Package org.apache.juneau.objecttools

Class ObjectIntrospector

java.lang.Object

org.apache.juneau.objecttools.ObjectIntrospector

public class ObjectIntrospector
extends Object

POJO method introspector.

This class is used to invoke methods on Objects using arguments in serialized form.

Example:

String string1 = "foobar"; String string2 = ObjectIntrospector .create(string) .invoke(String.class, "substring(int,int)", "[3,6]"); // "bar"

The arguments passed to the identified method are POJOs serialized in JSON format. Arbitrarily complex arguments can be passed in as arguments.

• This is an extremely powerful but potentially dangerous tool. Use wisely.

Constructor Summary

Constructors

Constructor	Description
ObjectIntrospector(Object o)	Shortcut for calling new ObjectIntrospector(o, null);
ObjectIntrospector(Object object, ReaderParser parser)	Constructor.

Method Summary

Modifier and Type	Method	Description
static ObjectIntrospector	create(Object o)	Static creator.
static ObjectIntrospector	create(Object o, ReaderParser parser)	Static creator.
<T> T	invokeMethod(Class<T> returnType, Method method, Reader args)	Primary method.
<T> T	invokeMethod(Class<T> returnType, String method, String args)	Convenience method for invoking argument from method signature (@see MethodInfo.getSignature().
Object	invokeMethod(Method method, Reader args)	Primary method.
Object	invokeMethod(String method, String args)	Convenience method for invoking argument from method signature (@see MethodInfo.getSignature().

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

ObjectIntrospector

public ObjectIntrospector(Object o)

Shortcut for calling new ObjectIntrospector(o, null);

Parameters:

o - The object on which Java methods will be invoked.

ObjectIntrospector

public ObjectIntrospector(Object object,
 ReaderParser parser)

Constructor.

Parameters:

object - The object on which Java methods will be invoked.

parser - The parser to use to parse the method arguments. If null, JsonParser.DEFAULT is used.

Method Details

create

public static ObjectIntrospector create(Object o)

Static creator.

Parameters:

o - The object on which Java methods will be invoked.

Returns:

A new ObjectIntrospector object.

create

public static ObjectIntrospector create(Object o,
 ReaderParser parser)

Static creator.

Parameters:

o - The object on which Java methods will be invoked.

parser - The parser to use to parse the method arguments.

Returns:

A new ObjectIntrospector object.

invokeMethod

public <T> T invokeMethod(Class<T> returnType,
 Method method,
 Reader args)
                   throws InvocationTargetException,
IllegalArgumentException,
IllegalAccessException,
ParseException,
IOException

Primary method.

Invokes the specified method on this bean.

Type Parameters:

T - The return type of the method call.

Parameters:

returnType - The return type of the method call.

method - The method being invoked.

args - The arguments to pass as parameters to the method. These will automatically be converted to the appropriate object type if possible. Can be null if method has no arguments.

Returns:

The object returned by the call to the method, or null if target object is null.

Throws:

IllegalAccessException - If the Constructor object enforces Java language access control and the underlying constructor is inaccessible.

IllegalArgumentException - If one of the following occurs:

• The number of actual and formal parameters differ.
• An unwrapping conversion for primitive arguments fails.
• A parameter value cannot be converted to the corresponding formal parameter type by a method invocation conversion.
• The constructor pertains to an enum type.

InvocationTargetException - If the underlying constructor throws an exception.

ParseException - Malformed input encountered.

IOException - Thrown by underlying stream.

invokeMethod

public <T> T invokeMethod(Class<T> returnType,
 String method,
 String args)
                   throws NoSuchMethodException,
IllegalArgumentException,
InvocationTargetException,
IllegalAccessException,
ParseException,
IOException

Convenience method for invoking argument from method signature (@see MethodInfo.getSignature().

Type Parameters:

T - The return type of the method call.

Parameters:

returnType - The return type of the method call.

method - The method being invoked.

args - The arguments to pass as parameters to the method. These will automatically be converted to the appropriate object type if possible. Can be null if method has no arguments.

Returns:

The object returned by the call to the method, or null if target object is null.

Throws:

NoSuchMethodException - If method does not exist.

IllegalAccessException - If the Constructor object enforces Java language access control and the underlying constructor is inaccessible.

IllegalArgumentException - If one of the following occurs:

• The number of actual and formal parameters differ.
• An unwrapping conversion for primitive arguments fails.
• A parameter value cannot be converted to the corresponding formal parameter type by a method invocation conversion.
• The constructor pertains to an enum type.

InvocationTargetException - If the underlying constructor throws an exception.

ParseException - Malformed input encountered.

IOException - Thrown by underlying stream.

invokeMethod

public Object invokeMethod(Method method,
 Reader args)
                    throws InvocationTargetException,
IllegalArgumentException,
IllegalAccessException,
ParseException,
IOException

Primary method.

Invokes the specified method on this bean.

Parameters:

method - The method being invoked.

args - The arguments to pass as parameters to the method. These will automatically be converted to the appropriate object type if possible. Can be null if method has no arguments.

Returns:

The object returned by the call to the method, or null if target object is null.

Throws:

IllegalAccessException - If the Constructor object enforces Java language access control and the underlying constructor is inaccessible.

IllegalArgumentException - If one of the following occurs:

• The number of actual and formal parameters differ.
• An unwrapping conversion for primitive arguments fails.
• A parameter value cannot be converted to the corresponding formal parameter type by a method invocation conversion.
• The constructor pertains to an enum type.

InvocationTargetException - If the underlying constructor throws an exception.

ParseException - Malformed input encountered.

IOException - Thrown by underlying stream.

invokeMethod

public Object invokeMethod(String method,
 String args)
                    throws NoSuchMethodException,
IllegalArgumentException,
InvocationTargetException,
IllegalAccessException,
ParseException,
IOException

Convenience method for invoking argument from method signature (@see MethodInfo.getSignature().

Parameters:

method - The method being invoked.

args - The arguments to pass as parameters to the method. These will automatically be converted to the appropriate object type if possible. Can be null if method has no arguments.

Returns:

The object returned by the call to the method, or null if target object is null.

Throws:

NoSuchMethodException - If method does not exist.

IllegalAccessException - If the Constructor object enforces Java language access control and the underlying constructor is inaccessible.

IllegalArgumentException - If one of the following occurs:

• The number of actual and formal parameters differ.
• An unwrapping conversion for primitive arguments fails.
• A parameter value cannot be converted to the corresponding formal parameter type by a method invocation conversion.
• The constructor pertains to an enum type.

InvocationTargetException - If the underlying constructor throws an exception.

ParseException - Malformed input encountered.

IOException - Thrown by underlying stream.