public void setSourceKeyId(String sourceKeyId) {
        this.sourceKeyId = sourceKeyId;
    }
<p>
Specifies the KMS key that KMS will use to decrypt the ciphertext before it is re-encrypted.
</p>
<p>
Enter a key ID of the KMS key that was used to encrypt the ciphertext. If you identify a different KMS key, the
<code>ReEncrypt</code> operation throws an <code>IncorrectKeyException</code>.
</p>
<p>
This parameter is required only when the ciphertext was encrypted under an asymmetric KMS key. If you used a
symmetric encryption KMS key, KMS can get the KMS key from metadata that it adds to the symmetric ciphertext
blob. However, it is always recommended as a best practice. This practice ensures that you use the KMS key that
you intend.
</p>
<p>
To specify a KMS key, use its key ID, key ARN, alias name, or alias ARN. When using an alias name, prefix it with
<code>"alias/"</code>. To specify a KMS key in a different Amazon Web Services account, you must use the key ARN
or alias ARN.
</p>
<p>
For example:
</p>
<ul>
<li>
<p>
Key ID: <code>1234abcd-12ab-34cd-56ef-1234567890ab</code>
</p>
</li>
<li>
<p>
Key ARN: <code>arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab</code>
</p>
</li>
<li>
<p>
Alias name: <code>alias/ExampleAlias</code>
</p>
</li>
<li>
<p>
Alias ARN: <code>arn:aws:kms:us-east-2:111122223333:alias/ExampleAlias</code>
</p>
</li>
</ul>
<p>
To get the key ID and key ARN for a KMS key, use <a>ListKeys</a> or <a>DescribeKey</a>. To get the alias name and
alias ARN, use <a>ListAliases</a>.
</p>

@param sourceKeyId
       Specifies the KMS key that KMS will use to decrypt the ciphertext before it is re-encrypted.</p>
       <p>
       Enter a key ID of the KMS key that was used to encrypt the ciphertext. If you identify a different KMS
       key, the <code>ReEncrypt</code> operation throws an <code>IncorrectKeyException</code>.
       </p>
       <p>
       This parameter is required only when the ciphertext was encrypted under an asymmetric KMS key. If you used
       a symmetric encryption KMS key, KMS can get the KMS key from metadata that it adds to the symmetric
       ciphertext blob. However, it is always recommended as a best practice. This practice ensures that you use
       the KMS key that you intend.
       </p>
       <p>
       To specify a KMS key, use its key ID, key ARN, alias name, or alias ARN. When using an alias name, prefix
       it with <code>"alias/"</code>. To specify a KMS key in a different Amazon Web Services account, you must
       use the key ARN or alias ARN.
       </p>
       <p>
       For example:
       </p>
       <ul>
       <li>
       <p>
       Key ID: <code>1234abcd-12ab-34cd-56ef-1234567890ab</code>
       </p>
       </li>
       <li>
       <p>
       Key ARN: <code>arn:aws:kms:us-east-2:111122223333:key/1234abcd-12ab-34cd-56ef-1234567890ab</code>
       </p>
       </li>
       <li>
       <p>
       Alias name: <code>alias/ExampleAlias</code>
       </p>
       </li>
       <li>
       <p>
       Alias ARN: <code>arn:aws:kms:us-east-2:111122223333:alias/ExampleAlias</code>
       </p>
       </li>
       </ul>
       <p>
       To get the key ID and key ARN for a KMS key, use <a>ListKeys</a> or <a>DescribeKey</a>. To get the alias
       name and alias ARN, use <a>ListAliases</a>.
aws-java-sdk-kms/src/main/java/com/amazonaws/services/kms/model/ReEncryptRequest.java