如何使用Javac将类导入java程序?
导言 我正在使用终端和Javac来编译和运行我的java程序。个别项目运作良好。然而,当我想将一个类导入我的主Java程序时,我会收到错误 源代码-我的类(Name.java) Main-NameDemo.java如何使用Javac将类导入java程序?,java,linux,javac,Java,Linux,Javac,导言 我正在使用终端和Javac来编译和运行我的java程序。个别项目运作良好。然而,当我想将一个类导入我的主Java程序时,我会收到错误 源代码-我的类(Name.java) Main-NameDemo.java public class Name { //Fields private String firstName; private String familyName; //Constructors public Name() { firstName = ""; fa
public class Name {
//Fields
private String firstName;
private String familyName;
//Constructors
public Name() {
firstName = "";
familyName = "";
}
public Name(String firstName, String familyName) {
this.firstName = firstName;
this.familyName = familyName;
}
//Methods
public void setFirstName(String firstName) {
this.firstName = firstName;
}
public void setFamilyName(String familyName) {
this.familyName = familyName;
}
public String getFirstName() {
return firstName;
}
public String getFamilyName() {
return familyName;
}
public String getFullName() {
if (firstName.equals("") && familyName.equals("")) {
return "";
} else {
return firstName + " " + familyName;
}
}
@Override
public String toString() {
return "Name:[firstName=" + firstName + ", familyName=" + familyName + "]";
}
}
import Name;
public class NameDemo {
public static void main(String[] args) {
/*
* See below evidence of how arrays can store elements of a custom reference
* type that you create (Name in this case), as well as both existing
* reference types (e.g. String) or primitive types (e.g. int), that you have
* previously worked with.
*/
//declare array to hold four Name objects
Name[] friends = new Name[4];
//create Name object and assign reference into array
Name joe = new Name("Joe", "Bloggs");
friends[0] = joe;
//create Name objects and assign reference directly into array
friends[1] = new Name("Fred", "Perry");
friends[2] = new Name("Diti", "Hammond");
friends[3] = new Name("Bulsar", "Raymond");
//loop through each element
for(int i = 0; i < friends.length; i++) {
//use accessor method to output full name of each
System.out.println(friends[i].getFullName());
}
//declare boolean used as a flag
boolean exists = false;
//loop through each Name object using a for-each loop (you will see more on this when we cover ArrayLists)
for (Name nm : friends) {
//check family name
if (nm.getFamilyName().equals("Smith")) {
exists = true;
}
}
//output result of search
if (exists) {
System.out.println("There is a person with family name of Smith");
} else {
System.out.println("There is not a person with family name of Smith");
}
//Checking output of toString
System.out.println("\n" + joe.toString());
}
}
为什么会发生这种情况,我应该编译这个类吗?或者类是否需要以.class或.java结尾?这也是导入的语法问题吗 所以:
import packagename.classname代码>而您只提供了classname
编译为字节码的类需要有扩展名。Class,而您编写的源代码中的类需要有扩展名。java尝试使用以下命令。在文件所在的同一目录中
javac*.java不能从默认包导入类。好消息是:您不需要这样做,因为两个类都驻留在那里。只需省略
import
语句。这对导入问题没有帮助。
javac Name.java
javac NameDemo.java
NameDemo.java:4: error: '.' expected
import Name;
^
NameDemo.java:4: error: ';' expected
import Name;
^
2 errors