编写自定义加密函数，继承ScalarFunction类，实现eval方法，参数个数类型和返回值根据业务来自定义。

import org.apache.flink.table.functions.ScalarFunction;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.Base64;public class AESUtil extends ScalarFunction {private static String DEFAULT_CIPHER_ALGORITHM = "SHA1PRNG";private static String KEY_ALGORITHM = "AES";private static String key = "AD42F6697B035B75";//必须有这个方法，在这个方法里实现业务逻辑public String eval(String str) {return encrypt(str);}/*** 加密** @param key* @param messBytes* @return*/private static byte[] encrypt(Key key, byte[] messBytes) throws Exception {if (key != null) {Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);cipher.init(Cipher.ENCRYPT_MODE, key);return cipher.doFinal(messBytes);}return null;}/*** AES（256）解密** @param key* @param cipherBytes* @return*/private static byte[] decrypt(Key key, byte[] cipherBytes) throws Exception {if (key != null) {Cipher cipher = Cipher.getInstance(KEY_ALGORITHM);cipher.init(Cipher.DECRYPT_MODE, key);return cipher.doFinal(cipherBytes);}return null;}/*** 生成加密秘钥** @return* @throws NoSuchAlgorithmException*/private static KeyGenerator getKeyGenerator() {KeyGenerator keygen = null;try {keygen = KeyGenerator.getInstance(KEY_ALGORITHM);SecureRandom secureRandom = SecureRandom.getInstance(DEFAULT_CIPHER_ALGORITHM);secureRandom.setSeed(key.getBytes());keygen.init(128, secureRandom);} catch (NoSuchAlgorithmException e) {}return keygen;}public static String encrypt(String message) {try {KeyGenerator keygen = getKeyGenerator();SecretKey secretKey = new SecretKeySpec(keygen.generateKey().getEncoded(), KEY_ALGORITHM);return Base64.getEncoder().encodeToString(encrypt(secretKey, message.getBytes(StandardCharsets.UTF_8)));} catch (Exception e) {}return null;}public static String decrypt(String ciphertext) {try {KeyGenerator keygen = getKeyGenerator();SecretKey secretKey = new SecretKeySpec(keygen.generateKey().getEncoded(), KEY_ALGORITHM);return new String(decrypt(secretKey, Base64.getDecoder().decode(ciphertext)), StandardCharsets.UTF_8);} catch (Exception e) {}return null;}

FlinkCDC mysql到mysql 业务代码

import org.apache.flink.api.common.RuntimeExecutionMode;
import org.apache.flink.api.common.restartstrategy.RestartStrategies;
import org.apache.flink.streaming.api.CheckpointingMode;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import org.apache.flink.table.api.EnvironmentSettings;
import org.apache.flink.table.api.Table;
import org.apache.flink.table.api.bridge.java.StreamTableEnvironment;
import org.example.util.AESUtil;public class FlinkMysqlToMysql {public static void main(String[] args) {StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();env.setRestartStrategy(RestartStrategies.fixedDelayRestart(3, 5000));env.enableCheckpointing(5000);env.setRuntimeMode(RuntimeExecutionMode.AUTOMATIC);env.getCheckpointConfig().setCheckpointingMode(CheckpointingMode.EXACTLY_ONCE);
// 创建Table环境EnvironmentSettings settings = EnvironmentSettings.newInstance().useBlinkPlanner().inStreamingMode().build();StreamTableEnvironment tEnv = StreamTableEnvironment.create(env, settings);// 注册源表和目标表tEnv.executeSql("create table sourceTable(id bigint,test VARCHAR, PRIMARY KEY (id) NOT ENFORCED ) WITH (\n" +
//源表连接器一定得是mysql-cdc"'connector' = 'mysql-cdc'," +"'hostname' = 'localhost',\n" +" 'port' = '3306',\n" +" 'database-name' = 'testdb',\n" +" 'table-name' = 'flinktest',\n" +" 'username' = 'root',\n" +" 'password' = 'admin'\n" +")");
//这里注册加密函数tEnv.createTemporarySystemFunction("encrypt", new AESUtil());
//sql里面使用自定义函数加密Table result = tEnv.sqlQuery("SELECT id,encrypt(test) FROM sourceTable");tEnv.registerTable("sourceTable", result);//创建skink表tEnv.executeSql("create table targetTable(id bigint,test VARCHAR ,PRIMARY KEY (id) NOT ENFORCED ) WITH (\n" +
//目标表连接器是jdbc"'connector' = 'jdbc'," +"'url' = 'jdbc:mysql://localhost:3306/testdb?serverTimezone=UTC&useUnicode=true&characterEncoding=utf-8&useSSL=false',\n" +" 'table-name' = 'flinktest2',\n" +" 'username' = 'root',\n" +" 'driver' = 'com.mysql.cj.jdbc.Driver',\n" +" 'password' = 'admin'\n" +")");
// 执行CDC过程String query = "INSERT INTO targetTable SELECT * FROM sourceTable";tEnv.executeSql(query).print();}
}

运行结果，加密成功