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在 ArrayList 内的对象类中放置值时出错

[英]Error in placing values in an object class inside an ArrayList

我正在尝试创建一个表(2d),其中每个单元格都包含一个值和键(为此创建了一个对象),但是我无法从ArrayList将值放置到对象中。

不兼容的类型: String不能转换为int

public static void Con(){
ArrayList<Content> arrList1 = new ArrayList<Content>();
ArrayList<ArrayList> arrList2 = new ArrayList<ArrayList>();

//Content yeah = new Content("asdfas","asdfasdf");
for(Content a: arrList1)
//arrList1.add(Content a = new Content("asdf","fasd"));
arrList1.add("oh","yeah");
//arrList1.ge

}

这是对象类

public class Content extends Object{
    private String key;
    private String value;   
    private String keyVal;

    public Content (String key, String value) {

        this.key = key;
        this.value = value;
    }

    public String getKey() {

        return key; 
    }

    public String getValue() {

        return value;   
    }

    public String getKeyValue(){
        return key+value;
    }

    public void display(){      
        System.out.println(this.key+","+this.value);
    }

}

我已经想通了。 我用了:

arrList1.add(new Content("9","9"));

抱歉,添麻烦了

ArrayList<object> ArrayList 内部<anotherobject>在 class 内部,在 RecyclerView 中发送数据<div id="text_translate"><p>对不起 forms 我是法语的英语</p><p>我有 3 个 class,其中 2 个有 ArrayList。 不幸的是,我的 object 和 2 ArrayList 无法工作。 我在 Android Studio 中使用 Java</p><p> 第一个 class:面板:</p><pre> public class Panel { public String nameUser; public String street; public String panelId; public ArrayList&lt;Block&gt; listBlock; public Panel(String nameUser, String street, String panelId, ArrayList&lt;Block&gt; listBlock) { this.nameUser = nameUser; this.street = street; this.panelId = panelId; this.listBlock = listBlock; } public String getNameUser() { return nameUser; } public void setNameUser(String nameUser) { this.nameUser = nameUser; } public String getStreet() { return street; } public void setStreet(String street) { this.street = street; } public String getPanelId() { return panelId; } public void setPanelId(String panelId) { this.panelId = panelId; } public ArrayList&lt;Block&gt; getListBlock() { return listBlock; } public void setListBlock(ArrayList&lt;Block&gt; listBlock) { this.listBlock = listBlock; } }</pre><p> 第二个 class: 块:</p><pre> import java.util.ArrayList; public class Block { public String nameLine; public ArrayList&lt;Breaker&gt; listBreaker; public String getNameLine() { return nameLine; } public void setNameLine(String nameLine) { this.nameLine = nameLine; } public ArrayList&lt;Breaker&gt; getListBreaker() { return listBreaker; } public void setListBreaker(ArrayList&lt;Breaker&gt; listBreaker) { this.listBreaker = listBreaker; } public Block(String nameLine, ArrayList&lt;Breaker&gt; listBreaker) { this.nameLine = nameLine; this.listBreaker = listBreaker; } }</pre><p> 第三课(最后一课):断路器:</p><pre> public class Breaker { public String name; public String utilisation; public Breaker(String name, String utilisation) { this.name = name; this.utilisation = utilisation; } public String getNom() { return name; } public void setNom(String nom) { this.name = name; } public String getUtilisation() { return utilisation; } public void setUtilisation(String utilisation) { this.utilisation = utilisation; } }</pre><p> 我的主要活动:</p><pre> public class Activity_PanelHome extends AppCompatActivity { private ArrayList&lt;Panel&gt; listPanel; private ArrayList&lt;Block&gt; listBlock; private ArrayList&lt;Breaker&gt; listBreaker; private RecyclerView recyclerView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_panelhome); recyclerView = findViewById(R.id.recyclerViewHomePage); ArrayList&lt;Panel&gt; listPanel = new ArrayList&lt;&gt;(); List&lt;Block&gt; listBlock = new ArrayList&lt;&gt;(); List&lt;Breaker&gt; listBreaker = new ArrayList&lt;Breaker&gt;(); setUserInfo(); setAdapter(); } private void setAdapter() { RecyclerAdapter adapter = new RecyclerAdapter(listPanel); RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getApplicationContext()); recyclerView.setLayoutManager(layoutManager); recyclerView.setItemAnimator(new DefaultItemAnimator()); recyclerView.setAdapter(adapter); } private void setUserInfo() { listBreaker.add(new Breaker("BreakerName","BreakerUtilisation")); listBlock.add(new Block("BlockName",listBreaker)); listPanel.add(new Panel("PanelUserName","PanelStreet","PanelId",listBlock)); } }</pre><p> 我得到的错误</p><pre>Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.util.ArrayList.add(java.lang.Object)' on a null object reference at com.example.application.Activity.Activity_PanelHome.setUserInfo(Activity_PanelHome.java:48) at com.example.application.Activity.Activity_PanelHome.onCreate(Activity_PanelHome.java:36)</pre><p> Ligne 36:(这是方法)</p><pre> setUserInfo();</pre><p> 利格 48:</p><pre> listBreaker.add(new Breaker("BreakerName","BreakerUtilisation"));</pre><p> 预先感谢您的帮助:)</p></div></anotherobject></object>

