本論文提出一個可選擇擷取等級，並依此等級從Java class中將重要的程式資訊擷取出來之工具：jExtractor。jExtractor可以從Java class中，將重要的部分Code擷取出來並存入智慧卡內，以保護該重要部分的安全性，而其他剩餘之部分則保留下來。jExtractor亦可再從智慧卡中將Code取出，並與原被擷取後剩餘之部分合併，還原為原本可執行的Java class。我們使用了86808個Java class來實驗測試jExtractor，其中81.7068%可以順利將class中所有的method、local variables及global variables擷取出來存入Mifare Standard S50非接觸式智慧卡中；而若只擷取class中最大的method與其local variables，則可以順利存入S50卡片的比例為94.3104%。最後，結合行動代理人與jExtractor，提出一個於車資通訊中緊急救援應用之模擬實作。 We develop a tool, called jExtractor, to extract the private code part of a Java class in a configurable way. Then the extracted part can be serialized and stored into a Mifare Standard 1K contactless smart card by jExtractor. When a user needs to use this Java class, jExtractor can be used to load the private code part from smart card and merge it with the remaining part of the class to be the original one. Moreover, we use 86808 Java classes for testing the jExtractor. Code parts of 81.7% Java classes can be extracted and preserved in Mifare Standard S50 (1K) smart cards. We implement a mobile agent with the jExtractor to simulate seeking for an emergency rescue for drivers in telematics.
