Java java.beans Class Statement（JDK8）

Constructor Detail

• Statement

  @ConstructorProperties(value={"target","methodName","arguments"})
  public Statement(Object target,
                                                                                     String methodName,
                                                                                     Object[] arguments)

  Creates a new Statement object for the specified target object to invoke the method specified by the name and by the array of arguments.

  The target and the methodName values should not be null. Otherwise an attempt to execute this Expression will result in a NullPointerException. If the arguments value is null, an empty array is used as the value of the arguments property.

  Parameters:

  target - the target object of this statement

  methodName - the name of the method to invoke on the specified target

  arguments - the array of arguments to invoke the specified method

Method Detail

• getTarget

  public Object getTarget()

  Returns the target object of this statement. If this method returns null, the execute() method throws a NullPointerException.

  Returns:

  the target object of this statement

• getMethodName

  public String getMethodName()

  Returns the name of the method to invoke. If this method returns null, the execute() method throws a NullPointerException.

  Returns:

  the name of the method

• getArguments

  public Object[] getArguments()

  Returns the arguments for the method to invoke. The number of arguments and their types must match the method being called. null can be used as a synonym of an empty array.

  Returns:

  the array of arguments

• execute

  public void execute()
               throws Exception

  The execute method finds a method whose name is the same as the methodName property, and invokes the method on the target. When the target's class defines many methods with the given name the implementation should choose the most specific method using the algorithm specified in the Java Language Specification (15.11). The dynamic class of the target and arguments are used in place of the compile-time type information and, like the Method class itself, conversion between primitive values and their associated wrapper classes is handled internally.

  The following method types are handled as special cases:

  • Static methods may be called by using a class object as the target.
  • The reserved method name "new" may be used to call a class's constructor as if all classes defined static "new" methods. Constructor invocations are typically considered Expressions rather than Statements as they return a value.
  • The method names "get" and "set" defined in the List interface may also be applied to array instances, mapping to the static methods of the same name in the Array class.

  Throws:

  NullPointerException - if the value of the target or methodName property is null

  NoSuchMethodException - if a matching method is not found

  SecurityException - if a security manager exists and it denies the method invocation

  Exception - that is thrown by the invoked method

  See Also:

  Method

• toString

  public String toString()

  Prints the value of this statement using a Java-style syntax.

  Overrides:

  toString in class Object

  Returns:

  a string representation of the object.