Support java records as measurement classes (#983)

Author: eranl

MANUAL.md

@@ -323,7 +323,7 @@ public class Cpu {
 }
 ```
 
-2. Add @Measurement,@TimeColumn and @Column annotations (column names default to field names unless otherwise specified):
+2. Add @Measurement, @TimeColumn and @Column annotations (column names default to field names unless otherwise specified):
 
 ```Java
 @Measurement(name = "cpu")
@@ -364,6 +364,24 @@ public class Cpu {
 }
 ```
 
+Or (if you're on JDK14+ and/or [Android SDK34+](https://android-developers.googleblog.com/2023/06/records-in-android-studio-flamingo.html)):
+
+```Java
+@Measurement(name = "cpu", allFields = true)
+public record Cpu(
+    @TimeColumn
+    Instant time,
+    @Column(name = "host", tag = true)
+    String hostname,
+    @Column(tag = true)
+    String region,
+    Double idle,
+    Boolean happydevop,
+    @Column(name = "uptimesecs")
+    Long uptimeSecs
+) {}
+```
+
 3. Call _InfluxDBResultMapper.toPOJO(...)_ to map the QueryResult to your POJO:
 
 ```java

pom.xml

@@ -84,6 +84,10 @@
           <configuration>
             <source>1.8</source>
             <target>1.8</target>
+            <compilerArgs>
+              <!-- Needed for Android desugared record tests -->
+              <arg>-parameters</arg>
+            </compilerArgs>
           </configuration>
         </plugin>
         <plugin>
@@ -405,5 +409,50 @@
         </plugins>
       </build>
     </profile>
+    <profile>
+      <!-- A different setup for JDK 17 -->
+      <id>java17</id>
+      <activation>
+        <jdk>17</jdk>
+      </activation>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.codehaus.mojo</groupId>
+            <artifactId>build-helper-maven-plugin</artifactId>
+            <executions>
+              <execution>
+                <id>add-test-source</id>
+                <phase>generate-test-sources</phase>
+                <goals>
+                  <goal>add-test-source</goal>
+                </goals>
+                <configuration>
+                  <sources>
+                    <source>src/test-jdk17/java</source>
+                  </sources>
+                </configuration>
+              </execution>
+            </executions>
+          </plugin>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-compiler-plugin</artifactId>
+            <inherited>true</inherited>
+            <configuration>
+              <!-- Enable Java 17 for all sources so that Intellij picks the right language level -->
+              <source>17</source>
+              <release>17</release>
+              <compilerArgs>
+                <!-- Needed for record tests -->
+                <arg>-parameters</arg>
+                <arg>--add-opens=java.base/java.lang=ALL-UNNAMED</arg>
+                <arg>--add-opens=java.base/java.util=ALL-UNNAMED</arg>
+              </compilerArgs>
+            </configuration>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
   </profiles>
 </project>

src/main/java/org/influxdb/annotation/Exclude.java

@@ -28,6 +28,9 @@
 /**
  * When a POJO annotated with {@code @Measurement(allFields = true)} is loaded or saved,
  * this annotation can be used to exclude some of its fields.
+ * <p>
+ * Note: this is not considered when loading record measurements.
+ *
  * @see Measurement#allFields()
  *
  * @author Eran Leshem

src/main/java/org/influxdb/annotation/Measurement.java

@@ -44,6 +44,10 @@
   /**
    * If {@code true}, then all non-static fields of this measurement will be loaded or saved,
    * regardless of any {@code @Column} annotations.
+   * <p>
+   * Note: When loading record measurements, this is always implied to be true,
+   * since the record's canonical constructor is used to populate the record.
+   *
    * @see Exclude
    */
   boolean allFields() default false;