[英]ArrayList<object> inside ArrayList<anotherObject> inside a class, to send the data in RecyclerView

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相关问题 将对象保存在另一个类的arraylist内 创建下一个对象并将其放置在ArrayList中 ArrayList<object> ArrayList 内部<anotherobject>在 class 内部,在 RecyclerView 中发送数据<div id="text_translate"><p>对不起 forms 我是法语的英语</p><p>我有 3 个 class,其中 2 个有 ArrayList。 不幸的是,我的 object 和 2 ArrayList 无法工作。 我在 Android Studio 中使用 Java</p><p> 第一个 class:面板:</p><pre> public class Panel { public String nameUser; public String street; public String panelId; public ArrayList&lt;Block&gt; listBlock; public Panel(String nameUser, String street, String panelId, ArrayList&lt;Block&gt; listBlock) { this.nameUser = nameUser; this.street = street; this.panelId = panelId; this.listBlock = listBlock; } public String getNameUser() { return nameUser; } public void setNameUser(String nameUser) { this.nameUser = nameUser; } public String getStreet() { return street; } public void setStreet(String street) { this.street = street; } public String getPanelId() { return panelId; } public void setPanelId(String panelId) { this.panelId = panelId; } public ArrayList&lt;Block&gt; getListBlock() { return listBlock; } public void setListBlock(ArrayList&lt;Block&gt; listBlock) { this.listBlock = listBlock; } }</pre><p> 第二个 class: 块:</p><pre> import java.util.ArrayList; public class Block { public String nameLine; public ArrayList&lt;Breaker&gt; listBreaker; public String getNameLine() { return nameLine; } public void setNameLine(String nameLine) { this.nameLine = nameLine; } public ArrayList&lt;Breaker&gt; getListBreaker() { return listBreaker; } public void setListBreaker(ArrayList&lt;Breaker&gt; listBreaker) { this.listBreaker = listBreaker; } public Block(String nameLine, ArrayList&lt;Breaker&gt; listBreaker) { this.nameLine = nameLine; this.listBreaker = listBreaker; } }</pre><p> 第三课(最后一课):断路器:</p><pre> public class Breaker { public String name; public String utilisation; public Breaker(String name, String utilisation) { this.name = name; this.utilisation = utilisation; } public String getNom() { return name; } public void setNom(String nom) { this.name = name; } public String getUtilisation() { return utilisation; } public void setUtilisation(String utilisation) { this.utilisation = utilisation; } }</pre><p> 我的主要活动:</p><pre> public class Activity_PanelHome extends AppCompatActivity { private ArrayList&lt;Panel&gt; listPanel; private ArrayList&lt;Block&gt; listBlock; private ArrayList&lt;Breaker&gt; listBreaker; private RecyclerView recyclerView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_panelhome); recyclerView = findViewById(R.id.recyclerViewHomePage); ArrayList&lt;Panel&gt; listPanel = new ArrayList&lt;&gt;(); List&lt;Block&gt; listBlock = new ArrayList&lt;&gt;(); List&lt;Breaker&gt; listBreaker = new ArrayList&lt;Breaker&gt;(); setUserInfo(); setAdapter(); } private void setAdapter() { RecyclerAdapter adapter = new RecyclerAdapter(listPanel); RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getApplicationContext()); recyclerView.setLayoutManager(layoutManager); recyclerView.setItemAnimator(new DefaultItemAnimator()); recyclerView.setAdapter(adapter); } private void setUserInfo() { listBreaker.add(new Breaker("BreakerName","BreakerUtilisation")); listBlock.add(new Block("BlockName",listBreaker)); listPanel.add(new Panel("PanelUserName","PanelStreet","PanelId",listBlock)); } }</pre><p> 我得到的错误</p><pre>Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean java.util.ArrayList.add(java.lang.Object)' on a null object reference at com.example.application.Activity.Activity_PanelHome.setUserInfo(Activity_PanelHome.java:48) at com.example.application.Activity.Activity_PanelHome.onCreate(Activity_PanelHome.java:36)</pre><p> Ligne 36:(这是方法)</p><pre> setUserInfo();</pre><p> 利格 48:</p><pre> listBreaker.add(new Breaker("BreakerName","BreakerUtilisation"));</pre><p> 预先感谢您的帮助:)</p></div></anotherobject></object> 如何在java中的类中创建一个带有对象的Arraylist 如何获取ArrayList内部对象的属性和值? 从另一个类修改ArrayList对象的值 该对象内的对象的数组列表 如何打印java中arraylist内的pojo对象的值? 在Java的ArrayList中的类对象中保留一个独立的ID计数器 如何使用一对 object ZA2F2ED4F8EBC2CBB4C21A29DC40AB6 将 HashMap 中的值复制到 ArrayList
 
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