Default column name to pojo field name, and add allFields mode to `…

…Measurement` annotation (#972)
influxdata · Dec 2, 2023 · ba9bfeb · ba9bfeb
1 parent d3a7bbc
commit ba9bfeb
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diff --git a/MANUAL.md b/MANUAL.md
@@ -323,21 +323,40 @@ public class Cpu {
 }
 ```
 
-2. Add @Measurement,@TimeColumn and @Column annotations:
+2. Add @Measurement,@TimeColumn and @Column annotations (column names default to field names unless otherwise specified):
 
 ```Java
 @Measurement(name = "cpu")
 public class Cpu {
     @TimeColumn
-    @Column(name = "time")
+    @Column
     private Instant time;
     @Column(name = "host", tag = true)
     private String hostname;
-    @Column(name = "region", tag = true)
+    @Column(tag = true)
+    private String region;
+    @Column
+    private Double idle;
+    @Column
+    private Boolean happydevop;
+    @Column(name = "uptimesecs")
+    private Long uptimeSecs;
+    // getters (and setters if you need)
+}
+```
+
+Alternatively, you can use:
+
+```Java
+@Measurement(name = "cpu", allFields = true)
+public class Cpu {
+    @TimeColumn
+    private Instant time;
+    @Column(name = "host", tag = true)
+    private String hostname;
+    @Column(tag = true)
     private String region;
-    @Column(name = "idle")
     private Double idle;
-    @Column(name = "happydevop")
     private Boolean happydevop;
     @Column(name = "uptimesecs")
     private Long uptimeSecs;

diff --git a/src/main/java/org/influxdb/annotation/Column.java b/src/main/java/org/influxdb/annotation/Column.java
@@ -32,7 +32,10 @@
 @Target(ElementType.FIELD)
 public @interface Column {
 
-  String name();
+  /**
+   * If unset, the annotated field's name will be used as the column name.
+   */
+  String name() default "";
 
   boolean tag() default false;
 }
diff --git a/src/main/java/org/influxdb/annotation/Exclude.java b/src/main/java/org/influxdb/annotation/Exclude.java
@@ -0,0 +1,38 @@
+/*
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2017 azeti Networks AG (<[email protected]>)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of this software and
+ * associated documentation files (the "Software"), to deal in the Software without restriction,
+ * including without limitation the rights to use, copy, modify, merge, publish, distribute,
+ * sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all copies or
+ * substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
+ * NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
+ * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+package org.influxdb.annotation;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * When a POJO annotated with {@code @Measurement(allFields = true)} is loaded or saved,
+ * this annotation can be used to exclude some of its fields.
+ * @see Measurement#allFields()
+ *
+ * @author Eran Leshem
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.FIELD)
+public @interface Exclude {
+}
diff --git a/src/main/java/org/influxdb/annotation/Measurement.java b/src/main/java/org/influxdb/annotation/Measurement.java
@@ -40,4 +40,11 @@
   String retentionPolicy() default "autogen";
 
   TimeUnit timeUnit() default TimeUnit.MILLISECONDS;
+
+  /**
+   * If {@code true}, then all non-static fields of this measurement will be loaded or saved,
+   * regardless of any {@code @Column} annotations.
+   * @see Exclude
+   */
+  boolean allFields() default false;
 }
diff --git a/src/main/java/org/influxdb/dto/Point.java b/src/main/java/org/influxdb/dto/Point.java
@@ -1,7 +1,15 @@
 package org.influxdb.dto;
 
+import org.influxdb.BuilderException;
+import org.influxdb.annotation.Column;
+import org.influxdb.annotation.Exclude;
+import org.influxdb.annotation.Measurement;
+import org.influxdb.annotation.TimeColumn;
+import org.influxdb.impl.Preconditions;
+
 import java.lang.annotation.Annotation;
 import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
 import java.math.BigDecimal;
 import java.math.BigInteger;
 import java.math.RoundingMode;
@@ -11,14 +19,9 @@
 import java.util.Map;
 import java.util.Map.Entry;
 import java.util.Objects;
-import java.util.TreeMap;
 import java.util.Optional;
+import java.util.TreeMap;
 import java.util.concurrent.TimeUnit;
-import org.influxdb.BuilderException;
-import org.influxdb.annotation.Column;
-import org.influxdb.annotation.Measurement;
-import org.influxdb.annotation.TimeColumn;
-import org.influxdb.impl.Preconditions;
 
