java，获取set方法 [英] java, get set methods
问题描述
这个问题之前已经被问过了，但即使在阅读后：
Java Get / Set方法返回null
更多我还是不明白如何解决我的问题。
使用另一个类的get方法访问类中的变量时，我收到值为null。
我如何接收我的正确值而不是null？
这是我尝试从我的变量中获取变量的类（并非包含所有变量）。
public class RLS_character_panel extends javax.swing.JPanel implements ActionListener，ItemListener {
private String name1 = 你好;
public String getName1（）{
return name1;
}
public void setName1（String name1）{
this.name1 = name1;
}
}
这是我尝试获取值TO的类。该类扩展了JFrame，以便我可以添加一个显示变量的JPanel。 （JPanel是另一个类，名为：RLS_strid_panel，它被添加到这个帧上）。
public class RLS_strid_java extends JFrame {
RLS_character_panel test = new RLS_character_panel（）;
String name1 = test.getName1（）;
RLS_strid_panel p = new RLS_strid_panel（namn1）;
//构造函数
public RLS_strid_java（字符串标题）{
super（titel）;
this.setSize（1000，772）;
this.setVisible（true）;
this.setResizable（false）;
this.add（p）;
$ / code $ / pre
$ hr
Jpanel Displays null。
解决方案为了理解get和set，它们都与变量在不同类之间传递的方式有关。
get方法用于从类中获取或检索特定的变量值。
设置值用于存储变量。
get和set的整点是检索并存储相应的数据值。
我在这个旧项目中做了什么，我有一个User类，其中包含我在Server类中使用的get和set方法。
User类的get方法：
public int getuserID ）
{
//获取userID变量实例
返回userID;
}
public String getfirstName（）
{
//获取firstName变量实例
返回firstName;
}
public String getlastName（）
{
//获取lastName变量实例
返回lastName;
}
public int getage（）
{
//获取年龄变量实例
返回年龄;
}
public void setuserID（int userID）
{
//设置userID变量值
this.userID = userID;
}
public void setfirstName（String firstName）
{
//设置firstName变量文本
this.firstName = firstName;
}
public void setlastName（String lastName）
{
//设置lastName变量文本
this.lastName = lastName;
}
public void setage（int age）
{
//设置年龄变量值
this.age = age;
然后在 run（）方法在我的Server类中，如下所示：
//创建用户对象
User use = new User（userID，firstName，lastName，age）;
//用于设置用户对象的Mutator方法
use.setuserID（userID）;
use.setlastName（lastName）;
use.setfirstName（firstName）;
use.setage（age）;
This question has been asked before, but even after reading:
Java Get/Set method returns null
And more I still don't understand how to solve my problem.
When accessing variables in a class using get methods from another class I receive the value null.
How do I recieve my correct values instead of null?
This is the class where I try to get my variables FROM (not everything included).
public class RLS_character_panel extends javax.swing.JPanel implements ActionListener, ItemListener {
private String name1 = "hello";
public String getName1() {
return name1;
}
public void setName1(String name1) {
this.name1 = name1;
}
}
This is the class where i try to get the values TO. This class extends JFrame so that I can add a JPanel which displays the variable. (the JPanel is yet another class called: RLS_strid_panel , which is added upon this frame).
public class RLS_strid_java extends JFrame {
RLS_character_panel test = new RLS_character_panel();
String name1 = test.getName1();
RLS_strid_panel p = new RLS_strid_panel(namn1);
// constructor
public RLS_strid_java(String titel) {
super(titel);
this.setSize(1000, 772);
this.setVisible(true);
this.setResizable(false);
this.add(p);
}
}
the Jpanel Displays null.
解决方案 To understand get and set, it's all related to how variables are passed between different classes.
The get method is used to obtain or retrieve a particular variable value from a class.
A set value is used to store the variables.
The whole point of the get and set is to retrieve and store the data values accordingly.
What I did in this old project was I had a User class with my get and set methods that I used in my Server class.
The User class's get set methods:
public int getuserID()
{
//getting the userID variable instance
return userID;
}
public String getfirstName()
{
//getting the firstName variable instance
return firstName;
}
public String getlastName()
{
//getting the lastName variable instance
return lastName;
}
public int getage()
{
//getting the age variable instance
return age;
}
public void setuserID(int userID)
{
//setting the userID variable value
this.userID = userID;
}
public void setfirstName(String firstName)
{
//setting the firstName variable text
this.firstName = firstName;
}
public void setlastName(String lastName)
{
//setting the lastName variable text
this.lastName = lastName;
}
public void setage(int age)
{
//setting the age variable value
this.age = age;
}
}
Then this was implemented in the run() method in my Server class as follows:
//creates user object
User use = new User(userID, firstName, lastName, age);
//Mutator methods to set user objects
use.setuserID(userID);
use.setlastName(lastName);
use.setfirstName(firstName);
use.setage(age);
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