String与Integer互相转换

//String转换Integer
String str = "a";
Integer i = null;
if(str!=null){
     i = Integer.valueOf(str);
}

//方法一:Integer类的静态方法toString():
Integer a = 2;
String str = Integer.toString(a)

//方法二:Integer类的成员方法toString():
Integer b = 2;
String str = b.toString();

//方法三:String类的静态方法valueOf():
Integer c = 2;
String str = String.valueOf(c);