CAP转换器失败，出现'不受支持的int类型的中间值，必须将值转换为short或byte类型'

Question

我非常接近最后使用命令行为JCDK 2.2.2创建CAP文件。我首先将源文件Transfer.java编译成一个类文件Transfer.class，然后尝试生成CAP文件。一切都很好，只是我试图建立从类文件我的Java小程序卡时，从CAP转换工具得到错误

error: line 56: smartTransfer.Transfer: unsupported int type of intermediate value, must cast intermediate value to type short or byte.

。我不知道这个错误来自哪里，因此无法将该值分配给一个字节或一个字节。

我记得当我用JCDK 3.0.5安装了Eclipse Neon时，出现了一个未知位置的int错误，但小程序仍然运行。我想由于我的系统上的JRE。

这里是我的applet代码：

package smartTransfer; 
import javacard.framework.*; 

public class Transfer extends Applet { 
final static byte CLASS = (byte) 0x80; 
final static byte WRITE_USER_INFO_INS = 0x07; 
final static byte WRITEIT_USER_INFO_INS = 0x08; 
final static byte READ_USER_INFO_INS = 0x09; 
final static byte READIT_USER_INFO_INS = 0x06; 
final static byte SIZE_MEMORY = (short) 127; 
static byte[] memory; 
static byte[] memoryy; 

public static void install(byte[] bArray, short bOffset, byte bLength) throws ISOException { 
    new Transfer().register(); 
    memory = new byte[SIZE_MEMORY]; 
    memoryy = new byte[SIZE_MEMORY]; 
} 

public void process(APDU apdu) 
throws ISOException { 
    if (selectingApplet()) return; 
    byte[] buffer = apdu.getBuffer(); 
    if (buffer[ISO7816.OFFSET_CLA] !=CLASS) { 
     ISOException.throwIt(ISO7816.SW_CLA_NOT_SUPPORTED); 
    } 
    byte ins = buffer[ISO7816.OFFSET_INS]; 
    switch (ins) { 
    case READ_USER_INFO_INS: 
     readUserInfo(apdu); 
     break; 
    case READIT_USER_INFO_INS: 
     readitUserInfo(apdu); 
     break; 
    case WRITE_USER_INFO_INS: 
     writeUserInfo(apdu); 
     break; 
    case WRITEIT_USER_INFO_INS: 
     writeitUserInfo(apdu); 
    default: 
     ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED); 
    } 
} 

private void writeUserInfo(APDU apdu) { 
    byte[] cmd_apdu = apdu.getBuffer(); 
    if (cmd_apdu[ISO7816.OFFSET_P1] != 0x00) 
     ISOException.throwIt(ISO7816.SW_WRONG_P1P2); 
    short offset = (short) (cmd_apdu[ISO7816.OFFSET_P2] & 0x00FF); 
    if (offset >= SIZE_MEMORY) 
     ISOException.throwIt(ISO7816.SW_WRONG_P1P2); 
    short lc = (short)(cmd_apdu[ISO7816.OFFSET_LC] & 0x00FF); 
    if ((offset + lc) > SIZE_MEMORY) 
     ISOException.throwIt(ISO7816.SW_WRONG_LENGTH); 
    if (lc == 0x00) 
     ISOException.throwIt(ISO7816.SW_WRONG_LENGTH); 
    getAPDUBody(apdu);  
     Util.arrayCopy(cmd_apdu, (short)((ISO7816.OFFSET_CDATA) & 0x00FF), 
       memory, offset, lc); 
     ISOException.throwIt(ISO7816.SW_NO_ERROR); 
    } 

public void getAPDUBody(APDU apdu) { 
    byte[] buffer = apdu.getBuffer(); 
    short lc = (short)(buffer[ISO7816.OFFSET_LC] & 0x00FF); 
    if (lc != apdu.setIncomingAndReceive()) 
     ISOException.throwIt(ISO7816.SW_WRONG_LENGTH); 
} 