 /**
  * Representation of a InfluxDB database Point.
@@ -276,23 +279,34 @@ public boolean hasFields() {
      */
     public Builder addFieldsFromPOJO(final Object pojo) {
 
-      Class<? extends Object> clazz = pojo.getClass();
+      Class<?> clazz = pojo.getClass();
+      Measurement measurement = clazz.getAnnotation(Measurement.class);
+      boolean allFields = measurement != null && measurement.allFields();
+
       while (clazz != null) {
 
         for (Field field : clazz.getDeclaredFields()) {
 
           Column column = field.getAnnotation(Column.class);
 
-          if (column == null) {
+          if (column == null && !(allFields
+                  && !field.isAnnotationPresent(Exclude.class) && !Modifier.isStatic(field.getModifiers()))) {
             continue;
           }
 
           field.setAccessible(true);
-          String fieldName = column.name();
-          addFieldByAttribute(pojo, field, column, fieldName);
+
+          String fieldName;
+          if (column != null && !column.name().isEmpty()) {
+            fieldName = column.name();
+          } else {
+            fieldName = field.getName();
+          }
+
+          addFieldByAttribute(pojo, field, column != null && column.tag(), fieldName);
         }
-      clazz = clazz.getSuperclass();
-    }
+        clazz = clazz.getSuperclass();
+      }
 
       if (this.fields.isEmpty()) {
         throw new BuilderException("Class " + pojo.getClass().getName()
@@ -302,8 +316,8 @@ public Builder addFieldsFromPOJO(final Object pojo) {
       return this;
     }
 
-    private void addFieldByAttribute(final Object pojo, final Field field, final Column column,
-        final String fieldName) {
+    private void addFieldByAttribute(final Object pojo, final Field field, final boolean tag,
+                                     final String fieldName) {
       try {
         Object fieldValue = field.get(pojo);
 
@@ -325,7 +339,7 @@ private void addFieldByAttribute(final Object pojo, final Field field, final Col
           return;
         }
 
-        if (column.tag()) {
+        if (tag) {
           if (fieldValue != null) {
             this.tags.put(fieldName, (String) fieldValue);
           }

diff --git a/src/main/java/org/influxdb/impl/InfluxDBResultMapper.java b/src/main/java/org/influxdb/impl/InfluxDBResultMapper.java
@@ -20,7 +20,14 @@
  */
 package org.influxdb.impl;
 
+import org.influxdb.InfluxDBMapperException;
+import org.influxdb.annotation.Column;
+import org.influxdb.annotation.Exclude;
+import org.influxdb.annotation.Measurement;
+import org.influxdb.dto.QueryResult;
+
 import java.lang.reflect.Field;
+import java.lang.reflect.Modifier;
 import java.time.Instant;
 import java.time.format.DateTimeFormatter;
 import java.time.format.DateTimeFormatterBuilder;
@@ -33,11 +40,6 @@
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.TimeUnit;
 
-import org.influxdb.InfluxDBMapperException;
-import org.influxdb.annotation.Column;
-import org.influxdb.annotation.Measurement;
-import org.influxdb.dto.QueryResult;
-
 /**
  * Main class responsible for mapping a QueryResult to a POJO.
  *
@@ -213,20 +215,34 @@ void cacheMeasurementClass(final Class<?>... classVarAgrs) {
       }
       ConcurrentMap<String, Field> influxColumnAndFieldMap = new ConcurrentHashMap<>();
 
