Java Provides a technique for String Objects:
- String objects using
String.intern()method to forces JVM to check the internal list and use the existing String object if it is already present. - JVM maintains unique String objects for String literals internally
Example
/* This Program is make to understand the intern() method */
package StringProject;
public class Class1 {
public static void main(String[] args) {
/* making String Objects with value Hello */
String s1 =new String("Hello");
String s2= new String("Hello");
System.out.println("First String "+s1);
System.out.println("Second String "+s2);
/* Check both Strings are (== ) */
System.out.print("s1==s2 ?");
System.out.println( s1==s2);
/* check both Strings are (equal()) */
System.out.println("s1.equals(s2) ?" + s1.equalsIgnoreCase(s2));
System.out.println("After intern() method==");
/* calling of intern() method */
s2=s2.intern();
s1=s1.intern();
/* After intern() calling check String(==) */
System.out.print("s1==s2 ?");
System.out.println( s1==s2);
/* After intern() calling check String(equal()) */
System.out.println("s1.equals(s2) ?" + s1.equalsIgnoreCase(s2));
}
}
OUTPUT
After Interning the String Object:
String Literal and String Object Performance
Example
OUTPUT
/* This Program is Mainly for check the performance of both String Literals and
String Objects */
package StringProject;
public class Class1{
public static void main(String[] args){
System.out.println("Optimized Time Taken By String Literals and String Objects:");
/* To check performance */
long strttime1=System.currentTimeMillis();
/* Making String Literals */
for(int i=0;i<500000;i++)
{
String s1 ="Hello";
}
long endtime1=System.currentTimeMillis();
System.out.println("For String Literals Time Taken:"+(endtime1 - strttime1));
long strttime2=System.currentTimeMillis();
/* Making String Object */
for(int i=0;i<500000;i++)
{
String s2 =new String("Hello");
}
long endtime2=System.currentTimeMillis();
System.out.println("For String Objects Time Taken:"+(endtime2-strttime2));
}
}
OUTPUT