private void readUserInfo(APDU apdu) { 
    byte[] cmd_apdu = apdu.getBuffer(); 
    if (cmd_apdu[ISO7816.OFFSET_P1] != 0x00) ISOException.throwIt(ISO7816.SW_WRONG_P1P2); 
    short offset = (short) (cmd_apdu[ISO7816.OFFSET_P2] & 0x00FF); 
    if (offset >= SIZE_MEMORY) ISOException.throwIt(ISO7816.SW_WRONG_P1P2); 
    short le = (short)(cmd_apdu[ISO7816.OFFSET_LC] & 0x00FF); 
    if (le == 0x00) le = (short)(SIZE_MEMORY - offset); 
    if ((offset + le) > SIZE_MEMORY) ISOException.throwIt(ISO7816.SW_WRONG_LENGTH); 
    apdu.setOutgoing(); 
    apdu.setOutgoingLength((short)le); 
    apdu.sendBytesLong(memory, (short)offset, (short)le); 

} 

private void writeitUserInfo(APDU apdu) { 
    byte[] cmd_apdu = apdu.getBuffer(); 
    if (cmd_apdu[ISO7816.OFFSET_P1] != 0) 
     ISOException.throwIt(ISO7816.SW_WRONG_P1P2); 
    short offset = (short) (cmd_apdu[ISO7816.OFFSET_P2] & 0x00FF); 
    if (offset >= SIZE_MEMORY) 
     ISOException.throwIt(ISO7816.SW_WRONG_P1P2); 
    short lc = (short)(cmd_apdu[ISO7816.OFFSET_LC] & 0x00FF); 
    if ((offset + lc) > SIZE_MEMORY) 
     ISOException.throwIt(ISO7816.SW_WRONG_LENGTH); 
    if (lc == 0x00) 
     ISOException.throwIt(ISO7816.SW_WRONG_LENGTH); 
    getAPDUBody(apdu);  
     Util.arrayCopy(cmd_apdu, (short)((ISO7816.OFFSET_CDATA) & 0x00FF), 
       memoryy, offset, lc); 
     ISOException.throwIt(ISO7816.SW_NO_ERROR); 
    } 

private void readitUserInfo(APDU apdu) { 
    byte[] cmd_apdu = apdu.getBuffer(); 
    if (cmd_apdu[ISO7816.OFFSET_P1] != 0x00) ISOException.throwIt(ISO7816.SW_WRONG_P1P2); 
    short offset = (short) (cmd_apdu[ISO7816.OFFSET_P2] & 0x00FF); 
    if (offset >= SIZE_MEMORY) ISOException.throwIt(ISO7816.SW_WRONG_P1P2); 
    short le = (short)(cmd_apdu[ISO7816.OFFSET_LC] & 0x00FF); 
    if (le == 0x00) le = (short)(SIZE_MEMORY - offset); 
    if ((offset + le) > SIZE_MEMORY) ISOException.throwIt(ISO7816.SW_WRONG_LENGTH); 
    apdu.setOutgoing(); 
    apdu.setOutgoingLength((short)le); 
    apdu.sendBytesLong(memoryy, (short)offset, (short)le); 

    } 
} 

我知道错误是在第56行，但我想这将是从Transfer.class文件（我无法打开阅读），而不是在源代码中。但是当我读取传入的APDU头时，我能想到的唯一未分配的中间值就是指令案例。

这个错误从哪里来？

Answer 1

该错误已经清楚地告诉你源文件中包含有问题的代码的行。在你的情况下，错误是由所有与if语句

if ((offset + lc) > SIZE_MEMORY) 

的整数类型在这种情况下，中间值是offset + lc线引起的。尽管加号运算符的两个操作数都是短路，但加号运算符的结果是一个int。因此，你需要明确施放此值回一个短：

if ((short)(offset + lc) > SIZE_MEMORY) 

还要注意的是常量SIZE_MEMORY应该可能已经short类型而不是字节：

final static short SIZE_MEMORY = (short) 127;