fix 长度问题

src/main/java/com/sunyard/util/ParamChecker.java

@@ -91,7 +91,7 @@ public final class ParamChecker {
      * @throws IllegalArgumentException 如果 str 为 null 或仅包含空白字符
      */
     public static String checkNotBlank(String str, String paramName) {
-        if (str == null || str.isBlank()) {
+        if (str == null || !str.trim().isEmpty()) {
             throw new IllegalArgumentException("参数 '" + paramName + "' 不能为 null、空字符串或仅包含空白字符");
         }
         return str;

src/main/java/racal/sunyard/main/SydApi4j.java

@@ -6791,6 +6791,8 @@ public class SydApi4j implements SydApi {
 
     }
 
+
+
     @Override
     public String SM2EncryptOrder(byte[] publicKey, byte[] pOrgData) {
         Proto77 proto = new Proto77();
@@ -6917,10 +6919,8 @@ public class SydApi4j implements SydApi {
         // 重新计算长度
         int len = bb.position();
         len -= 2;
-        byte[] lenArray = new byte[2];
+        bb.put(0, (byte) ((len >> 8) & 0xFF));                 // 覆盖开头的两个占位字节
-        lenArray[0] = (byte) ((len >> 8) & 0xFF);
+        bb.put(1, (byte) (len & 0xFF));                 // 覆盖开头的两个占位字节
-        lenArray[1] = (byte) (len & 0xFF);
-        bb.put(lenArray);
 
         // 通信
         synchronized (this) {
@@ -6955,6 +6955,133 @@ public class SydApi4j implements SydApi {
 
 
 
+
+    /**
+     * SM2 解密（支持大包分段）
+     * @param privateKey 私钥字节数组
+     * @param pCipherData 密文数据
+     * @return 解密后的明文
+     */
+    public byte[] SYD_SM2Decrypt(byte[] privateKey, byte[] pCipherData) {
+        ParamChecker.checkNotNull(privateKey, "privateKey");
+        ParamChecker.checkNotNull(pCipherData, "pCipherData");
+
+        final int CHUNK_SIZE = 63 * 1024; // 63 KB，与加密保持一致
+        int dataLen = pCipherData.length;
+        int offset = 0;
+
+        // 1. 分块传入密文
+        while (offset < dataLen) {
+            int len = Math.min(CHUNK_SIZE, dataLen - offset);
+            SYD_SM2Decrypt(1, privateKey, ByteBuffer.wrap(pCipherData, offset, len), offset);
+            offset += len;
+        }
+
+        // 2. 传入私钥，触发解密处理
+        SYD_SM2Decrypt(2, privateKey, null, 0);
+
+        // 3. 分块取回明文
+        int idx = 0;
+        List<ByteBuffer> chunks = new ArrayList<>();
+        int totalLen = 0;
+        int isLast = 0;
+
+        while (isLast != 1) {
+            MutiReturn7 ret = SYD_SM2Decrypt(3, null, null, idx);
+            ByteBuffer bb = ret.getData();
+            isLast = ret.getIsLast();
+
+            if (bb != null && bb.remaining() > 0) {
+                chunks.add(bb);
+                totalLen += bb.remaining();
+                idx += bb.remaining();
+            } else if (isLast != 1) {
+                throw new RuntimeException("Empty plain chunk with isLast=0");
+            }
+        }
+
+        // 合并明文分片
+        byte[] result = new byte[totalLen];
+        int offset2 = 0;
+        for (ByteBuffer chunk : chunks) {
+            int len = chunk.remaining();
+            chunk.get(result, offset2, len);
+            offset2 += len;
+        }
+        return result;
+    }
+
+    /**
+     * 底层解密通信（与加密结构对称，魔法数改为 "7G"）
+     * @param dataType 1-传入密文块，2-传入私钥，3-取明文块
+     * @param privateKey 私钥（dataType=2时使用）
+     * @param pCipherData 密文块（dataType=1时使用）
+     * @param idx 偏移量索引
+     * @return MutiReturn7 包含返回码、isLast标志及数据片
+     */
+    private MutiReturn7 SYD_SM2Decrypt(int dataType, byte[] privateKey, ByteBuffer pCipherData, int idx) {
+        ParamChecker.checkInRange(dataType, "dataType", 1, 3);
+
+        // 估算缓存大小
+        int buffLen = 4096;
+        if (dataType == 1) {
+            buffLen = pCipherData.limit() > 4096 ? 64 * 1024 : 5 * 1024;
+        }
+
+        ByteBuffer bb = ByteBuffer.allocate(buffLen);
+        PacketSN sn = PacketSN.gen();
+        bb.put(new byte[2]);                 // 占位，后续填总长度
+        bb.put(sn.getSn().array());
+        bb.put("7G".getBytes());             // 魔法数改为 "7G"
+        bb.put((byte) dataType);
+
+        if (dataType == 2) {                 // 私钥
+            bb.put(ByteUtil.shortToBytes((short) privateKey.length));
+            bb.put(privateKey);
+        }
+        if (dataType == 1) {                 // 密文块
+            bb.put(ByteUtil.shortToBytes((short) pCipherData.limit()));
+            bb.put(pCipherData);
+            bb.put(ByteUtil.shortToBytes((short) idx));
+        }
+        if (dataType == 3) {                 // 请求明文块
+            bb.put(ByteUtil.shortToBytes((short) (63 * 1024)));
+            bb.put(ByteUtil.shortToBytes((short) idx));
+        }
+
+        // 填写总长度（长度字段本身不包含在内）
+        int len = bb.position() - 2;
+        bb.put(0, (byte) ((len >> 8) & 0xFF));                 // 覆盖开头的两个占位字节
+        bb.put(1, (byte) (len & 0xFF));                 // 覆盖开头的两个占位字节
+
+        // 通信
+        synchronized (this) {
+            bb = syncRead(syncSend(bb));
+        }
+
+        bb.flip();
+        bb.position(12);                     // 跳过前12字节（头部固定）
+        byte[] code = new byte[2];
+        bb.get(code);
+        int retCode = Integer.parseInt(new String(code));
+        if (retCode != 0) {
+            throw new SydApiException(retCode);
+        }
+
+        // 仅 dataType=3 时有数据返回
+        if (dataType == 3) {
+            int isLast = bb.get();
+            byte[] dataLenArr = new byte[2];
+            bb.get(dataLenArr);
+            int dataLen = ByteUtil.bytesToInt(dataLenArr);
+            ByteBuffer slice = ByteBufferUtil.sliceAndConsume(bb, dataLen);
+            return new MutiReturn7(retCode, isLast, slice);
+        } else {
+            return new MutiReturn7(retCode, 0, null);
+        }
+    }
+
+
     @Override
     public String SM2Encrypt(byte[] publicKey, byte[] pOrgData) {
         Proto77 proto = new Proto77();