flink怎么读取mysql数据

```java

import org.apache.flink.api.java.io.jdbc.JDBCInputFormat;

import org.apache.flink.api.java.typeutils.RowTypeInfo;

import org.apache.flink.api.java.tuple.Tuple2;

import org.apache.flink.types.Row;

public class ReadMySQLData {

public static void main(String[] args) {

String driverClassName = "com.mysql.jdbc.Driver";

String dbURL = "jdbc:mysql://localhost:3306/your_database";

String query = "SELECT * FROM your_table";

RowTypeInfo rowTypeInfo = new RowTypeInfo(/* define your row types here */);

JDBCInputFormat jdbcInputFormat = JDBCInputFormat.buildJDBCInputFormat()

.setDrivername(driverClassName)

.setDBUrl(dbURL)

.setUsername("your_username")

.setPassword("your_password")

.setQuery(query)

.setRowTypeInfo(rowTypeInfo)

.finish();

DataStream jdbcDataStream = env.createInput(jdbcInputFormat);

jdbcDataStream.print();

env.execute("Read MySQL Data");

}

}

```

请注意，上述代码中的`driverClassName`、`dbURL`、`query`、`username`和`password`需要根据你的实际情况进行修改。同时，还需要定义`RowTypeInfo`来描述从MySQL中读取的数据的类型。