微信小程序獲取用戶解密的Session_key 然后對 encryptedData進行解密 偶爾報錯 時間長了之后會報內存溢出：

1. java.lang.OutOfMemoryError: GC overhead limit exceeded
2.  
3. at javax.crypto.JarVerifier.verifySingleJar(JarVerifier.java:426)
4. at javax.crypto.JarVerifier.verifyJars(JarVerifier.java:322)
5. at javax.crypto.JarVerifier.verify(JarVerifier.java:250)
6. at javax.crypto.JceSecurity.verifyProviderJar(JceSecurity.java:160)
7. at javax.crypto.JceSecurity.getVerificationResult(JceSecurity.java:186)
8. at javax.crypto.Cipher.getInstance(Cipher.java:653)

看代碼是java解密的時候報錯了，

然后將老代碼

1.  
2. public byte[] aesCbcDecrypt(byte[] content, byte[] keyBytes, byte[] iv) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
3. //密鑰
4. SecretKey k = new SecretKeySpec(keyBytes, "AES");
5. Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
6.  
7. Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding",
8. new BouncyCastleProvider()
9. );
10.  
11. cipher.init(Cipher.DECRYPT_MODE, k, new IvParameterSpec(iv));
12. //執行操作
13. return cipher.doFinal(content);
14. }

改成如下方式

1. private static Provider provider = new BouncyCastleProvider();
2.  
3. public byte[] aesCbcDecrypt(byte[] content, byte[] keyBytes, byte[] iv) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidAlgorithmParameterException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
4. //密鑰
5. SecretKey k = new SecretKeySpec(keyBytes, "AES");
6. Security.addProvider(new org.bouncycastle.jce.provider.BouncyCastleProvider());
7.  
8. Cipher cipher = Cipher.getInstance("AES/CBC/PKCS7Padding", provider);
9.  
10. cipher.init(Cipher.DECRYPT_MODE, k, new IvParameterSpec(iv));
11. //執行操作
12. return cipher.doFinal(content);
13. }

用Jmeter 100并發壓測 可以檢測到老代碼內存在上升然后短時間不會釋放，新代碼上升然后穩定（和知乎文章鏈接中的結果一致），而且新代碼運行速度也更快（不用每次都new了）。

老代碼cpu：