Package org.apache.commons.lang

Class ObjectUtils

  • @Deprecated(since="2021-04-30")
public class ObjectUtils
extends java.lang.Object
    Deprecated.

    Operations on Object.

    This class tries to handle null input gracefully. An exception will generally not be thrown for a null input. Each method documents its behaviour in more detail.

    #ThreadSafe#

    Since:
    1.0

    • Nested Class Summary

      Nested Classes 
      Modifier and Type Class Description
      static class  ObjectUtils.Null
      Deprecated.
      Commons Lang 2 is in maintenance mode.

    • Field Summary

      Fields 
      Modifier and Type Field Description
      static ObjectUtils.Null NULL
      Deprecated.
      Singleton used as a null placeholder where null has another meaning.

    • Constructor Summary

      Constructors 
      Constructor Description
      ObjectUtils()
      Deprecated.
      ObjectUtils instances should NOT be constructed in standard programming.

    • Method Summary

      All Methods Static Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      static java.lang.StringBuffer appendIdentityToString​(java.lang.StringBuffer buffer, java.lang.Object object)
      Deprecated.
      The design of this method is bad - see LANG-360.
      static java.lang.Object clone​(java.lang.Object o)
      Deprecated.
      Clone an object.
      static java.lang.Object cloneIfPossible​(java.lang.Object o)
      Deprecated.
      Clone an object if possible.
      static int compare​(java.lang.Comparable c1, java.lang.Comparable c2)
      Deprecated.
      Null safe comparison of Comparables.
      static int compare​(java.lang.Comparable c1, java.lang.Comparable c2, boolean nullGreater)
      Deprecated.
      Null safe comparison of Comparables.
      static java.lang.Object defaultIfNull​(java.lang.Object object, java.lang.Object defaultValue)
      Deprecated.
      Returns a default value if the object passed is null.
      static boolean equals​(java.lang.Object object1, java.lang.Object object2)
      Deprecated.
      Compares two objects for equality, where either one or both objects may be null.
      static int hashCode​(java.lang.Object obj)
      Deprecated.
      Gets the hash code of an object returning zero when the object is null.
      static java.lang.String identityToString​(java.lang.Object object)
      Deprecated.
      Gets the toString that would be produced by Object if a class did not override toString itself.
      static void identityToString​(java.lang.StringBuffer buffer, java.lang.Object object)
      Deprecated.
      Appends the toString that would be produced by Object if a class did not override toString itself.
      static java.lang.Object max​(java.lang.Comparable c1, java.lang.Comparable c2)
      Deprecated.
      Null safe comparison of Comparables.
      static java.lang.Object min​(java.lang.Comparable c1, java.lang.Comparable c2)
      Deprecated.
      Null safe comparison of Comparables.
      static boolean notEqual​(java.lang.Object object1, java.lang.Object object2)
      Deprecated.
      Compares two objects for inequality, where either one or both objects may be null.
      static java.lang.String toString​(java.lang.Object obj)
      Deprecated.
      Gets the toString of an Object returning an empty string ("") if null input.
      static java.lang.String toString​(java.lang.Object obj, java.lang.String nullStr)
      Deprecated.
      Gets the toString of an Object returning a specified text if null input.

      • Methods inherited from class java.lang.Object

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

    • Field Detail

      • NULL

        public static final ObjectUtils.Null NULL
        Deprecated.

        Singleton used as a null placeholder where null has another meaning.

        For example, in a HashMap the HashMap.get(java.lang.Object) method returns null if the Map contains null or if there is no matching key. The Null placeholder can be used to distinguish between these two cases.

        Another example is Hashtable, where null cannot be stored.

        This instance is Serializable.

    • Constructor Detail

      • ObjectUtils

        public ObjectUtils()
        Deprecated.

        ObjectUtils instances should NOT be constructed in standard programming. Instead, the class should be used as ObjectUtils.defaultIfNull("a","b");.

        This constructor is public to permit tools that require a JavaBean instance to operate.

    • Method Detail

      • defaultIfNull

        public static java.lang.Object defaultIfNull​(java.lang.Object object,
                                             java.lang.Object defaultValue)
        Deprecated.

        Returns a default value if the object passed is null.

