Package org.jooq.tools.reflect

Class Reflect

  • public class Reflect
extends java.lang.Object
    A wrapper for an Object or Class upon which reflective calls can be made.

    An example of using Reflect is 

     // Static import all reflection methods to decrease verbosity
 import static org.joor.Reflect.*;

 // Wrap an Object / Class / class name with the on() method:
 on("java.lang.String")
 // Invoke constructors using the create() method:
 .create("Hello World")
 // Invoke methods using the call() method:
 .call("toString")
 // Retrieve the wrapped object
    Author:
    Lukas Eder, Irek Matysiewicz, Thomas Darimont

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      static <T extends java.lang.reflect.AccessibleObject>
      T      		 accessible​(T accessible)
      Conveniently render an AccessibleObject accessible.
      <P> P as​(java.lang.Class<P> proxyType)
      Create a proxy for the wrapped object allowing to typesafely invoke methods on it using a custom interface.
      <P> P as​(java.lang.Class<P> proxyType, java.lang.Class<?>... additionalInterfaces)
      Create a proxy for the wrapped object allowing to typesafely invoke methods on it using a custom interface.
      Reflect call​(java.lang.String name)
      Call a method by its name.
      Reflect call​(java.lang.String name, java.lang.Object... args)
      Call a method by its name.
      static Reflect compile​(java.lang.String name, java.lang.String content)
      Compile a class at runtime and reflect on it.
      static Reflect compile​(java.lang.String name, java.lang.String content, CompileOptions options)
      Compile a class at runtime and reflect on it.
      Reflect create()
      Call a constructor.
      Reflect create​(java.lang.Object... args)
      Call a constructor.
      boolean equals​(java.lang.Object obj)  
      Reflect field​(java.lang.String name)
      Get a wrapped field.
      java.util.Map<java.lang.String,​Reflect> fields()
      Get a Map containing field names and wrapped values for the fields' values.
      <T> T get()
      Get the wrapped object
      <T> T get​(java.lang.String name)
      Get a field value.
      int hashCode()  
      static <T> T initValue​(java.lang.Class<T> type)
      Get the initialisation or default value for any given type.
      static Reflect on​(java.lang.Class<?> clazz)
      Deprecated.
      [#78] 0.9.11, use onClass(Class) instead.
      static Reflect on​(java.lang.Object object)
      Wrap an object.
      static Reflect on​(java.lang.String name)
      Deprecated.
      [#78] 0.9.11, use onClass(String) instead.
      static Reflect on​(java.lang.String name, java.lang.ClassLoader classLoader)
      Deprecated.
      [#78] 0.9.11, use onClass(String, ClassLoader) instead.
      static Reflect onClass​(java.lang.Class<?> clazz)
      Wrap a class.
      static Reflect onClass​(java.lang.String name)
      Wrap a class name.
      static Reflect onClass​(java.lang.String name, java.lang.ClassLoader classLoader)
      Wrap a class name, loading it via a given class loader.
      Reflect set​(java.lang.String name, java.lang.Object value)
      Set a field value.
      java.lang.String toString()  
      java.lang.Class<?> type()
      Get the type of the wrapped object.
      static java.lang.Class<?> wrapper​(java.lang.Class<?> type)
      Get a wrapper type for a primitive type, or the argument type itself, if it is not a primitive type.

      • Methods inherited from class java.lang.Object

        clone, finalize, getClass, notify, notifyAll, wait, wait, wait

    • Method Detail

      • compile

        public static Reflect compile​(java.lang.String name,
                              java.lang.String content)
                       throws ReflectException
        Compile a class at runtime and reflect on it.

        For example: 

         Supplier<String> supplier = Reflect.compile(
   "org.joor.Test",
   "package org.joor;\n" +
   "class Test implements java.util.function.Supplier<String> {\n" +
   "  public String get() {\n" +
   "    return \"Hello World!\";\n" +
   "  }\n" +
   "}\n").create().get();
        Parameters:
        name - The qualified class name
        content - The source code for the class
        Returns:
        A wrapped Class
        Throws:
        ReflectException - if anything went wrong compiling the class.

      • compile

        public static Reflect compile​(java.lang.String name,
                              java.lang.String content,
                              CompileOptions options)
                       throws ReflectException
        Compile a class at runtime and reflect on it.

        For example: 

         Supplier<String> supplier = Reflect.compile(
   "org.joor.Test",
   "package org.joor;\n" +
   "class Test implements java.util.function.Supplier<String> {\n" +
   "  public String get() {\n" +
   "    return \"Hello World!\";\n" +
   "  }\n" +
   "}\n").create().get();
        Parameters:
        name - The qualified class name
        content - The source code for the class
        options - compiler options
        Returns:
        A wrapped Class
        Throws:
        ReflectException - if anything went wrong compiling the class.

      • on

        @Deprecated
public static Reflect on​(java.lang.String name)
                  throws ReflectException
        Deprecated.
        [#78] 0.9.11, use onClass(String) instead.
        Wrap a class name.

