请帮忙检查下访问存储卡的代码

[zwtchy123]

1、建目录 zhj目录已有
String strDirName = System.getProperty("fileconn.dir.memorycard") + "zhj/";
FileConnection fConn = null;
try {
fConn = (FileConnection)Connector.open(strDirName,Connector.READ_WRITE );
if(!fConn.exists())
fConn.create();
}....
2写文件
String strFileName = System.getProperty("fileconn.dir.memorycard") + "zhj/test.txt";
FileConnection fConn = null;
OutputStream out = null;
try {
fConn = (FileConnection)Connector.open(strFileName,Connector.READ_WRITE);
if(!fConn.exists()){
fConn.create();
}
out = fConn.openOutputStream();
out.write("abcdef科技大厦1楼".getBytes("UTF-8"));
out.flush();
}....
3读文件
String strFileName = System.getProperty("fileconn.dir.memorycard") + "zhj/test.txt";
FileConnection fConn = null;
InputStream in = null;
try {
fConn = (FileConnection)Connector.open(strFileName, Connector.READ);
in = fConn.openInputStream();
byte buf[] = new byte[(int)fConn.fileSize()];
in.read(buf);
String str = new String(buf,"UTF-8");
}....
报错，请大虾给看一下！！！

[kf156]

1、建目录 zhj目录已有
String strDirName = System.getProperty("fileconn.dir.memorycard") + "zhj/";
FileConnection fConn = null;
try {
fConn = (FileConnection)Connector.open(strDirName,Connector.READ_WRITE );
if(!fConn.exists())
fConn.create(); //建目录用mkdir() 方法
}....