Overriding query parameter name (#1184)

* Add possibility to override request parameter name in objects by @param

Fixes #1183

core/src/main/java/feign/Param.java

@@ -1,5 +1,5 @@
 /**
- * Copyright 2012-2019 The Feign Authors
+ * Copyright 2012-2020 The Feign Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -14,15 +14,15 @@
 package feign;
 
 import java.lang.annotation.Retention;
-import static java.lang.annotation.ElementType.PARAMETER;
+import static java.lang.annotation.ElementType.*;
 import static java.lang.annotation.RetentionPolicy.RUNTIME;
 
 /**
- * A named template parameter applied to {@link Headers}, {@linkplain RequestLine} or
- * {@linkplain Body}
+ * A named template parameter applied to {@link Headers}, {@linkplain RequestLine},
+ * {@linkplain Body}, POJO fields or beans properties when it expanding
  */
 @Retention(RUNTIME)
-@java.lang.annotation.Target(PARAMETER)
+@java.lang.annotation.Target({PARAMETER, FIELD, METHOD})
 public @interface Param {
 
   /**

core/src/main/java/feign/querymap/BeanQueryMapEncoder.java

@@ -1,5 +1,5 @@
 /**
- * Copyright 2012-2019 The Feign Authors
+ * Copyright 2012-2020 The Feign Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -13,12 +13,14 @@
  */
 package feign.querymap;
 
+import feign.Param;
 import feign.QueryMapEncoder;
 import feign.codec.EncodeException;
 import java.beans.IntrospectionException;
 import java.beans.Introspector;
 import java.beans.PropertyDescriptor;
 import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
 import java.util.*;
 
 /**
@@ -40,9 +42,12 @@ public Map<String, Object> encode(Object object) throws EncodeException {
       ObjectParamMetadata metadata = getMetadata(object.getClass());
       Map<String, Object> propertyNameToValue = new HashMap<String, Object>();
       for (PropertyDescriptor pd : metadata.objectProperties) {
-        Object value = pd.getReadMethod().invoke(object);
+        Method method = pd.getReadMethod();
+        Object value = method.invoke(object);
         if (value != null && value != object) {
-          propertyNameToValue.put(pd.getName(), value);
+          Param alias = method.getAnnotation(Param.class);
+          String name = alias != null ? alias.value() : pd.getName();
+          propertyNameToValue.put(name, value);
         }
       }
       return propertyNameToValue;

core/src/main/java/feign/querymap/FieldQueryMapEncoder.java

@@ -1,5 +1,5 @@
 /**
- * Copyright 2012-2019 The Feign Authors
+ * Copyright 2012-2020 The Feign Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -13,6 +13,7 @@
  */
 package feign.querymap;
 
+import feign.Param;
 import feign.QueryMapEncoder;
 import feign.codec.EncodeException;
 import java.lang.reflect.Field;
@@ -40,7 +41,9 @@ public Map<String, Object> encode(Object object) throws EncodeException {
       for (Field field : metadata.objectFields) {
         Object value = field.get(object);
         if (value != null && value != object) {
-          fieldNameToValue.put(field.getName(), value);
+          Param alias = field.getAnnotation(Param.class);
+          String name = alias != null ? alias.value() : field.getName();
+          fieldNameToValue.put(name, value);
         }
       }
       return fieldNameToValue;

core/src/test/java/feign/querymap/BeanQueryMapEncoderTest.java

@@ -1,5 +1,5 @@
 /**
- * Copyright 2012-2019 The Feign Authors
+ * Copyright 2012-2020 The Feign Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -13,11 +13,13 @@
  */
 package feign.querymap;
 
+import feign.Param;
 import feign.QueryMapEncoder;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
@@ -70,6 +72,38 @@ public void testDefaultEncoder_haveSuperClass() {
     assertEquals("Unexpected encoded query map", expected, encodedMap);
   }
 
+  @Test
+  public void testDefaultEncoder_withOverriddenParamName() {
+    HashSet<Object> expectedNames = new HashSet<>();
+    expectedNames.add("fooAlias");
+    expectedNames.add("bar");
+    final NormalObjectWithOverriddenParamName normalObject =
+        new NormalObjectWithOverriddenParamName("fooz", "barz");
+
+    final Map<String, Object> encodedMap = encoder.encode(normalObject);
+
+    assertEquals("@Param ignored", expectedNames, encodedMap.keySet());
+  }
+
+  class NormalObjectWithOverriddenParamName {
+
+    private NormalObjectWithOverriddenParamName(String foo, String bar) {
+      this.foo = foo;
+      this.bar = bar;
+    }
+
+    private String foo;
+    private String bar;
+
+    @Param("fooAlias")
+    public String getFoo() {
+      return foo;
+    }
+
+    public String getBar() {
+      return bar;
+    }
+  }
 
   class NormalObject {
 

core/src/test/java/feign/querymap/FieldQueryMapEncoderTest.java

@@ -1,5 +1,5 @@
 /**
- * Copyright 2012-2019 The Feign Authors
+ * Copyright 2012-2020 The Feign Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -13,14 +13,15 @@
  */
 package feign.querymap;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
+import feign.Param;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.Map;
 import feign.QueryMapEncoder;
+import static org.junit.Assert.*;
 
 /**
  * Test for {@link FieldQueryMapEncoder}
@@ -53,6 +54,19 @@ public void testDefaultEncoder_normalClassWithOutValues() {
     assertTrue("Non-empty map generated from null getter: " + encodedMap, encodedMap.isEmpty());
   }
 
+  @Test
+  public void testDefaultEncoder_withOverriddenParamName() {
+    HashSet<Object> expectedNames = new HashSet<>();
+    expectedNames.add("fooAlias");
+    expectedNames.add("bar");
+    final NormalObjectWithOverriddenParamName normalObject =
+        new NormalObjectWithOverriddenParamName("fooz", "barz");
+
+    final Map<String, Object> encodedMap = encoder.encode(normalObject);
+
+    assertEquals("@Param ignored", expectedNames, encodedMap.keySet());
+  }
+
   class NormalObject {
 
     private NormalObject(String foo, String bar) {
@@ -64,4 +78,16 @@ private NormalObject(String foo, String bar) {
     private final String bar;
   }
 
+  class NormalObjectWithOverriddenParamName {
+
+    private NormalObjectWithOverriddenParamName(String foo, String bar) {
+      this.foo = foo;
+      this.bar = bar;
+    }
+
+    @Param("fooAlias")
+    private final String foo;
+    private final String bar;
+  }
+
 }