不在类初始化时就生成 Cipher。

src/main/java/xyz/zhouxy/plusone/commons/security/RSA.java

@@ -1,17 +1,15 @@
 package xyz.zhouxy.plusone.commons.security;
 
+import java.math.BigInteger;
 import java.nio.charset.StandardCharsets;
-import java.security.InvalidKeyException;
+import java.security.GeneralSecurityException;
 import java.security.KeyPair;
 import java.security.KeyPairGenerator;
 import java.security.NoSuchAlgorithmException;
 import java.security.PrivateKey;
 import java.security.PublicKey;
 
-import javax.crypto.BadPaddingException;
 import javax.crypto.Cipher;
-import javax.crypto.IllegalBlockSizeException;
-import javax.crypto.NoSuchPaddingException;
 
 import com.google.common.annotations.Beta;
 
@@ -26,33 +24,20 @@ public class RSA {
 
     private final PublicKey publicKey;
     private final PrivateKey privateKey;
-    private final Cipher encryptModeCipher;
-    private final Cipher decryptModeCipher;
 
-    private RSA(final PublicKey publicKey, final PrivateKey privateKey)
+    private RSA(final PublicKey publicKey, final PrivateKey privateKey) {
-            throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException {
         this.publicKey = publicKey;
         this.privateKey = privateKey;
-        this.encryptModeCipher = Cipher.getInstance(TRANSFORMATION);
-        encryptModeCipher.init(Cipher.ENCRYPT_MODE, publicKey);
-        this.decryptModeCipher = Cipher.getInstance(TRANSFORMATION);
-        decryptModeCipher.init(Cipher.DECRYPT_MODE, privateKey);
     }
 
     public static RSA of(final PublicKey publicKey, final PrivateKey privateKey) {
-        try {
+        return new RSA(publicKey, privateKey);
-            return new RSA(publicKey, privateKey);
+
-        } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException e) {
-            throw new SecurityException(e);
-        }
     }
 
     public static RSA of(final KeyPair keyPair) {
-        try {
+        return new RSA(keyPair.getPublic(), keyPair.getPrivate());
-            return new RSA(keyPair.getPublic(), keyPair.getPrivate());
+
-        } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException e) {
-            throw new SecurityException(e);
-        }
     }
 
     public static RSA withKeySize(int keySize) {
@@ -61,7 +46,7 @@ public class RSA {
             keyPairGenerator.initialize(keySize);
             final KeyPair keyPair = keyPairGenerator.generateKeyPair();
             return new RSA(keyPair.getPublic(), keyPair.getPrivate());
-        } catch (NoSuchAlgorithmException | NoSuchPaddingException | InvalidKeyException e) {
+        } catch (NoSuchAlgorithmException e) {
             throw new SecurityException(e);
         }
     }
@@ -78,27 +63,31 @@ public class RSA {
         return publicKey;
     }
 
-    public byte[] encrypt(byte[] input) throws IllegalBlockSizeException, BadPaddingException {
+    public byte[] encrypt(byte[] input) throws GeneralSecurityException {
+        Cipher encryptModeCipher = Cipher.getInstance(TRANSFORMATION);
+        encryptModeCipher.init(Cipher.ENCRYPT_MODE, publicKey);
         return encryptModeCipher.doFinal(input);
     }
 
-    public byte[] encrypt(String input) throws IllegalBlockSizeException, BadPaddingException {
+    public byte[] encrypt(String input) throws GeneralSecurityException {
         return encrypt(input.getBytes(StandardCharsets.UTF_8));
     }
 
-    public String encryptToString(String input) throws IllegalBlockSizeException, BadPaddingException {
+    public String encryptToString(String input) throws GeneralSecurityException {
-        return new String(encrypt(input));
+        return new BigInteger(1, encrypt(input)).toString(16);
     }
 
-    public byte[] decrypt(byte[] input) throws IllegalBlockSizeException, BadPaddingException {
+    public byte[] decrypt(byte[] input) throws GeneralSecurityException {
+        Cipher decryptModeCipher = Cipher.getInstance(TRANSFORMATION);
+        decryptModeCipher.init(Cipher.DECRYPT_MODE, privateKey);
         return decryptModeCipher.doFinal(input);
     }
 
-    public byte[] decrypt(String input) throws IllegalBlockSizeException, BadPaddingException {
+    public byte[] decrypt(String input) throws GeneralSecurityException {
-        return decryptModeCipher.doFinal(input.getBytes(StandardCharsets.UTF_8));
+        return decrypt(new BigInteger(input, 16).toByteArray());
     }
 
-    public String decryptToString(String input) throws IllegalBlockSizeException, BadPaddingException {
+    public String decryptToString(String input) throws GeneralSecurityException {
         return new String(decrypt(input));
     }
 }