1.String转int
Integer.parseInt(str);
2.int转String
String.valueOf(int)
3.String转char[]
String.toCharArray();
4.char[]转String
new String(char[])
5.String转StringBuilder
new StringBuilder(a);
6.StringBuilder转String
StringBuilder.toString();
原文：https://www.cnblogs.com/bocurry/p/13166971.html