long a1 = 12;
String s1 = a1 + ""; // 法1:直接加空串
System.out.println(s1);
long a2 = 34;
String s2 = String.valueOf(a2); // 法2:String.valueOf()
System.out.println(s2);
long a3 = 56;
String s3 = Long.toString(a3); // 法3:Long.toString()
System.out.println(s3);
转载:https://blog.youkuaiyun.com/kzadmxz/article/details/80600145