常量池相关问题

String常量池问题的几个例子
示例1：
Java代码
String s0="kvill";
String s1="kvill";
String s2="kv" + "ill";
System.out.println( s0==s1 );
System.out.println( s0==s2 );
结果为：
true
true
示例2：
示例：
Java代码
String s0="kvill";
String s1=new String("kvill");
String s2="kv" + new String("ill");
System.out.println( s0==s1 );
System.out.println( s0==s2 );
System.out.println( s1==s2 );
结果为：
false
false
false
示例3：
Java代码
String a = "a1";
String b = "a" + 1;
System.out.println((a == b)); //result = true
String a = "atrue";
String b = "a" + "true";
System.out.println((a == b)); //result = true
String a = "a3.4";
String b = "a" + 3.4;
System.out.println((a == b)); //result = true
示例4：
Java代码
String a = "ab";
String bb = "b";
String b = "a" + bb;
System.out.println((a == b)); //result = false
示例5：
Java代码
String a = "ab";
final String bb = "b";
String b = "a" + bb;
System.out.println((a == b)); //result = true
示例6：
Java代码
String a = "ab";
final String bb = getBB();
String b = "a" + bb;
System.out.println((a == b)); //result = false
private static String getBB() {  return "b";   }