简介

chunjun是一款基于flink的开源数据同步工具，官方文档，其提供了很多flink官方未提供的插件供大家来使用，特别是达梦插件在国产化环境中很方便！

本次介绍的是chunjun中的一款http插件，通过该插件可以实现基于http请求的流处理，但是目前官方提供的http插件在以SQL模式运行的时候是有一些问题的，所以我花了些时间将问题排查修复下，并且添加了一个分页的新功能。下面是具体的过程。

问题

按照官方文档使用http插件运行的时候，会报下面的错误

    java.lang.RuntimeException: request data error,msg is prevResponse value is  exception java.lang.RuntimeException: key data.id on {msg=请求成功, total=0, code=0000, data=[{name=第0臭桑, id=0}, {name=第1臭桑, id=1}], timestamp=2023-02-12 16:39:12} is not a json
	
    at com.dtstack.chunjun.util.MapUtil.getValueByKey(MapUtil.java:161)
	at com.dtstack.chunjun.connector.http.client.ResponseParse.buildResponseByKey(ResponseParse.java:63)
	at com.dtstack.chunjun.connector.http.client.JsonResponseParse.next(JsonResponseParse.java:95)
	at com.dtstack.chunjun.connector.http.client.HttpClient.doExecute(HttpClient.java:272)
	at com.dtstack.chunjun.connector.http.client.HttpClient.execute(HttpClient.java:184)
	at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
	at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180)
	at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:750)

	at com.dtstack.chunjun.connector.http.inputformat.HttpInputFormat.nextRecordInternal(HttpInputFormat.java:118)
	at com.dtstack.chunjun.source.format.BaseRichInputFormat.nextRecord(BaseRichInputFormat.java:198)
	at com.dtstack.chunjun.source.format.BaseRichInputFormat.nextRecord(BaseRichInputFormat.java:68)
	at com.dtstack.chunjun.source.DtInputFormatSourceFunction.run(DtInputFormatSourceFunction.java:133)
	at org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:110)
	at org.apache.flink.streaming.api.operators.StreamSource.run(StreamSource.java:66)
	at org.apache.flink.streaming.runtime.tasks.SourceStreamTask$LegacySourceFunctionThread.run(SourceStreamTask.java:267)

解决方案【修改源码】

修改HttpOptions 添加两个配置

// 第一个是配置是数据主体，一般http请求都是标准的统一返回值，有状态码 状态信息 数据主体，我们需要的数据都在数据主体里面的
public static final ConfigOption<String> DATA_SUBJECT =
            ConfigOptions.key("dataSubject")
                    .stringType()
                    .defaultValue("${data}")
                    .withDescription("response data subject");
// 这个配置是发送http请求的周期，如果设置2的话 就会重复请求两次的 如果是-1则会一直重复请求
    public static final ConfigOption<Long> CYCLES =
            ConfigOptions.key("cycles")
                    .longType()
                    .defaultValue(1L)
                    .withDescription("request cycle");

修改HttpDynamicTableFactory

    @Override
    public Set<ConfigOption<?>> optionalOptions() {
        Set<ConfigOption<?>> options = new HashSet<>();
        options.add(HttpOptions.DECODE);
        options.add(HttpOptions.METHOD);
        options.add(HttpOptions.HEADER);
        options.add(HttpOptions.BODY);
        options.add(HttpOptions.PARAMS);
        options.add(HttpOptions.INTERVALTIME);
        options.add(HttpOptions.COLUMN);
        options.add(HttpOptions.DELAY);
        // 下面这俩是对应了with参数
        options.add(HttpOptions.DATA_SUBJECT);
        options.add(HttpOptions.CYCLES);
        return options;
    }

    private HttpRestConfig getRestapiConf(ReadableConfig config) {
        Gson gson = GsonUtil.setTypeAdapter(new Gson());
        HttpRestConfig httpRestConfig = new HttpRestConfig();
        httpRestConfig.setIntervalTime(config.get(HttpOptions.INTERVALTIME));
        httpRestConfig.setUrl(config.get(HttpOptions.URL));
        httpRestConfig.setDecode(config.get(HttpOptions.DECODE));
        httpRestConfig.setRequestMode(config.get(HttpOptions.METHOD));
        // 将上面配置的参数信息封装到http请求配置里面
        httpRestConfig.setDataSubject(config.get(HttpOptions.DATA_SUBJECT));
        httpRestConfig.setCycles(config.get(HttpOptions.CYCLES));
        httpRestConfig.setParam(
                gson.fromJson(
                        config.get(HttpOptions.PARAMS),
                        new TypeToken<List<MetaParam>>() {}.getType()));
        httpRestConfig.setHeader(
                gson.fromJson(
                        config.get(HttpOptions.HEADER),
                        new TypeToken<List<MetaParam>>() {}.getType()));
        httpRestConfig.setBody(
                gson.fromJson(
                        config.get(HttpOptions.BODY),
                        new TypeToken<List<MetaParam>>() {}.getType()));
        httpRestConfig.setColumn(
                gson.fromJson(
                        config.get(HttpOptions.COLUMN),
                        new TypeToken<List<FieldConf>>() {}.getType()));
        return httpRestConfig;
    }

修改HttpRowConverter

// 修改类的泛型 原来是 String 现在需要修改成Map<String,Object>
public class HttpRowConverter
        extends AbstractRowConverter<Map<String, Object>, RowData, RowData, LogicalType>

    // 上面修改了泛型后 这里重写的方法参数类型也会是map类型，在别的地方调用这个方法的时候，传递的就是map类型数据
    // 但是源码里面用String接收的，这样会导致调用方法的时候就出错，而且单步调试的时候就是进不到这个方法的，只能进入到类上
    // 前面传递过来的就是map类型数据了，源码里面，这个方法里的前两行是将字符串转成map的，那也就是说这两行代码不需要了，删除即可
    @Override
    public RowData toInternal(Map<String, Object> result) throws Exception {
        GenericRowData genericRowData = new GenericRowData(rowType.getFieldCount());
        List<String> columns = rowType.getFieldNames();
        for (int pos = 0; pos < columns.size(); pos++) {
            Object value =
                    MapUtil.getValueByKey(
                            result, columns.get(pos), httpRestConfig.getFieldDelimiter());
            if (value instanceof LinkedTreeMap) {
                value = value.toString();
            }
            genericRowData.setField(pos, toInternalConverters.get(pos).deserialize(value));
        }
        return genericRowData;
    }

经过上面的修改之后，可以在with参数里面指定数据主体和请求周期，直接在localTest类运行即可成功！下面是示例的sql

CREATE TABLE source
(
    id   int,
    name varchar
) WITH (
      'connector' = 'http-x'
      ,'url' = 'http://127.0.0.1:8090/test/test'
      ,'intervalTime' = '3000'
      ,'method' = 'get'
      ,'cycles' = '5',
      ,'dataSubject' = '${data}'
      ,'decode' = 'json'
      ,'paging' = 'true'
      ,'pagingParam' = 'pageNumber'
      ,'params' = '[{"key": "pageNumber","value":1,"type":"int"},{"key": "pageSize","value":100,"type":"int"}]'
      ,'column' = '[
              {
                "name": "id",
                "type": "int"
              },
              {
                "name": "name",
                "type": "String"
              }
            ]'
      );

CREATE TABLE sink
(
    id   int,
    name varchar
) WITH (
      'connector' = 'stream-x'
      );

insert into sink
select *
from source u;

后续

目前在上面的基础上，我又加了分页查询的功能，后面有时间会编辑此博客加上分页的源码修改

最后

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