学习JAVA编程思想不久,JDK安装和环境设置都会呢,可在运行书上的实例的时候却出现问题,大概知道CLASSPATH的问题,如图:
//: c02:HelloDate.javaimport java.util.*; //如何设置CLASSPATH,能够导入util.*
public class HelloDate {
public static void main(String[] args) {
System.out.println("Hello, it's: ");
System.out.println(new Date());
}
} //error:can't read HelloData.java
//: c02:HelloDate.javaimport java.util.*; //如何设置CLASSPATH,能够导入util.*
public class HelloDate {
public static void main(String[] args) {
System.out.println("Hello, it's: ");
System.out.println(new Date());
}
} //error:can't read HelloData.java
==============================================
跟Classpath 可是没多大相关,你的文件名和你的类名直接不相同,一个是HelloData.java一个是HelloDate
class DataOnly {
int i;
float f;
boolean b;
}public class DataOnlyTest {
public static void main(String[] args) {
DataOnly d = new DataOnly();
d.i = 47;
d.f = 1.1f;
d.b = false;
}
} ///:~
那些applet,util.awt,sql,text....文件的的路径怎么设置或者说放在哪个位置才可以让编译器可以找到它呢
例如这个源程序:
import com.bruceeckel.simpletest.*; //问题在这..要导入包的程序public class Overflow {
static Test monitor = new Test();
public static void main(String[] args) {
int big = 0x7fffffff; // max int value
System.out.println("big = " + big);
int bigger = big * 4;
System.out.println("bigger = " + bigger);
monitor.expect(new String[] {
"big = 2147483647",
"bigger = -4"
});
}
} ///:~
错误提示: pocket com.bruceeckel.simpletest does not exit..
can't resolve symbol..
但是你的命令行用的应该是javac HelloDate.java
那么你不用IDE,在命令行下就要用-classpathjavac -classpath D:\java; HelloDate.java-classpath会覆盖环境变量的设置
你的文件名是HelloDate,而你的下面输入的是:HelloData.java
//error:can't read HelloData.java
当然读不到文件啊