Flink批处理之读写Mysql
1、添加Maven坐标
MySQL
mysql-connector-java
5.1.48
org.apache.flink
flink-jdbc_2.12
1.8.0
2、建表
CREATE TABLE `temp` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`name` varchar(255) DEFAULT NULL,
`time` varchar(255) DEFAULT NULL,
`type` bigint(20) DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8
3、 Show Code
package com.fwmagic.flink.batch;
import org.apache.flink.api.common.functions.MapFunction;
import org.apache.flink.api.common.typeinfo.BasicTypeInfo;
import org.apache.flink.api.java.DataSet;
import org.apache.flink.api.java.ExecutionEnvironment;
import org.apache.flink.api.java.io.jdbc.JDBCInputFormat;
import org.apache.flink.api.java.io.jdbc.JDBCOutputFormat;
import org.apache.flink.api.java.operators.DataSource;
import org.apache.flink.api.java.tuple.Tuple3;
import org.apache.flink.api.java.typeutils.RowTypeInfo;
import org.apache.flink.types.Row;
import java.util.concurrent.TimeUnit;
public class BatchDemoOperatorMysql {
public static void main(String[] args) throws Exception {
String driverClass = "com.mysql.jdbc.Driver";
String dbUrl = "jdbc:mysql://localhost:3306/test";
String userNmae = "root";
String passWord = "123456";
String sql = "insert into test.temp (name,time,type) values (?,?,?)";
ExecutionEnvironment env = ExecutionEnvironment.getExecutionEnvironment();
/**
* 文件内容:
* 关羽,2019-10-14 00:00:01,1
* 张飞,2019-10-14 00:00:02,2
* 赵云,2019-10-14 00:00:03,3
*/
String filePath = "/Users/temp/data.csv";
//读csv文件内容,转成Row对象
DataSet outputData = env.readCsvFile(filePath).fieldDelimiter(",").types(String.class, String.class, Long.class).map(new MapFunction, Row>() {
@Override
public Row map(Tuple3 t) throws Exception {
Row row = new Row(3);
row.setField(0, t.f0.getBytes("UTF-8"));
row.setField(1, t.f1.getBytes("UTF-8"));
row.setField(2, t.f2.longValue());
return row;
}
});
//将Row对象写到mysql
outputData.output(JDBCOutputFormat.buildJDBCOutputFormat()
.setDrivername(driverClass)
.setDBUrl(dbUrl)
.setUsername(userNmae)
.setPassword(passWord)
.setQuery(sql)
.finish());
//触发执行
env.execute("insert data to mysql");
System.out.println("mysql写入成功!");
TimeUnit.SECONDS.sleep(6);
//读mysql
DataSource dataSource = env.createInput(JDBCInputFormat.buildJDBCInputFormat()
.setDrivername(driverClass)
.setDBUrl(dbUrl)
.setUsername(userNmae)
.setPassword(passWord)
.setQuery("select * from temp")
.setRowTypeInfo(new RowTypeInfo(BasicTypeInfo.STRING_TYPE_INFO, BasicTypeInfo.STRING_TYPE_INFO, BasicTypeInfo.LONG_TYPE_INFO))
.finish());
//获取数据并打印
dataSource.map(new MapFunction() {
@Override
public String map(Row value) throws Exception {
System.out.println(value);
return value.toString();
}
}).print();
}
}
4、注意事项
- 数据写入mysql的DataSet泛型要求是row,需要转换;
- 数据读取的结果也是row类型,不能直接print,需要转换;
- 数据写入后一定要加上env.execute(),触发任务执行;
- 涉及到中文的,需要转换成UTF-8,不然数据库中会出现乱码。
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