kettle从入门到精通 第四十五课 ETL之 kettle redis
·
1、kettle 9.3/9.4 spoon客户端中默认是没有redis步骤的,首先想到在kettle的插件市场进行下载redis步骤。

2、可能因为网络原因,直接下载失败了。索性放弃redis原有插件步骤,改为自己通过java代码进行实现,(有java基础的可以通过java代码步骤结合自定义jar包实现一切功能)。

3、将jedis-2.10.2.jar(jedis版本最好和jdk1版本匹配) 放到kettle的lib目录下,重启spoon客户端。
步骤【生成记录】生成一笔测试数据,步骤【Java代码-redis-set】往redis里面写数据,步骤【Java代码-redis-get】从redis读取数据,如下图所示。

4、步骤【java代码-redis-set】实现逻辑如下:

代码中import 包时,一定要放到最顶部。下面代码中标红的部分为关键代码,其他为模版代码。
import redis.clients.jedis.Jedis;
public boolean processRow(StepMetaInterface smi, StepDataInterface sdi) throws KettleException {
if (first) {
first = false;
/* TODO: Your code here. (Using info fields)
FieldHelper infoField = get(Fields.Info, "info_field_name");
RowSet infoStream = findInfoRowSet("info_stream_tag");
Object[] infoRow = null;
int infoRowCount = 0;
// Read all rows from info step before calling getRow() method, which returns first row from any
// input rowset. As rowMeta for info and input steps varies getRow() can lead to errors.
while((infoRow = getRowFrom(infoStream)) != null){
// do something with info data
infoRowCount++;
}
*/
}
Object[] r = getRow();
if (r == null) {
setOutputDone();
return false;
}
Jedis jedis = new Jedis("localhost", 6379);
// 设置键值对
jedis.set("name", "Java小金刚");
// 关闭连接
jedis.close();
// It is always safest to call createOutputRow() to ensure that your output row's Object[] is large
// enough to handle any new fields you are creating in this step.
r = createOutputRow(r, data.outputRowMeta.size());
/* TODO: Your code here. (See Sample)
// Get the value from an input field
String foobar = get(Fields.In, "a_fieldname").getString(r);
foobar += "bar";
// Set a value in a new output field
get(Fields.Out, "output_fieldname").setValue(r, foobar);
*/
// Send the row on to the next step.
putRow(data.outputRowMeta, r);
return true;
}
5、步骤【java代码-redis-get】实现逻辑如下:

代码中import 包时,一定要放到最顶部。下面代码中标红的部分为关键代码,其他为模版代码。
import redis.clients.jedis.Jedis;
public boolean processRow(StepMetaInterface smi, StepDataInterface sdi) throws KettleException {
if (first) {
first = false;
/* TODO: Your code here. (Using info fields)
FieldHelper infoField = get(Fields.Info, "info_field_name");
RowSet infoStream = findInfoRowSet("info_stream_tag");
Object[] infoRow = null;
int infoRowCount = 0;
// Read all rows from info step before calling getRow() method, which returns first row from any
// input rowset. As rowMeta for info and input steps varies getRow() can lead to errors.
while((infoRow = getRowFrom(infoStream)) != null){
// do something with info data
infoRowCount++;
}
*/
}
Object[] r = getRow();
if (r == null) {
setOutputDone();
return false;
}
Jedis jedis = new Jedis("localhost", 6379);
// 获取键值对
String name = jedis.get("name");
// 关闭连接
jedis.close();
// It is always safest to call createOutputRow() to ensure that your output row's Object[] is large
// enough to handle any new fields you are creating in this step.
r = createOutputRow(r, data.outputRowMeta.size());
/* TODO: Your code here. (See Sample)
// Get the value from an input field
String foobar = get(Fields.In, "a_fieldname").getString(r);
foobar += "bar";
// Set a value in a new output field
get(Fields.Out, "output_fieldname").setValue(r, foobar);
*/
get(Fields.Out, "name").setValue(r, name);
// Send the row on to the next step.
putRow(data.outputRowMeta, r);
return true;
}

更多推荐


所有评论(0)