小编el3*_*323的帖子

我正在尝试构建一个使用lambda表达式的Kafka Streams应用程序.

我的maven构建配置是mvn clean install

当我执行RunAs> Maven构建时,我收到以下错误:

[ERROR] COMPILATION ERROR : 
[INFO] -------------------------------------------------------------
[ERROR] /home/junaid/eMumba/StreamsExample/streams.examples/src/main/java/myapps/Pipe.java:[53,38] lambda expressions are not supported in -source 1.5
  (use -source 8 or higher to enable lambda expressions)
[INFO] 1 error
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.265 s
[INFO] Finished at: 2018-02-24T14:50:04+05:00
[INFO] Final Memory: 11M/150M
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.1:compile (default-compile) on project streams.examples: Compilation failure
[ERROR] /home/junaid/eMumba/StreamsExample/streams.examples/src/main/java/myapps/Pipe.java:[53,38] lambda expressions are not supported in …

我正在按键对流进行分组，并尝试按分组的键来汇总值。我正在遵循streams-developer-guide

我在遇到错误withValueSerde。它说：

The method withValueSerde(Serde<Object>) in the type Materialized<Object,Object,StateStore> is not applicable for the arguments (Serde<Long>)

码：

KStream<String, String> inputStream = builder.stream("input_topic");
KStream<String, Integer> transformedStream = inputStream.map(
        (key, value) ->  KeyValue.pair(getKey(value), getValue(value)));

KGroupedStream<String, Integer> groupedStream = transformedStream.groupByKey();

KTable<String, Long> aggregatedStream = groupedStream.aggregate(() -> 0L,
        (aggKey, newValue, aggValue) -> aggValue + newValue,
        Materialized.as("aggregated-stream-store").withValueSerde(Serdes.Long()));

我在查询中收到sql异常:

[SqlException(0x80131904):'？'附近的语法不正确.关键字"用户"附近的语法不正确.]

我究竟做错了什么？这个例外意味着什么？

protected void Submit_Click(object sender, EventArgs e)
{
    string myConnection = @"Data Source=REDDEVIL;Initial..."

    SqlConnection conn = new SqlConnection(myConnection);

    HttpPostedFile postedFile = FileUpload1.PostedFile;
    string fileName = Path.GetFileName(postedFile.FileName);
    string fileExtension = Path.GetExtension(fileName);

    if (fileExtension.ToLower() == ".jpg" || fileExtension.ToLower() == ".bmp" ||
        fileExtension.ToLower() == ".gif" || fileExtension.ToLower() == ".png")
    {
        Stream stream = postedFile.InputStream;
        BinaryReader binaryReader = new BinaryReader(stream);
        byte[] bytes = binaryReader.ReadBytes((int)stream.Length);

        string query2 = "INSERT INTO Manager (ID,Name,Address,Phone,Cell,Email,DOB,Commission,Comments,Photo,User ID,IsActive) VALUES (?ID,?Name,?Address,?Phone,?Cell,?Email,?DOB,?Commission,?Comments,?Photo,?User_ID,?IsActive)";
        SqlCommand cmd2 = new SqlCommand(query2, conn);
        cmd2.Parameters.AddWithValue("?ID", mgrID.Text); …

我正在使用 Bootstrap.css，并且有一个名为“form-control”的类。我正在使用这个类来设置我的 aspx 控件的样式。问题是它的文本框字体颜色是灰色的，我希望它是黑色的。我对 CSS 一无所知。有没有办法可以将其从灰色更改为黑色？谢谢。

我想提取每个消息中嵌入的时间戳，并将它们作为json有效负载发送到我的数据库中。

我想获得以下三个时间戳。

活动时间： The point in time when an event or data record occurred, i.e. was originally created “by the source”.

处理时间： The point in time when the event or data record happens to be processed by the stream processing application, i.e. when the record is being consumed.

摄取时间： The point in time when an event or data record is stored in a topic partition by a Kafka broker.

这是我的流应用程序代码：

Properties props = new Properties();

props.put(StreamsConfig.APPLICATION_ID_CONFIG, "streams-pipe");
props.put(StreamsConfig.BOOTSTRAP_SERVERS_CONFIG, BROKER_URL + …

我正在尝试使用 JDBC-sink 连接器将 Kafka 与 Postgres Sink 一起使用。

例外：

INFO Unable to connect to database on attempt 1/3. Will retry in 10000 ms. (io.confluent.connect.jdbc.util.CachedConnectionProvider:91)
java.sql.SQLException: No suitable driver found for jdbc:postgresql://localhost:5432/casb
at java.sql.DriverManager.getConnection(DriverManager.java:689)
    at java.sql.DriverManager.getConnection(DriverManager.java:247)
    at io.confluent.connect.jdbc.util.CachedConnectionProvider.newConnection(CachedConnectionProvider.java:85)
    at io.confluent.connect.jdbc.util.CachedConnectionProvider.getValidConnection(CachedConnectionProvider.java:68)
    at io.confluent.connect.jdbc.sink.JdbcDbWriter.write(JdbcDbWriter.java:56)
    at io.confluent.connect.jdbc.sink.JdbcSinkTask.put(JdbcSinkTask.java:69)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.deliverMessages(WorkerSinkTask.java:495)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.poll(WorkerSinkTask.java:288)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.iteration(WorkerSinkTask.java:198)
    at org.apache.kafka.connect.runtime.WorkerSinkTask.execute(WorkerSinkTask.java:166)
    at org.apache.kafka.connect.runtime.WorkerTask.doRun(WorkerTask.java:170)
    at org.apache.kafka.connect.runtime.WorkerTask.run(WorkerTask.java:214)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)

Sink.properties：

name=test-sink
connector.class=io.confluent.connect.jdbc.JdbcSinkConnector
tasks.max=1
topics=fp_test
connection.url=jdbc:postgresql://localhost:5432/casb
connection.user=admin
connection.password=***
auto.create=true

我已经设定 plugin.path=/usr/share/java/kafka-connect-jdbc

在/usr/share/java/kafka-connect-jdbc我有以下文件：

kafka-connect-jdbc-4.0.0.jar …

我正在尝试从 shell 脚本在 postgres 容器内执行命令。这是我到目前为止：

kubectl exec -it <postgres_pod> -n <deployment> -- bash -c "psql -U postgres -d database -c 'select count from table where name='FOO';'"

我收到以下错误：

ERROR: column "foo" does not exist LINE 1: select count from table where name=FOO; ^

查询在容器内运行良好，因此我传递命令的方式一定有问题。我确实尝试了另一个查询：

kubectl exec -it <postgres_pod> -n <deployment> -- bash -c "psql -U postgres -d database -c 'select * from table;'"

这运行良好。所以，我猜这与我传递 where 子句的方式有关where name='FOO'。我怎样才能让它发挥作用。请帮帮我。

更新：

尝试使用以下方法进行转义：

1：双引号

kubectl exec -it <postgres_pod> -n <deployment> -- bash -c …

我想将纪元以来的天数转换为日期。假设我有以下内容Timestamp in days: 17749，那么它应该转换为Monday Aug 06 2018.

我正在尝试使用以下代码：

Date date = new SimpleDateFormat("D").parse(String.valueOf("17749"));
System.out.println(date);

但我正在得到Sun Aug 05 00:00:00 PKT 2018。日期比应有的日期早一天，如何将其转换为 yyyy-mm-dd？

我想从列表中删除每个第3项.例如:

list1 = list(['a','b','c','d','e','f','g','h','i','j'])

删除多个三的索引后,列表将是:

['a','b','d','e','g','h','j']

我怎样才能做到这一点？