TypeUtil
Introduction
Utility class encapsulation for java.lang.reflect.Type, the main functions include:
- Getting parameter types and return types (both Type and Class) of a method
- Obtaining generic parameter types (including generic parameters of an object or generic types of collections)
Methods
First, let’s define a class:
public class TestClass {
public List<String> getList(){
return new ArrayList<>();
}
public Integer intTest(Integer integer) {
return 1;
}
}getClass
Gets the original class of the Type.
getParamType
Gets the generic type of a method parameter.
Example:
Method method = ReflectUtil.getMethod(TestClass.class, "intTest", Integer.class);
Type type = TypeUtil.getParamType(method, 0);
// Result: Integer.class
getReturnType
Gets the return type of a method.
Example:
Method method = ReflectUtil.getMethod(TestClass.class, "getList");
Type type = TypeUtil.getReturnType(method);
// Result: java.util.List<java.lang.String>
getTypeArgument
Gets the type argument of a generic type.
Example:
Method method = ReflectUtil.getMethod(TestClass.class, "getList");
Type type = TypeUtil.getReturnType(method);
Type type2 = TypeUtil.getTypeArgument(type);
// Result: String.class