Java by API/org.apache.commons.lang/ObjectUtils
Содержание
ObjectUtils: defaultIfNull(Object object, Object defaultValue)
<source lang="java">
/* 1) If null return DEFAULT >>>DEFAULT 2) References to the same object >>>true 3) Check object references and not values >>>true 4) toSring gets invoked >>> 5) Display object details >>>java.lang.String@93dcd 6) Pass null and get back an Empty string >>>****
- /
import org.apache.rumons.lang.ObjectUtils; public class ObjectUtilsTrial {
public static void main(String[] args) {
// Create ObjectUtilsTrial instance
String one = new String();
String two = one; // Same Reference
String three = new String(); // New Object
String four = null;
// four is null, returns DEFAULT
System.out.print("1) If null return DEFAULT >>>");
System.out.println(ObjectUtils.defaultIfNull(four, "DEFAULT"));
// one and two point to the same object
System.out.print("2) References to the same object >>>");
System.out.println(ObjectUtils.equals(one, two));
// one and three are different objects
System.out.print("3) Check object references and not values >>>");
System.out.println(ObjectUtils.equals(one, three));
// toString method gets called
System.out.print("4) toSring gets invoked >>>");
System.out.println(one);
// Object details displayed..toString is not called
System.out.print("5) Display object details >>>");
System.out.println(ObjectUtils.identityToString(one));
// Pass null get empty string
System.out.print("6) Pass null and get back an Empty string >>>");
System.out.println("**" + ObjectUtils.toString(null) + "**");
}
public String toString() {
return "toString Output";
}
}
</source>
ObjectUtils: equals(Object object1, Object object2)
<source lang="java">
/* 1) If null return DEFAULT >>>DEFAULT 2) References to the same object >>>true 3) Check object references and not values >>>true 4) toSring gets invoked >>> 5) Display object details >>>java.lang.String@93dcd 6) Pass null and get back an Empty string >>>****
- /
import org.apache.rumons.lang.ObjectUtils; public class ObjectUtilsTrial {
public static void main(String[] args) {
// Create ObjectUtilsTrial instance
String one = new String();
String two = one; // Same Reference
String three = new String(); // New Object
String four = null;
// four is null, returns DEFAULT
System.out.print("1) If null return DEFAULT >>>");
System.out.println(ObjectUtils.defaultIfNull(four, "DEFAULT"));
// one and two point to the same object
System.out.print("2) References to the same object >>>");
System.out.println(ObjectUtils.equals(one, two));
// one and three are different objects
System.out.print("3) Check object references and not values >>>");
System.out.println(ObjectUtils.equals(one, three));
// toString method gets called
System.out.print("4) toSring gets invoked >>>");
System.out.println(one);
// Object details displayed..toString is not called
System.out.print("5) Display object details >>>");
System.out.println(ObjectUtils.identityToString(one));
// Pass null get empty string
System.out.print("6) Pass null and get back an Empty string >>>");
System.out.println("**" + ObjectUtils.toString(null) + "**");
}
public String toString() {
return "toString Output";
}
}
</source>
ObjectUtils: identityToString(Object obj)
<source lang="java">
/* 1) If null return DEFAULT >>>DEFAULT 2) References to the same object >>>true 3) Check object references and not values >>>true 4) toSring gets invoked >>> 5) Display object details >>>java.lang.String@93dcd 6) Pass null and get back an Empty string >>>****
- /
import org.apache.rumons.lang.ObjectUtils; public class ObjectUtilsTrial {
public static void main(String[] args) {
// Create ObjectUtilsTrial instance
String one = new String();
String two = one; // Same Reference
String three = new String(); // New Object
String four = null;
// four is null, returns DEFAULT
System.out.print("1) If null return DEFAULT >>>");
System.out.println(ObjectUtils.defaultIfNull(four, "DEFAULT"));
// one and two point to the same object
System.out.print("2) References to the same object >>>");
System.out.println(ObjectUtils.equals(one, two));
// one and three are different objects
System.out.print("3) Check object references and not values >>>");
System.out.println(ObjectUtils.equals(one, three));
// toString method gets called
System.out.print("4) toSring gets invoked >>>");
System.out.println(one);
// Object details displayed..toString is not called
System.out.print("5) Display object details >>>");
System.out.println(ObjectUtils.identityToString(one));
// Pass null get empty string
System.out.print("6) Pass null and get back an Empty string >>>");
System.out.println("**" + ObjectUtils.toString(null) + "**");
}
public String toString() {
return "toString Output";
}
}
</source>
ObjectUtils: toString(Object obj)
<source lang="java">
/* 1) If null return DEFAULT >>>DEFAULT 2) References to the same object >>>true 3) Check object references and not values >>>true 4) toSring gets invoked >>> 5) Display object details >>>java.lang.String@93dcd 6) Pass null and get back an Empty string >>>****
- /
import org.apache.rumons.lang.ObjectUtils; public class ObjectUtilsTrial {
public static void main(String[] args) {
// Create ObjectUtilsTrial instance
String one = new String();
String two = one; // Same Reference
String three = new String(); // New Object
String four = null;
// four is null, returns DEFAULT
System.out.print("1) If null return DEFAULT >>>");
System.out.println(ObjectUtils.defaultIfNull(four, "DEFAULT"));
// one and two point to the same object
System.out.print("2) References to the same object >>>");
System.out.println(ObjectUtils.equals(one, two));
// one and three are different objects
System.out.print("3) Check object references and not values >>>");
System.out.println(ObjectUtils.equals(one, three));
// toString method gets called
System.out.print("4) toSring gets invoked >>>");
System.out.println(one);
// Object details displayed..toString is not called
System.out.print("5) Display object details >>>");
System.out.println(ObjectUtils.identityToString(one));
// Pass null get empty string
System.out.print("6) Pass null and get back an Empty string >>>");
System.out.println("**" + ObjectUtils.toString(null) + "**");
}
public String toString() {
return "toString Output";
}
}
</source>
