C:\Users\jaina_000\Desktop\learn_java\p1>javac Testp1.java
Testp1.java:6: error: cannot find symbol
Protection ob = new Protection();
^
symbol: class Protection
location: class Testp1
Testp1.java:6: error: cannot find symbol
Protection ob = new Protection();
^
symbol: class Protection
location: class Testp1
Testp1.java:7: error: cannot find symbol
Derived ob1 = new Derived();
^
symbol: class Derived
location: class Testp1
Testp1.java:7: error: cannot find symbol
Derived ob1 = new Derived();
^
symbol: class Derived
location: class Testp1
Testp1.java:8: error: cannot find symbol
SamePackage ob2 = new SamePackage();
^
symbol: class SamePackage
location: class Testp1
Testp1.java:8: error: cannot find symbol
SamePackage ob2 = new SamePackage();
^
symbol: class SamePackage
location: class Testp1
6 errors
package p1;
public class Testp1
{
public static void main(String a[])
{
Protection ob = new Protection();
Derived ob1 = new Derived();
SamePackage ob2 = new SamePackage();
}
}
package p1;
public class Protection
{
int n = 1;
private int n_pri = 2;
protected int n_pro = 3;
public int n_pub = 4;
public Protection()
{
System.out.println("Inside base constructor.");
System.out.println(" n = "+n);
System.out.println("n_pri = "+n_pri);
System.out.println("n_pro = "+n_pro);
System.out.println("n_pub = "+n_pub);
}
}
package p1;
class Derived extends Protection
{
Derived()
{
System.out.println("Inside Derived constructor.");
System.out.println(" n = "+n);
// System.out.println("n_pri = "+n_pri);
System.out.println("n_pro = "+n_pro);
System.out.println("n_pub = "+n_pub);
}
}
package p1;
class SamePackage{
SamePackage(){
Protection p = new Protection();
System.out.println("Inside SamePackage constructor.");
System.out.println(" n = "+p.n);
// System.out.println("n_pri = "+p.n_pri);
System.out.println("n_pro = "+p.n_pro);
System.out.println("n_pub = "+p.n_pub);
}
}
最佳答案
当你有 package 时，你不能像在没有 package 的类中那样简单地编译或运行。
编译时，您需要导航到包文件夹外部，然后使用命令 javac [package]/[class] 进行编译。因此在您的情况下，它应该是
javac p1/Testp1.java
运行时使用此命令java[package.class]..所以在你的情况下它应该是
java p1.Testp1
确保您不在包 [p1] 内，您应该在包外部 [通过 cmd 导航到文件夹 learn_java 后进行编译]。
最后这就是你的 cmd 的样子
C:\Users\jaina_000\Desktop\learn_java>javac p1/Testp1.java C:\Users\jaina_000\Desktop\learn_java>java p1.Testp1 Inside base constructor. n = 1 n_pri = 2 n_pro = 3 n_pub = 4 Inside base constructor. n = 1 n_pri = 2 n_pro = 3 n_pub = 4 Inside Derived constructor. n = 1 n_pro = 3 n_pub = 4 Inside base constructor. n = 1 n_pri = 2 n_pro = 3 n_pub = 4 Inside SamePackage constructor. n = 1 n_pro = 3 n_pub = 4 C:\Users\jaina_000\Desktop\learn_java>
关于java - 访问说明符错误(找不到符号)，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27508886/