        This is the same as calling on(Class.forName(name))

        Parameters:
        name - A fully qualified class name
        Returns:
        A wrapped class object, to be used for further reflection.
        Throws:
        ReflectException - If any reflection exception occurred.
        See Also:
        onClass(Class)

      • on

        @Deprecated
public static Reflect on​(java.lang.String name,
                         java.lang.ClassLoader classLoader)
                  throws ReflectException
        Deprecated.
        [#78] 0.9.11, use onClass(String, ClassLoader) instead.
        Wrap a class name, loading it via a given class loader.

        This is the same as calling on(Class.forName(name, classLoader))

        Parameters:
        name - A fully qualified class name.
        classLoader - The class loader in whose context the class should be loaded.
        Returns:
        A wrapped class object, to be used for further reflection.
        Throws:
        ReflectException - If any reflection exception occurred.
        See Also:
        onClass(Class)

      • on

        @Deprecated
public static Reflect on​(java.lang.Class<?> clazz)
        Deprecated.
        [#78] 0.9.11, use onClass(Class) instead.
        Wrap a class.

        Use this when you want to access static fields and methods on a Class object, or as a basis for constructing objects of that class using create(Object...)

        Parameters:
        clazz - The class to be wrapped
        Returns:
        A wrapped class object, to be used for further reflection.

      • onClass

        public static Reflect onClass​(java.lang.String name)
                       throws ReflectException
        Wrap a class name.

        This is the same as calling onClass(Class.forName(name))

        Parameters:
        name - A fully qualified class name
        Returns:
        A wrapped class object, to be used for further reflection.
        Throws:
        ReflectException - If any reflection exception occurred.
        See Also:
        onClass(Class)

      • onClass

        public static Reflect onClass​(java.lang.String name,
                              java.lang.ClassLoader classLoader)
                       throws ReflectException
        Wrap a class name, loading it via a given class loader.

        This is the same as calling onClass(Class.forName(name, classLoader))

        Parameters:
        name - A fully qualified class name.
        classLoader - The class loader in whose context the class should be loaded.
        Returns:
        A wrapped class object, to be used for further reflection.
        Throws:
        ReflectException - If any reflection exception occurred.
        See Also:
        onClass(Class)

      • onClass

        public static Reflect onClass​(java.lang.Class<?> clazz)
        Wrap a class.

        Use this when you want to access static fields and methods on a Class object, or as a basis for constructing objects of that class using create(Object...)

        Parameters:
        clazz - The class to be wrapped
        Returns:
        A wrapped class object, to be used for further reflection.

      • on

        public static Reflect on​(java.lang.Object object)
        Wrap an object.

        Use this when you want to access instance fields and methods on any Object

        Parameters:
        object - The object to be wrapped
        Returns:
        A wrapped object, to be used for further reflection.

      • initValue

        public static <T> T initValue​(java.lang.Class<T> type)
        Get the initialisation or default value for any given type.

        This returns:

        • null for reference types (including wrapper types)
        • 0 for numeric primitive types (including char)
        • false for the boolean primitive type.

      • accessible

        public static <T extends java.lang.reflect.AccessibleObject> T accessible​(T accessible)
        Conveniently render an AccessibleObject accessible.

        To prevent SecurityException, this is only done if the argument object and its declaring class are non-public.

        Parameters:
        accessible - The object to render accessible
        Returns:
        The argument object rendered accessible

      • get

        public <T> T get()
        Get the wrapped object
        Type Parameters:
        T - A convenience generic parameter for automatic unsafe casting

      • set

        public Reflect set​(java.lang.String name,
                   java.lang.Object value)
            throws ReflectException
        Set a field value.

        This is roughly equivalent to Field.set(Object, Object). If the wrapped object is a Class, then this will set a value to a static member field. If the wrapped object is any other Object, then this will set a value to an instance member field.

        This method is also capable of setting the value of (static) final fields. This may be convenient in situations where no SecurityManager is expected to prevent this, but do note that (especially static) final fields may already have been inlined by the javac and/or JIT and relevant code deleted from the runtime verison of your program, so setting these fields might not have any effect on your execution.

        For restrictions of usage regarding setting values on final fields check: http://stackoverflow.com/questions/3301635/change-private-static-final-field-using-java-reflection ... and http://pveentjer.blogspot.co.at/2017/01/final-static-boolean-jit.html

        Parameters:
        name - The field name
        value - The new field value
        Returns:
        The same wrapped object, to be used for further reflection.
        Throws:
        ReflectException - If any reflection exception occurred.

      • get

        public <T> T get​(java.lang.String name)
          throws ReflectException
        Get a field value.

        This is roughly equivalent to Field.get(Object). If the wrapped object is a Class, then this will get a value from a static member field. If the wrapped object is any other Object, then this will get a value from an instance member field.

        If you want to "navigate" to a wrapped version of the field, use field(String) instead.