         ObjectUtils.defaultIfNull(null, null)      = null
 ObjectUtils.defaultIfNull(null, "")        = ""
 ObjectUtils.defaultIfNull(null, "zz")      = "zz"
 ObjectUtils.defaultIfNull("abc", *)        = "abc"
 ObjectUtils.defaultIfNull(Boolean.TRUE, *) = Boolean.TRUE
        Parameters:
        object - the Object to test, may be null
        defaultValue - the default value to return, may be null
        Returns:
        object if it is not null, defaultValue otherwise

      • equals

        public static boolean equals​(java.lang.Object object1,
                             java.lang.Object object2)
        Deprecated.

        Compares two objects for equality, where either one or both objects may be null.

         ObjectUtils.equals(null, null)                  = true
 ObjectUtils.equals(null, "")                    = false
 ObjectUtils.equals("", null)                    = false
 ObjectUtils.equals("", "")                      = true
 ObjectUtils.equals(Boolean.TRUE, null)          = false
 ObjectUtils.equals(Boolean.TRUE, "true")        = false
 ObjectUtils.equals(Boolean.TRUE, Boolean.TRUE)  = true
 ObjectUtils.equals(Boolean.TRUE, Boolean.FALSE) = false
        Parameters:
        object1 - the first object, may be null
        object2 - the second object, may be null
        Returns:
        true if the values of both objects are the same

      • notEqual

        public static boolean notEqual​(java.lang.Object object1,
                               java.lang.Object object2)
        Deprecated.

        Compares two objects for inequality, where either one or both objects may be null.

         ObjectUtils.notEqual(null, null)                  = false
 ObjectUtils.notEqual(null, "")                    = true
 ObjectUtils.notEqual("", null)                    = true
 ObjectUtils.notEqual("", "")                      = false
 ObjectUtils.notEqual(Boolean.TRUE, null)          = true
 ObjectUtils.notEqual(Boolean.TRUE, "true")        = true
 ObjectUtils.notEqual(Boolean.TRUE, Boolean.TRUE)  = false
 ObjectUtils.notEqual(Boolean.TRUE, Boolean.FALSE) = true
        Parameters:
        object1 - the first object, may be null
        object2 - the second object, may be null
        Returns:
        false if the values of both objects are the same
        Since:
        2.6

      • hashCode

        public static int hashCode​(java.lang.Object obj)
        Deprecated.

        Gets the hash code of an object returning zero when the object is null.

         ObjectUtils.hashCode(null)   = 0
 ObjectUtils.hashCode(obj)    = obj.hashCode()
        Parameters:
        obj - the object to obtain the hash code of, may be null
        Returns:
        the hash code of the object, or zero if null
        Since:
        2.1

      • identityToString

        public static java.lang.String identityToString​(java.lang.Object object)
        Deprecated.

        Gets the toString that would be produced by Object if a class did not override toString itself. null will return null.

         ObjectUtils.identityToString(null)         = null
 ObjectUtils.identityToString("")           = "java.lang.String@1e23"
 ObjectUtils.identityToString(Boolean.TRUE) = "java.lang.Boolean@7fa"
        Parameters:
        object - the object to create a toString for, may be null
        Returns:
        the default toString text, or null if null passed in

      • identityToString

        public static void identityToString​(java.lang.StringBuffer buffer,
                                    java.lang.Object object)
        Deprecated.

        Appends the toString that would be produced by Object if a class did not override toString itself. null will throw a NullPointerException for either of the two parameters. 

         ObjectUtils.identityToString(buf, "")            = buf.append("java.lang.String@1e23"
 ObjectUtils.identityToString(buf, Boolean.TRUE)  = buf.append("java.lang.Boolean@7fa"
 ObjectUtils.identityToString(buf, Boolean.TRUE)  = buf.append("java.lang.Boolean@7fa")
        Parameters:
        buffer - the buffer to append to
        object - the object to create a toString for
        Since:
        2.4

      • appendIdentityToString

        public static java.lang.StringBuffer appendIdentityToString​(java.lang.StringBuffer buffer,
                                                            java.lang.Object object)
        Deprecated.
        The design of this method is bad - see LANG-360. Instead, use identityToString(StringBuffer, Object).

        Appends the toString that would be produced by Object if a class did not override toString itself. null will return null.

         ObjectUtils.appendIdentityToString(*, null)            = null
 ObjectUtils.appendIdentityToString(null, "")           = "java.lang.String@1e23"
 ObjectUtils.appendIdentityToString(null, Boolean.TRUE) = "java.lang.Boolean@7fa"
 ObjectUtils.appendIdentityToString(buf, Boolean.TRUE)  = buf.append("java.lang.Boolean@7fa")
        Parameters:
        buffer - the buffer to append to, may be null
        object - the object to create a toString for, may be null
        Returns:
        the default toString text, or null if null passed in
        Since:
        2.0

      • toString

        public static java.lang.String toString​(java.lang.Object obj)
        Deprecated.

