JDK8源码
/**
* Returns an {@code Integer} object holding the value
* extracted from the specified {@code String} when parsed
* with the radix given by the second argument. The first argument
* is interpreted as representing a signed integer in the radix
* specified by the second argument, exactly as if the arguments
* were given to the {@link #parseInt(java.lang.String, int)}
* method. The result is an {@code Integer} object that
* represents the integer value specified by the string.
*
*
In other words, this method returns an {@code Integer}
* object equal to the value of:
*
*
* {@code new Integer(Integer.parseInt(s, radix))}
*
*
* @param s the string to be parsed.
* @param radix the radix to be used in interpreting {@code s}
* @return an {@code Integer} object holding the value
* represented by the string argument in the specified
* radix.
* @exception NumberFormatException if the {@code String}
* does not contain a parsable {@code int}.
*/
public static Integer valueOf(String s, int radix) throws NumberFormatException {
return Integer.valueOf(parseInt(s,radix));
}
这里用Inteager来说明， valueOf 实际上调用了 parseInt。
parseInt方法是类Integer的静态方法，它的作用就是将字符串转化为整数int
valueOf也是Integer类的静态方法，它的作用是将字符串转化为Integer对象
