添加反射获取泛型信息

byhieg · byhieg · commit 2fe1a4af8cde · 2017-01-09T23:58:56.000+08:00
diff --git a/src/main/java/cn/byhieg/reflectiontutorial/GenericObject.java b/src/main/java/cn/byhieg/reflectiontutorial/GenericObject.java
@@ -0,0 +1,19 @@
+package cn.byhieg.reflectiontutorial;
+
+import java.util.List;
+
+/**
+ * Created by byhieg on 17/1/9.
+ * Mail to byhieg@gmail.com
+ */
+public class GenericObject {
+    public List<String> lists;
+
+    public List<String> getLists() {
+        return lists;
+    }
+
+    public void setLists(List<String> lists) {
+        this.lists = lists;
+    }
+}
diff --git a/src/main/java/cn/byhieg/reflectiontutorial/MyList.java b/src/main/java/cn/byhieg/reflectiontutorial/MyList.java
@@ -0,0 +1,31 @@
+package cn.byhieg.reflectiontutorial;
+
+import java.lang.reflect.Array;
+import java.util.List;
+
+/**
+ * Created by byhieg on 17/1/9.
+ * Mail to byhieg@gmail.com
+ */
+public class MyList<T> {
+
+    public List<T> lists;
+    public List<String> stringLists ;
+
+
+    public List<String> getStringLists() {
+        return stringLists;
+    }
+
+    public void setStringLists(List<String> stringLists) {
+        this.stringLists = stringLists;
+    }
+
+    public void add(T t){
+        lists.add(t);
+    }
+
+    public T get(int index){
+        return lists.get(index);
+    }
+}
diff --git a/src/test/java/cn/byhieg/reflectiontutorialtest/GenericObjectTest.java b/src/test/java/cn/byhieg/reflectiontutorialtest/GenericObjectTest.java
@@ -0,0 +1,59 @@
+package cn.byhieg.reflectiontutorialtest;
+
+import cn.byhieg.reflectiontutorial.GenericObject;
+import com.sun.org.apache.bcel.internal.generic.IF_ACMPEQ;
+import junit.framework.TestCase;
+
+import java.lang.reflect.Field;
+import java.lang.reflect.Method;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.List;
+
+/**
+ * Created by byhieg on 17/1/9.
+ * Mail to byhieg@gmail.com
+ */
+public class GenericObjectTest extends TestCase {
+
+    public void testGeneric()throws Exception{
+        Class clz = GenericObject.class;
+        Method getMethod = clz.getMethod("getLists");
+        Type genericType = getMethod.getGenericReturnType();
+        if(genericType instanceof ParameterizedType){
+            ParameterizedType parameterizedType = ((ParameterizedType) genericType);
+            Type[] types = parameterizedType.getActualTypeArguments();
+            for (Type type : types){
+                Class actualClz = ((Class) type);
+                System.out.println("参数化类型为 ： " + actualClz);
+            }
+        }
+
+        Method setMethod = clz.getMethod("setLists", List.class);
+        Type[] genericParameterTypes = setMethod.getGenericParameterTypes();
+        for (Type genericParameterType: genericParameterTypes){
+            System.out.println("GenericParameterTypes为 ： " + genericParameterType.getTypeName());
+            if(genericParameterType instanceof ParameterizedType){
+                ParameterizedType parameterizedType = ((ParameterizedType) genericParameterType);
+                System.out.println("ParameterizedType为 :" + parameterizedType.getTypeName());
+                Type types[] = parameterizedType.getActualTypeArguments();
+                for (Type type : types){
+                    System.out.println("参数化类型为 ： " + ((Class) type).getName());
+                }
+            }
+
+        }
+
+        Field field = clz.getField("lists");
+        Type type = field.getGenericType();
+        if (type instanceof ParameterizedType){
+            ParameterizedType parameterizedType = ((ParameterizedType) type);
+            Type [] types = parameterizedType.getActualTypeArguments();
+            for (Type type1 : types) {
+                System.out.println("参数化类型 ： " + ((Class) type1).getTypeName());
+            }
+        }
+
+    }
+
+}
diff --git a/src/test/java/cn/byhieg/reflectiontutorialtest/MyListTest.java b/src/test/java/cn/byhieg/reflectiontutorialtest/MyListTest.java
@@ -0,0 +1,16 @@
+package cn.byhieg.reflectiontutorialtest;
+
+import cn.byhieg.reflectiontutorial.MyList;
+import junit.framework.TestCase;
+
+/**
+ * Created by byhieg on 17/1/9.
+ * Mail to byhieg@gmail.com
+ */
+public class MyListTest extends TestCase {
+
+    public void testGeneric() throws Exception{
+        Class clz = MyList.class;
+        System.out.println(clz.getTypeParameters()[0]);
+    }
+}
