Field

Field

java.lang.reflect

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Java 1.1

This class represents a field of a class. Instances of Field are obtained by calling the getField( ) and related methods of java.lang.Class . Field implements the Member interface, so once you have obtained a Field object, you can use getName( ) , getModifiers( ) , and getdeclaringClass( ) to determine the name , modifiers, and class of the field. Additionally, getType( ) returns the type of the field.

The set( ) method sets the value of the represented field for a specified object. (If the represented field is static , no object need be specified, of course.) If the field is of a primitive type, its value can be specified using a wrapper object of type Boolean , Integer , and so on, or it can be set using the setBoolean( ) , setInt( ) , and related methods. Similarly, the get( ) method queries the value of the represented field for a specified object and returns the field value as an Object . Various other methods query the field value and return it as various primitive types.

In Java 5.0, Field implements AnnotatedElement to support reflection on field annotations. The new getGenericType( ) method supports reflection on the generic type of fields, and isEnumConstant( ) supports fields of enum types.

Figure 10-93. java.lang.reflect.Field

 public final class  Field  extends AccessibleObject implements Member {  // No Constructor   // Public Instance Methods  public Object  get  (Object  obj  )  throws IllegalArgumentException, IllegalAccessException;        public boolean  getBoolean  (Object  obj  )  throws IllegalArgumentException, IllegalAccessException;        public byte  getByte  (Object  obj  )  throws IllegalArgumentException, IllegalAccessException;        public char  getChar  (Object  obj  )  throws IllegalArgumentException, IllegalAccessException;        public double  getDouble  (Object  obj  )  throws IllegalArgumentException, IllegalAccessException;        public float  getFloat  (Object  obj  )  throws IllegalArgumentException, IllegalAccessException;  5.0  public Type  getGenericType  ( );        public int  getInt  (Object  obj  )  throws IllegalArgumentException, IllegalAccessException;        public long  getLong  (Object  obj  )  throws IllegalArgumentException, IllegalAccessException;        public short  getShort  (Object  obj  )  throws IllegalArgumentException, IllegalAccessException;        public Class<?>  getType  ( );  5.0  public boolean  isEnumConstant  ( );        public void  set  (Object  obj  , Object  value  )  throws IllegalArgumentException, IllegalAccessException;        public void  setBoolean  (Object  obj  , boolean  z  )  throws IllegalArgumentException, IllegalAccessException;        public void  setByte  (Object  obj  , byte  b  )  throws IllegalArgumentException, IllegalAccessException;        public void  setChar  (Object  obj  , char  c  )  throws IllegalArgumentException, IllegalAccessException;        public void  setDouble  (Object  obj  , double  d  )  throws IllegalArgumentException, IllegalAccessException;        public void  setFloat  (Object  obj  , float  f  )  throws IllegalArgumentException, IllegalAccessException;        public void  setInt  (Object  obj  , int  i  )  throws IllegalArgumentException, IllegalAccessException;        public void  setLong  (Object  obj  , long  l  )  throws IllegalArgumentException, IllegalAccessException;        public void  setShort  (Object  obj  , short  s  )  throws IllegalArgumentException, IllegalAccessException;  5.0  public String  toGenericString  ( );  // Methods Implementing Member  public Class<?>  getDeclaringClass  ( );        public int  getModifiers  ( );        public String  getName  ( );  5.0  public boolean  isSynthetic  ( );  // Public Methods Overriding AccessibleObject   5.0  public <T extends java.lang.annotation.Annotation> T  getAnnotation  (Class<T>  annotationClass  );  5.0  public java.lang.annotation.Annotation[ ]  getDeclaredAnnotations  ( );  // Public Methods Overriding Object  public boolean  equals  (Object  obj  );        public int  hashCode  ( );        public String  toString  ( );   } 

Returned By

Class.{getDeclaredField( ) , getdeclaredFields( ) , getField( ) , getFields( )}