如何用Java导入软件包 [英] How to import packages in Java

问题描述

大家好，
我对Java有一个疑问.
我在Java中有2个软件包.因为我已经将一个包装导入另一个包装
如下.

Hi All,
I have one doubt regarding Java.
I have 2 packages in java. In that i have imported one package into another
as follows.

package package1;
public class Base1{
public void Method1(){
System.out.println("Method1");
}
}

package package2;
import package1;
public class Base2{
public void Method2(){
System.out.println("Method2");
Base1 b1=new Base1();
b1.Method1();
}
}


import package2;
public class clsMain{
public static void main(String[] args){
Base2 b2=new Base2();
b2.Method2();
}
}

谁能告诉我这个
它显示了一些错误，如下所示
编译第二个文件Base2时，出现以下错误

Can any body tell me this
its showing some errors as follows
while compiling the second file Base2 the following error is coming

Base2.java:2: '.' expect
import Package1;

并且在编译clsMain文件时显示以下错误

and While compiling the clsMain file its showing following errors

clsMain.java:1: package package2 does not exist
import package.*;
^
.\Base21.java:2: '.' expected
import Package1;
             ^
Use.java:9: cannot access Base2
bad class file: .\Base2.java
file does not contain class Base2
Please remove or make sure it appears in
th.
                Base2 m = new Base2();

如果这有什么问题，您可以为这种情况提供代码吗?

If anything wrong is there in this can you give code for this scenario please

推荐答案

您不导入软件包.您将类导入包中.

因此，该格式为以下格式之一(方括号用来表示名称，而不是语法.)

You don''t import packages. You import classes in a package.

So the form is one of the following (brackets used to indicate a name not syntax.)

import {package}.*;
import {package}.{class name in package};

所以你会用

So you would use

import Package1.*;

还要注意，对于以后的问题，它有助于指定代码所在的文件.

Also note that for future questions it helps to specify the files in which your code is in.

有两种方法可以使用存储在包中的公共类.
a)声明完全合格的班级名称
...

There are 2 ways in order to use the public classes stored in package.
a) Declare the fully-qualified class name
...

world.HelloWorld helloWorld = new world.HelloWorld();
world.moon.HelloMoon helloMoon = new world.moon.HelloMoon();
String holeName = helloMoon.getHoleName();

b)使用导入"关键字

b) Use an "import" keyword

import world.*;  // we can call any public classes inside the world package
import world.moon.*;  // we can call any public classes inside the world.moon package
import java.util.*;  // import all public classes from java.util package

参考链接:-
http://www.jarticles.com/package/package_eng.html [使用包成员 [

Reference link :-
http://www.jarticles.com/package/package_eng.html[^]
Using Package Members[^]

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