demonstrate simple annotation support

taowen · taowen · commit 11198ae5269c · 2016-12-12T10:01:31.000+08:00
diff --git a/pom.xml b/pom.xml
@@ -7,7 +7,7 @@
     <version>0.9.1</version>
     <artifactId>jsoniter</artifactId>
     <name>json iterator</name>
-    <description>json iterator is fast and easy to use json parser</description>
+    <description>jsoniter (json-iterator) is fast and flexible JSON parser available in Java and Go</description>
     <url>http://jsoniter.com</url>
     <packaging>jar</packaging>
 
diff --git a/src/main/java/com/jsoniter/Codegen.java b/src/main/java/com/jsoniter/Codegen.java
@@ -248,7 +248,12 @@ private static void addFieldDispatch(StringBuilder lines, int len, int i, Map<By
     private static void genField(StringBuilder lines, Field field, String cacheKey) {
         String fieldTypeName = field.getType().getCanonicalName();
         String fieldCacheKey = field.getName() + "@" + cacheKey;
-        if (cache.containsKey(fieldCacheKey)) {
+        Decoder decoder = cache.get(fieldCacheKey);
+        boolean useCustomizedDecoder = decoder != null;
+        if (useCustomizedDecoder && decoder instanceof FieldDecoder) {
+            useCustomizedDecoder = ((FieldDecoder) decoder).useDefaultDecoder();
+        }
+        if (useCustomizedDecoder) {
             append(lines, String.format("obj.%s = (%s)iter.read(\"%s\", %s.class);",
                     field.getName(), fieldTypeName, fieldCacheKey, fieldTypeName));
             return;
diff --git a/src/main/java/com/jsoniter/FieldDecoder.java b/src/main/java/com/jsoniter/FieldDecoder.java
@@ -6,5 +6,11 @@ public interface FieldDecoder extends Decoder {
      *
      * @return null, if field is the field name
      */
-    public String[] getAlternativeFieldNames();
+    String[] getAlternativeFieldNames();
+
+    /**
+     * do not override decode
+     * @return true, for default decoder
+     */
+    boolean useDefaultDecoder();
 }
diff --git a/src/main/java/com/jsoniter/annotation/jsoniter/JsonProperty.java b/src/main/java/com/jsoniter/annotation/jsoniter/JsonProperty.java
@@ -0,0 +1,13 @@
+package com.jsoniter.annotation.jsoniter;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target({ElementType.ANNOTATION_TYPE, ElementType.FIELD, ElementType.METHOD, ElementType.PARAMETER})
+@Retention(RetentionPolicy.RUNTIME)
+public @interface JsonProperty {
+    String USE_DEFAULT_NAME = "";
+    String value() default USE_DEFAULT_NAME;
+}
diff --git a/src/main/java/com/jsoniter/annotation/jsoniter/JsoniterAnnotationSupport.java b/src/main/java/com/jsoniter/annotation/jsoniter/JsoniterAnnotationSupport.java
@@ -0,0 +1,45 @@
+package com.jsoniter.annotation.jsoniter;
+
+import com.jsoniter.*;
+
+import java.io.IOException;
+import java.lang.reflect.Field;
+import java.lang.reflect.Type;
+
+public class JsoniterAnnotationSupport implements FieldDecoderFactory {
+
+    public static void enable() {
+        Jsoniter.registerFieldDecoderFactory(new JsoniterAnnotationSupport());
+    }
+
+    @Override
+    public Decoder createDecoder(final Field field) {
+        JsonProperty annotation = field.getAnnotation(JsonProperty.class);
+        if (annotation == null) {
+            return null;
+        }
+        String alternativeField = annotation.value();
+        if (alternativeField.equals(JsonProperty.USE_DEFAULT_NAME)) {
+            alternativeField = field.getName();
+        }
+        final String[] alternativeFields = new String[]{alternativeField};
+        final String fieldCacheKey = TypeLiteral.generateCacheKey(field.getGenericType());
+        final Class<?> fieldType = field.getType();
+        return new FieldDecoder() {
+            @Override
+            public String[] getAlternativeFieldNames() {
+                return alternativeFields;
+            }
+
+            @Override
+            public boolean useDefaultDecoder() {
+                return false;
+            }
+
+            @Override
+            public Object decode(Type type, Jsoniter iter) throws IOException {
+                return iter.read(fieldCacheKey, fieldType);
+            }
+        };
+    }
+}
diff --git a/src/test/java/com/jsoniter/AnnotatedObject.java b/src/test/java/com/jsoniter/AnnotatedObject.java
@@ -0,0 +1,11 @@
+package com.jsoniter;
+
+import com.jsoniter.annotation.jsoniter.JsonProperty;
+
+public class AnnotatedObject {
+    @JsonProperty("field-1")
+    public int field1;
+
+    @JsonProperty("field-2")
+    public int field2;
+}
diff --git a/src/test/java/com/jsoniter/TestAnnotation.java b/src/test/java/com/jsoniter/TestAnnotation.java
@@ -0,0 +1,15 @@
+package com.jsoniter;
+
+import com.jsoniter.annotation.jsoniter.JsoniterAnnotationSupport;
+import junit.framework.TestCase;
+
+import java.io.IOException;
+
+public class TestAnnotation extends TestCase {
+    public void test() throws IOException {
+        JsoniterAnnotationSupport.enable();
+        Jsoniter iter = Jsoniter.parse("{'field-1': 100}".replace('\'', '"'));
+        AnnotatedObject obj = iter.read(AnnotatedObject.class);
+        assertEquals(100, obj.field1);
+    }
+}
diff --git a/src/test/java/com/jsoniter/TestCustomize.java b/src/test/java/com/jsoniter/TestCustomize.java
@@ -66,6 +66,11 @@ public String[] getAlternativeFieldNames() {
                             return new String[]{"field_1", "Field1"};
                         }
 
+                        @Override
+                        public boolean useDefaultDecoder() {
+                            return false;
+                        }
+
                         @Override
                         public Object decode(Type type, Jsoniter iter) throws IOException {
                             return Integer.toString(iter.readInt());

Original file line number	Diff line number	Diff line change
`@@ -6,5 +6,11 @@ public interface FieldDecoder extends Decoder {`
`6`	`6`	`*`
`7`	`7`	`* @return null, if field is the field name`
`8`	`8`	`*/`
`9`		`- public String[] getAlternativeFieldNames();`
	`9`	`+ String[] getAlternativeFieldNames();`
	`10`	`+`
	`11`	`+ /**`
	`12`	`+ * do not override decode`
	`13`	`+ * @return true, for default decoder`
	`14`	`+ */`
	`15`	`+ boolean useDefaultDecoder();`
`10`	`16`	`}`