java.lang.Boolean.valueOf(String s)

简单说，就是s为true（这四个字母大小写任意）时，返回值为true，否则为false

 public class one {

     public static void main(String[] args) {
           Boolean b1, b2;

           // create 2 String's and assign values
           String s1 = null;
           String s2 = "truE";

           /**
            *  static method is called using class name
            *  assign result of valueOf method on s1, s2 to b1, b2
            */
           b1 = Boolean.valueOf(s1);
           b2 = Boolean.valueOf(s2);

           System.out.println(b1);
           System.out.println(b2);
           String str1 = "Boolean instance of string " + s1 + " is "  + b1;
           String str2 = "Boolean instance of string " + s2 + " is "  + b2;

           // print b1, b2 values
           System.out.println( str1 );
           System.out.println( str2 );
     }
 }

执行结果为：