。其中有個類PropertyDestriptor類能夠通過bean中的set/get方法找到property，不過有個小前提：property的命名要遵循第二個字母不能大寫。因為java是國外開發的，它對命名遵循了英語的一個規范：大部分的單詞第二個字母都是小寫的，除了URL之類的單詞。
下面的java.beans.Introspector類中通過set/get方法找到property的代碼(希望大家可以自己去看看java.beans.*的代碼)。Open Source! I love it.
/**
* Utility method to take a string and convert it to normal Java variable
* name capitalization. This normally means converting the first
* character from upper case to lower case, but in the (unusual) special
* case when there is more than one character and both the first and
* second characters are upper case, we leave it alone.
* <p>
* Thus "FooBah" becomes "fooBah" and "X" becomes "x", but "URL" stays
* as "URL".
*
* @param name The string to be decapitalized.
* @return The decapitalized version of the string.
*/
public static String decapitalize(String name) {
if (name == null || name.length() == 0) {
return name;
}
if (name.length() > 1 && Character.isUpperCase(name.charAt(1)) &&
Character.isUpperCase(name.charAt(0))){
return name;
}
char chars[] = name.toCharArray();
chars[0] = Character.toLowerCase(chars[0]);
return new String(chars);
}