Java程序代码记录一

package file;

public class J2 {
    public static void main(String[]args){
        Boolean b = new Boolean("true");
        boolean ret = b.booleanValue();
        System.out.print(ret);
    }

}

 1 package file;
 2 
 3 public class J2 {
 4     public static void main(String[]args){
 5         
 6         String s = "123";
 7         int a = Integer.parseInt(s);
 8         if(a == 123){
 9             System.out.println("now s==123");
10             System.out.println(Long.MAX_VALUE);
11             System.out.println(Long.MIN_VALUE);
12             System.out.println(Double.MAX_VALUE);
13             
14             Integer a1 = 5;//自动解包
15             int a2 = new Integer(5);//自动解包
16             
17             Boolean f = new Boolean("true");
18             boolean d = f.booleanValue();
19             
20         }
21     }
22 
23 }