        Parameters:
        name - The field name
        Returns:
        The field value
        Throws:
        ReflectException - If any reflection exception occurred.
        See Also:
        field(String)

      • field

        public Reflect field​(java.lang.String name)
              throws ReflectException
        Get a wrapped field.

        This is roughly equivalent to Field.get(Object). If the wrapped object is a Class, then this will wrap a static member field. If the wrapped object is any other Object, then this wrap an instance member field.

        Parameters:
        name - The field name
        Returns:
        The wrapped field
        Throws:
        ReflectException - If any reflection exception occurred.

      • fields

        public java.util.Map<java.lang.String,​Reflect> fields()
        Get a Map containing field names and wrapped values for the fields' values.

        If the wrapped object is a Class, then this will return static fields. If the wrapped object is any other Object, then this will return instance fields.

        These two calls are equivalent 

         on(object).field("myField");
 on(object).fields().get("myField");
        Returns:
        A map containing field names and wrapped values.

      • call

        public Reflect call​(java.lang.String name)
             throws ReflectException
        Call a method by its name.

        This is a convenience method for calling call(name, new Object[0])

        Parameters:
        name - The method name
        Returns:
        The wrapped method result or the same wrapped object if the method returns void, to be used for further reflection.
        Throws:
        ReflectException - If any reflection exception occurred.
        See Also:
        call(String, Object...)

      • call

        public Reflect call​(java.lang.String name,
                    java.lang.Object... args)
             throws ReflectException
        Call a method by its name.

        This is roughly equivalent to Method.invoke(Object, Object...). If the wrapped object is a Class, then this will invoke a static method. If the wrapped object is any other Object, then this will invoke an instance method.

        Just like Method.invoke(Object, Object...), this will try to wrap primitive types or unwrap primitive type wrappers if applicable. If several methods are applicable, by that rule, the first one encountered is called. i.e. when calling 

         on(...).call("method", 1, 1);
        The first of the following methods will be called: 
         public void method(int param1, Integer param2);
 public void method(Integer param1, int param2);
 public void method(Number param1, Number param2);
 public void method(Number param1, Object param2);
 public void method(int param1, Object param2);

        The best matching method is searched for with the following strategy:

        1. public method with exact signature match in class hierarchy
        2. non-public method with exact signature match on declaring class
        3. public method with similar signature in class hierarchy
        4. non-public method with similar signature on declaring class
        Parameters:
        name - The method name
        args - The method arguments
        Returns:
        The wrapped method result or the same wrapped object if the method returns void, to be used for further reflection.
        Throws:
        ReflectException - If any reflection exception occurred.

      • create

        public Reflect create()
               throws ReflectException
        Call a constructor.

        This is a convenience method for calling create(new Object[0])

        Returns:
        The wrapped new object, to be used for further reflection.
        Throws:
        ReflectException - If any reflection exception occurred.
        See Also:
        create(Object...)

      • create

        public Reflect create​(java.lang.Object... args)
               throws ReflectException
        Call a constructor.

        This is roughly equivalent to Constructor.newInstance(Object...). If the wrapped object is a Class, then this will create a new object of that class. If the wrapped object is any other Object, then this will create a new object of the same type.

        Just like Constructor.newInstance(Object...), this will try to wrap primitive types or unwrap primitive type wrappers if applicable. If several constructors are applicable, by that rule, the first one encountered is called. i.e. when calling 

         on(C.class).create(1, 1);
        The first of the following constructors will be applied: 
         public C(int param1, Integer param2);
 public C(Integer param1, int param2);
 public C(Number param1, Number param2);
 public C(Number param1, Object param2);
 public C(int param1, Object param2);
        Parameters:
        args - The constructor arguments
        Returns:
        The wrapped new object, to be used for further reflection.
        Throws:
        ReflectException - If any reflection exception occurred.

      • as

        public <P> P as​(java.lang.Class<P> proxyType)
        Create a proxy for the wrapped object allowing to typesafely invoke methods on it using a custom interface.
        Parameters:
        proxyType - The interface type that is implemented by the proxy
        Returns:
        A proxy for the wrapped object

      • as

        public <P> P as​(java.lang.Class<P> proxyType,
                java.lang.Class<?>... additionalInterfaces)
        Create a proxy for the wrapped object allowing to typesafely invoke methods on it using a custom interface.
        Parameters:
        proxyType - The interface type that is implemented by the proxy
        additionalInterfaces - Additional interfaces that are implemented by the proxy
        Returns:
        A proxy for the wrapped object

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class java.lang.Object

      • equals

        public boolean equals​(java.lang.Object obj)
        Overrides:
        equals in class java.lang.Object

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • type

        public java.lang.Class<?> type()
        Get the type of the wrapped object.
        See Also:
        Object.getClass()

      • wrapper

        public static java.lang.Class<?> wrapper​(java.lang.Class<?> type)
        Get a wrapper type for a primitive type, or the argument type itself, if it is not a primitive type.