Java编译错误 'package does not exist'

Question

我创建了两个packages.class 文件(util.Displayable 和 school.Teacher)。 Teacher 类将实现 util 中的 Displayable 接口(interface)。当我编译它时，我收到“teacher.java:2: 错误:package util 不存在”。其他错误是由于 util 包“不存在”造成的。我删除了 util 文件并再次尝试，但出现了相同的错误。关于为什么找不到 util 包的任何想法？ 谢谢!

util.Displayable 文件

package util;

public interface Displayable {
    public abstract String display();
}

学校.教师文件

package school;
import util.Displayable;

  public class Teacher extends Person implements Displayable {
    private String subject;

    public Teacher() {
    }

    public Teacher (String firstName, String lastName, String subject){
        this.setFirstName(firstName);
        this.setLastName(lastName);
        this.setSubject(subject);    
    }        
        public String getSubject() {
          return subject;
        }

        public void setSubject(String subject){
        this.subject = subject;
        }  

        @Override
        public String display() {
          return this.getFullName() + "teaches" + this.getSubject();
        }
    }

编译错误

C:\WEBUCATOR\JVA102_2.0.2\DanProject\school>javac teacher.java
teacher.java:2: error: package util does not exist
import util.Displayable;
           ^
teacher.java:4: error: cannot find symbol
  public class Teacher extends Person implements Displayable {
                               ^
  symbol: class Person
teacher.java:4: error: cannot find symbol
  public class Teacher extends Person implements Displayable {
                                                 ^
  symbol: class Displayable
teacher.java:11: error: cannot find symbol
        this.setFirstName(firstName);
            ^
  symbol: method setFirstName(String)
teacher.java:12: error: cannot find symbol
        this.setLastName(lastName);
            ^
  symbol: method setLastName(String)
teacher.java:23: error: method does not override or implement a method from a supertype
        @Override
        ^
teacher.java:25: error: cannot find symbol
          return this.getFullName() + "teaches" + this.getSubject();
                     ^
  symbol: method getFullName()
7 errors

Answer 1

您可能在环境变量中添加了jre路径，或者根本没有添加路径。