转发：J2ME FileConnection开发

下面是对开发J2ME FileConnection的一些总结：
1、J2ME FileConnection在WTK能正常运行，但拿到S60可能会报错，因他们之间存在差异。


3、在WTK能用fc.exists()来判断文件是否存在，但在S60中会抛出异常，创建文件如下：



Java代码
private void createFile(String fileName) {  
    String fileExt = "";  
    {  
        int idx = fileName.lastIndexOf('.');  
        if (idx > 0) {  
            fileExt = fileName.substring(idx, fileName.length());  
            fileName = fileName.substring(0, idx);  
        }  
    }  
    try {  
        currDir = (FileConnection) Connector.open("file:///" + currDirName  
                + fileName + fileExt, Connector.WRITE);  
        currDir.create();  
    }catch (SecurityException e) {   
        Alert alert = new Alert("Error!", "Can not access/delete file " 
                + fileName + " in directory " + currDirName  
                + "\nException: " + e.getMessage(), null, AlertType.ERROR);  
        alert.setTimeout(Alert.FOREVER);  
        FileMIDlet.display.setCurrent(alert);             
    }catch (IOException e) {  
        e.printStackTrace();  
        try {  
            currDir = (FileConnection) Connector.open("file:///" 
                    + currDirName + fileName + "(" + genId() + ")" 
                    + fileExt, Connector.WRITE);  
            currDir.create();  
        } catch (IOException e1) {  
            // TODO Auto-generated catch block  
            currDir = null;  
        }  
    }  
} 

private void createFile(String fileName) {
String fileExt = "";
{
int idx = fileName.lastIndexOf('.');
if (idx > 0) {
fileExt = fileName.substring(idx, fileName.length());
fileName = fileName.substring(0, idx);
}
}
try {
currDir = (FileConnection) Connector.open("file:///" + currDirName
+ fileName + fileExt, Connector.WRITE);
currDir.create();
}catch (SecurityException e) {
Alert alert = new Alert("Error!", "Can not access/delete file "
+ fileName + " in directory " + currDirName
+ "\nException: " + e.getMessage(), null, AlertType.ERROR);
alert.setTimeout(Alert.FOREVER);
FileMIDlet.display.setCurrent(alert);
}catch (IOException e) {
e.printStackTrace();
try {
currDir = (FileConnection) Connector.open("file:///"
+ currDirName + fileName + "(" + genId() + ")"
+ fileExt, Connector.WRITE);
currDir.create();
} catch (IOException e1) {
// TODO Auto-generated catch block
currDir = null;
}
}
}



4、S60无法浏览JAD，JAD文件，保存JAD或JAR时也会抛出“writing to the file is not allowed”异常，解决办法是加个后缀名，如：yongmail.jad.重命名
5、有些手机不支持文件系统，所以最好用接口方式

6、 解决java.lang.SecurityException: Access denied，可用上面的例子！

7、测试文件系统时，最好用真机





导读
手机中的重定向问题及处理 http://fonter.iteye.com/blog/400836
J2ME如何通过cmwap直接访问互连网 http://fonter.iteye.com/blog/400868
J2ME开发中由WAP网关带来的cookie问题 http://fonter.iteye.com/blog/399105
安装JAD时提示JAD无效原因之一 http://fonter.iteye.com/blog/400888
J2ME网络交互之优化 http://fonter.iteye.com/blog/405137
解决Eclipse无法调试J2ME程序的配置方法 http://fonter.iteye.com/blog/405697

J2ME飞信协议分析(初稿) http://fonter.iteye.com/blog/408385

转发：http://fonter.iteye.com/blog/441946