字符串"true"转换为布尔型boolean「true」

public class dd {
public static void main(String []arg){
String s = "true";

boolean b = Boolean.valueOf("true").booleanValue();
System.out.println(b);

boolean b1 = Boolean.valueOf(s).booleanValue();
System.out.println(b1);

boolean b2 = Boolean.parseBoolean(s);
System.out.println(b2);

Boolean bb = new Boolean(s);
boolean b3 = bb.booleanValue();
System.out.println(b3);
}
}