+      Measurement measurement = clazz.getAnnotation(Measurement.class);
+      boolean allFields = measurement != null && measurement.allFields();
+
       Class<?> c = clazz;
       while (c != null) {
         for (Field field : c.getDeclaredFields()) {
           Column colAnnotation = field.getAnnotation(Column.class);
-          if (colAnnotation != null) {
-            influxColumnAndFieldMap.put(colAnnotation.name(), field);
+          if (colAnnotation == null && !(allFields
+                  && !field.isAnnotationPresent(Exclude.class) && !Modifier.isStatic(field.getModifiers()))) {
+            continue;
           }
+
+          influxColumnAndFieldMap.put(getFieldName(field, colAnnotation), field);
         }
         c = c.getSuperclass();
       }
       CLASS_FIELD_CACHE.putIfAbsent(clazz.getName(), influxColumnAndFieldMap);
     }
   }
 
+  private static String getFieldName(final Field field, final Column colAnnotation) {
+    if (colAnnotation != null && !colAnnotation.name().isEmpty()) {
+      return colAnnotation.name();
+    }
+
+    return field.getName();
+  }
+
   String getMeasurementName(final Class<?> clazz) {
     return ((Measurement) clazz.getAnnotation(Measurement.class)).name();
   }
@@ -289,17 +305,11 @@ <T> List<T> parseSeriesAs(final QueryResult.Series series, final Class<T> clazz,
 
   /**
    * InfluxDB client returns any number as Double.
-   * See https://github.com/influxdata/influxdb-java/issues/153#issuecomment-259681987
+   * See <a href="https://github.com/influxdata/influxdb-java/issues/153#issuecomment-259681987">...</a>
    * for more information.
    *
-   * @param object
-   * @param field
-   * @param value
-   * @param precision
-   * @throws IllegalArgumentException
-   * @throws IllegalAccessException
    */
-  <T> void setFieldValue(final T object, final Field field, final Object value, final TimeUnit precision)
+  private static <T> void setFieldValue(final T object, final Field field, final Object value, final TimeUnit precision)
     throws IllegalArgumentException, IllegalAccessException {
     if (value == null) {
       return;
@@ -325,8 +335,8 @@ <T> void setFieldValue(final T object, final Field field, final Object value, fi
     }
   }
 
-  <T> boolean fieldValueModified(final Class<?> fieldType, final Field field, final T object, final Object value,
-                                 final TimeUnit precision)
+  static <T> boolean fieldValueModified(final Class<?> fieldType, final Field field, final T object, final Object value,
+                                        final TimeUnit precision)
     throws IllegalArgumentException, IllegalAccessException {
     if (String.class.isAssignableFrom(fieldType)) {
       field.set(object, String.valueOf(value));
@@ -351,8 +361,9 @@ <T> boolean fieldValueModified(final Class<?> fieldType, final Field field, fina
     return false;
   }
 
-  <T> boolean fieldValueForPrimitivesModified(final Class<?> fieldType, final Field field, final T object,
-    final Object value) throws IllegalArgumentException, IllegalAccessException {
+  static <T> boolean fieldValueForPrimitivesModified(final Class<?> fieldType, final Field field, final T object,
+                                                     final Object value)
+          throws IllegalArgumentException, IllegalAccessException {
     if (double.class.isAssignableFrom(fieldType)) {
       field.setDouble(object, ((Double) value).doubleValue());
       return true;
@@ -372,8 +383,9 @@ <T> boolean fieldValueForPrimitivesModified(final Class<?> fieldType, final Fiel
     return false;
   }
 
-  <T> boolean fieldValueForPrimitiveWrappersModified(final Class<?> fieldType, final Field field, final T object,
-    final Object value) throws IllegalArgumentException, IllegalAccessException {
+  static <T> boolean fieldValueForPrimitiveWrappersModified(final Class<?> fieldType, final Field field, final T object,
+                                                            final Object value)
+          throws IllegalArgumentException, IllegalAccessException {
     if (Double.class.isAssignableFrom(fieldType)) {
       field.set(object, value);
       return true;
@@ -393,7 +405,7 @@ <T> boolean fieldValueForPrimitiveWrappersModified(final Class<?> fieldType, fin
     return false;
   }
 
-  private Long toMillis(final long value, final TimeUnit precision) {
+  private static Long toMillis(final long value, final TimeUnit precision) {
 
     return TimeUnit.MILLISECONDS.convert(value, precision);
   }