enh(driver): add spring + mybatis type:byte[] example (#20050)

* enh(driver): add spring + mybatis type:byte[] example

* doc: add init description

* docs: add byte[] description

examples/JDBC/springbootdemo/readme.md

@@ -1,6 +1,13 @@
 ## TDengine SpringBoot + Mybatis Demo
 
 ## 需要提前创建 test 数据库
+
+```
+$ taos -s 'create database if not exists test'
+
+$ curl http://localhost:8080/weather/init
+```
+
 ### 配置 application.properties
 ```properties
 # datasource config

examples/JDBC/springbootdemo/src/main/java/com/taosdata/example/springbootdemo/dao/WeatherMapper.xml

@@ -7,6 +7,7 @@
         <id column="ts" jdbcType="TIMESTAMP" property="ts"/>
         <result column="temperature" jdbcType="FLOAT" property="temperature"/>
         <result column="humidity" jdbcType="FLOAT" property="humidity"/>
+        <result column="bytes" jdbcType="BINARY" property="bytes" />
     </resultMap>
 
     <select id="lastOne" resultType="java.util.Map">
@@ -36,6 +37,11 @@
             binary
         (
             64
+        ),
+            bytes
+            binary
+        (
+            64
         )) tags
         (
             location nchar
@@ -63,8 +69,8 @@
     </select>
 
     <insert id="insert" parameterType="com.taosdata.example.springbootdemo.domain.Weather">
-        insert into test.t#{groupId} (ts, temperature, humidity, note)
+        insert into test.t#{groupId} (ts, temperature, humidity, note, bytes)
-        values (#{ts}, ${temperature}, ${humidity}, #{note})
+        values (#{ts}, ${temperature}, ${humidity}, #{note}, #{bytes})
     </insert>
 
     <select id="getSubTables" resultType="String">

examples/JDBC/springbootdemo/src/main/java/com/taosdata/example/springbootdemo/domain/Weather.java

@@ -2,6 +2,7 @@ package com.taosdata.example.springbootdemo.domain;
 
 import com.fasterxml.jackson.annotation.JsonFormat;
 
+import java.nio.charset.StandardCharsets;
 import java.sql.Timestamp;
 
 public class Weather {
@@ -12,6 +13,9 @@ public class Weather {
     private Float humidity;
     private String location;
     private String note;
+    // In rest mode, the byte[] type is not recommended.
+    // UTF-8 is used to encode the byte arrays, that result may affect the SQL correctness
+    private byte[] bytes;
     private int groupId;
 
     public Weather() {
@@ -70,4 +74,30 @@ public class Weather {
     public void setNote(String note) {
         this.note = note;
     }
+
+    public byte[] getBytes() {
+        return bytes;
+    }
+
+    public void setBytes(byte[] bytes) {
+        this.bytes = bytes;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder sb = new StringBuilder("Weather{");
+        sb.append("ts=").append(ts);
+        sb.append(", temperature=").append(temperature);
+        sb.append(", humidity=").append(humidity);
+        sb.append(", location='").append(location).append('\'');
+        sb.append(", note='").append(note).append('\'');
+        sb.append(", bytes -> string=");
+        if (bytes == null) sb.append("null");
+        else {
+            sb.append(new String(bytes, StandardCharsets.UTF_8));
+        }
+        sb.append(", groupId=").append(groupId);
+        sb.append('}');
+        return sb.toString();
+    }
 }

examples/JDBC/springbootdemo/src/main/java/com/taosdata/example/springbootdemo/service/WeatherService.java

@@ -5,6 +5,7 @@ import com.taosdata.example.springbootdemo.domain.Weather;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Service;
 
+import java.nio.charset.StandardCharsets;
 import java.sql.Timestamp;
 import java.util.List;
 import java.util.Map;
@@ -30,6 +31,7 @@ public class WeatherService {
             weather.setLocation(locations[random.nextInt(locations.length)]);
             weather.setGroupId(i % locations.length);
             weather.setNote("note-" + i);
+            weather.setBytes(locations[random.nextInt(locations.length)].getBytes(StandardCharsets.UTF_8));
             weatherMapper.createTable(weather);
             count += weatherMapper.insert(weather);
         }