        Gets the toString of an Object returning an empty string ("") if null input.

         ObjectUtils.toString(null)         = ""
 ObjectUtils.toString("")           = ""
 ObjectUtils.toString("bat")        = "bat"
 ObjectUtils.toString(Boolean.TRUE) = "true"
        Parameters:
        obj - the Object to toString, may be null
        Returns:
        the passed in Object's toString, or nullStr if null input
        Since:
        2.0
        See Also:
        StringUtils.defaultString(String), String.valueOf(Object)

      • toString

        public static java.lang.String toString​(java.lang.Object obj,
                                        java.lang.String nullStr)
        Deprecated.

        Gets the toString of an Object returning a specified text if null input.

         ObjectUtils.toString(null, null)           = null
 ObjectUtils.toString(null, "null")         = "null"
 ObjectUtils.toString("", "null")           = ""
 ObjectUtils.toString("bat", "null")        = "bat"
 ObjectUtils.toString(Boolean.TRUE, "null") = "true"
        Parameters:
        obj - the Object to toString, may be null
        nullStr - the String to return if null input, may be null
        Returns:
        the passed in Object's toString, or nullStr if null input
        Since:
        2.0
        See Also:
        StringUtils.defaultString(String,String), String.valueOf(Object)

      • min

        public static java.lang.Object min​(java.lang.Comparable c1,
                                   java.lang.Comparable c2)
        Deprecated.
        Null safe comparison of Comparables.
        Parameters:
        c1 - the first comparable, may be null
        c2 - the second comparable, may be null
        Returns:
        • If both objects are non-null and unequal, the lesser object.
        • If both objects are non-null and equal, c1.
        • If one of the comparables is null, the non-null object.
        • If both the comparables are null, null is returned.

      • max

        public static java.lang.Object max​(java.lang.Comparable c1,
                                   java.lang.Comparable c2)
        Deprecated.
        Null safe comparison of Comparables.
        Parameters:
        c1 - the first comparable, may be null
        c2 - the second comparable, may be null
        Returns:
        • If both objects are non-null and unequal, the greater object.
        • If both objects are non-null and equal, c1.
        • If one of the comparables is null, the non-null object.
        • If both the comparables are null, null is returned.

      • compare

        public static int compare​(java.lang.Comparable c1,
                          java.lang.Comparable c2)
        Deprecated.
        Null safe comparison of Comparables. null is assumed to be less than a non-null value.
        Parameters:
        c1 - the first comparable, may be null
        c2 - the second comparable, may be null
        Returns:
        a negative value if c1 < c2, zero if c1 = c2 and a positive value if c1 > c2
        Since:
        2.6

      • compare

        public static int compare​(java.lang.Comparable c1,
                          java.lang.Comparable c2,
                          boolean nullGreater)
        Deprecated.
        Null safe comparison of Comparables.
        Parameters:
        c1 - the first comparable, may be null
        c2 - the second comparable, may be null
        nullGreater - if true null is considered greater than a Non-null value or if false null is considered less than a Non-null value
        Returns:
        a negative value if c1 < c2, zero if c1 = c2 and a positive value if c1 > c2
        Since:
        2.6
        See Also:
        Comparator.compare(Object, Object)

      • clone

        public static java.lang.Object clone​(java.lang.Object o)
        Deprecated.
        Clone an object.
        Parameters:
        o - the object to clone
        Returns:
        the clone if the object implements Cloneable otherwise null
        Throws:
        CloneFailedException - if the object is cloneable and the clone operation fails
        Since:
        2.6

      • cloneIfPossible

        public static java.lang.Object cloneIfPossible​(java.lang.Object o)
        Deprecated.
        Clone an object if possible. This method is similar to clone(Object), but will return the provided instance as the return value instead of null if the instance is not cloneable. This is more convenient if the caller uses different implementations (e.g. of a service) and some of the implementations do not allow concurrent processing or have state. In such cases the implementation can simply provide a proper clone implementation and the caller's code does not have to change.
        Parameters:
        o - the object to clone
        Returns:
        the clone if the object implements Cloneable otherwise the object itself
        Throws:
        CloneFailedException - if the object is cloneable and the clone operation fails
        Since:
        2.6