Java Import Custom Class

Eclipse import is easy, yesterday in class learned to write Java with Notepad, import custom classes, which is troublesome.

Code paste, easy to operate:

 PackageTom.jiafei; Public classsquareequation {DoubleA,b,c; DoubleRoot1,root2; BooleanBoo;  PublicSquareequation (DoubleADoubleBDoublec) { This. A =A;  This. B =b;  This. C =C; if(a!=0) Boo =true; ElseBoo =false; }         Public voidSetcoefficient (DoubleADoubleBDoublec) { This. A =A;  This. B =b;  This. C =C; if(a!=0) Boo=true; ElseBoo =false; }         Public voidgetroots () {if(Boo) {System.out.println ("Shi er yuan Fang Chen Shi"); DoubleDisk = b*b-4*a*C; if(disk>=0) {root1= (-b+math.sqrt (disk)/(a)); Root2= (-b-math.sqrt (disk)/(a)); System.out.println ("The Roots is" +root1+ "" +Root2); }            ElseSystem.out.println ("Mei You Jie"); }        Else{System.out.println ("Bu shi er yuan fang Chen Shi Gen"); }            }                                }

View Code

import tom.jiafei.*;  Public class SunRise {    /**     @param  args     * /     Publicstaticvoid  main (string[] args) {        new squareequation (4 , 5, 1);        Equation.getroots ();        Equation.setcoefficient (-3, 4, 5);        Equation.getroots ();    }}

View Code

Direct:

C Disk has a two-yuan equation of the packet class, package name Tom.jiafei, compile, put the. class file into the Tom\jiafei directory.

D disk has a main function to use this class, first reset Classpath. hit a set classpath = .... \jre\lib\rt.jar;.; C:\1000

Then modify the environment variable set classpath = .... \jre\lib\rt.jar;.; C:\1000

Compile and run the main function.

Install Java, system default Classpath =....\jre\lib\rt.jar;.;

Indicates that the application can use the Nameless package class under the current directory, and the named Package (and corresponding) under the subdirectory.

If the application is to use a class that does not meet the above criteria, it is necessary to reset the classpath. Add a parameter, which is the top-level directory of the package name.

Conversely, if you meet the conditions, you don't have to be so troublesome, you can compile the main function directly.

Java import custom class