How to use:

1. mvn clean install -U
2. mvn package
3. java --add-opens=java.base/java.nio=ALL-UNNAMED -cp target/java-0.1.jar doris.arrowflight.demo.Main "sql" "fe_ip" "fe_arrow_flight_port" "fe_query_port"

What can this demo do:

This is a java demo for doris arrow flight sql, you can use this to test various connection
methods for  sending queries to the doris arrow flight server, help you understand how to use arrow flight sql
and test performance. You should install maven prior to run this demo.

Performance test

Section 6.2 of https://github.com/apache/doris/issues/25514 is the performance test
results of the doris arrow flight sql using java.

Notes

If the following error occurs:
- `module java.base does not "opens java.nio" to unnamed module`
- `module java.base does not "opens java.nio" to org.apache.arrow.memory.core`
- `java.lang.NoClassDefFoundError: Could not initialize class org.apache.arrow.memory.util.MemoryUtil (Internal; Prepare)`

First, add `--add-opens=java.base/java.nio=ALL-UNNAMED` to `JAVA_OPTS_FOR_JDK_17` in fe/conf/fe.conf. Then add `--add-opens=java.base/java.nio=ALL-UNNAMED` in the Java command. If debugging in IntelliJ IDEA, add `--add-opens=java.base/java.nio=ALL-UNNAMED` in `Build and run` of `Run/Debug Configurations`.

For more details, refer to [JDBC Connector with Arrow Flight SQL] and [Java Usage] in the document https://doris.apache.org/zh-CN/docs/dev/db-connect/arrow-flight-sql-connect