调用Scanner向数组中新增元素

Question

我写的代码。运行到所有元素输入完之后就没动静了，要么就抛异常，请大大们帮我看一下，谢谢package Community;import java.util.Scanner;import User.DbStore;public class temp 
{
public static void main(String args[])
{
DbStore abcd = new DbStore();

Scanner scan = new Scanner(System.in);

System.out.println("请输入小区编号：");
String id = scan.next();
System.out.println("请输入小区名称：");
String name = scan.next();
System.out.println("请输入小区经理：");
String manager = scan.next();
System.out.println("请输入所在区域：");
String area = scan.next();
System.out.println("请输入小区状态：");
String statue = scan.next();
System.out.println("请输入渗透率：");
double Permeability = scan.nextDouble();
System.out.println("请输入覆盖用户数：");
int userCount = scan.nextInt();

int last = abcd.getCommArr().length+1;

abcd.getCommArr()[last].setCommId(id);
abcd.getCommArr()[last].setCommName(name);
abcd.getCommArr()[last].setCommManager(manager);
abcd.getCommArr()[last].setCommArea(area);
abcd.getCommArr()[last].setCommStatue(statue);
abcd.getCommArr()[last].setPermeability(Permeability);
abcd.getCommArr()[last].setUserCount(userCount);

System.out.println("新增成功！");
System.out.println("该社区信息如下："+"\n");
System.out.println("小区编号"+"\t\t"+"小区名称"+"\t\t"+"小区经理"+"\t\t"+"区域"+"\t\t"+"小区状态"+"\t\t"+"渗透率"+"\t\t"+"覆盖用户数");
System.out.println("----------------------------------------------------------------------------------------------------------");
System.out.println(abcd.getCommArr()[last].getCommId()+"\t\t"+abcd.getCommArr()[last].getCommName()+"\t\t"+abcd.getCommArr()[last].getCommManager()+"\t\t"+abcd.getCommArr()[last].getCommArea()+"\t\t"+abcd.getCommArr()[last].getCommStatue()+"\t\t"+abcd.getCommArr()[last].getPermeability()+"%"+"\t\t"+abcd.getCommArr()[last].getUserCount());
}
}

Answer 1

想起来你另外一个帖子了，对于你用数组实现的话，是无法直接进行扩容的，你只能重新开辟一个更大的数组将原来的数据拷贝到更大的数组，然后将最新添加的数据放在更大数组尾部效率很低，还是用List合适

Answer 2

DbStore：
package User;import Community.CommunityEntity;public class DbStore 
{
   //声明一个数组变量
    private CommunityEntity[] commArr;    public DbStore() //初始化社区实体数组
    {
     CommunityEntity com1 = new CommunityEntity();
     com1.setCommId("001");
     com1.setCommName("新升新苑");
     com1.setCommManager("大漠");
     com1.setCommArea("高新区");
     com1.setCommStatue("可放装");
     com1.setPermeability(61);
     com1.setUserCount(221);
    
     CommunityEntity com2 = new CommunityEntity();
     com2.setCommId("002");
     com2.setCommName("新盛花园");
     com2.setCommManager("大漠");
     com2.setCommArea("吴中区");
     com2.setCommStatue("可放装");
     com2.setPermeability(62);
     com2.setUserCount(222);
    
     CommunityEntity com3 = new CommunityEntity();
     com3.setCommId("003");
     com3.setCommName("新唯家园");
     com3.setCommManager("大漠");
     com3.setCommArea("工业园区");
     com3.setCommStatue("可放装");
     com3.setPermeability(63);
     com3.setUserCount(223);
    
     CommunityEntity com4 = new CommunityEntity();
     com4.setCommId("004");
     com4.setCommName("蠡东花园");
     com4.setCommManager("大漠");
     com4.setCommArea("相城区");
     com4.setCommStatue("可放装");
     com4.setPermeability(64);
     com4.setUserCount(224);
    
     CommunityEntity com5 = new CommunityEntity();
     com5.setCommId("005");
     com5.setCommName("朱家庄新村");
     com5.setCommManager("大漠");
     com5.setCommArea("金阊区");
     com5.setCommStatue("可放装");
     com5.setPermeability(65);
     com5.setUserCount(225);
  
        setCommArr(new CommunityEntity[]{com1,com2,com3,com4,com5});
    }
public void setCommArr(CommunityEntity[] commArr) 
{
this.commArr = commArr;
}
public CommunityEntity[] getCommArr()
{
return commArr;
}
}
CommunityEntity：package Community;public class CommunityEntity 
{
private String commId;
private String commName;
private String commManager;
private String commArea;
private String commStatue;
private double permeability;
private int userCount;
public String getCommId() 
{
return commId;
}
public void setCommId(String commId)
{
this.commId = commId;
}
public String getCommName() 
{
return commName;
}
public void setCommName(String commName) 
{
this.commName = commName;
}
public String getCommManager() 
{
return commManager;
}
public void setCommManager(String commManager)
{
this.commManager = commManager;
}
public String getCommArea()
{
return commArea;
}
public void setCommArea(String commArea)
{
this.commArea = commArea;
}
public String getCommStatue() 
{
return commStatue;
}
public void setCommStatue(String commStatue) 
{
this.commStatue = commStatue;
}
public double getPermeability() 
{
return permeability;
}
public void setPermeability(double permeability)
{
this.permeability = permeability;
}
public int getUserCount() 
{
return userCount;
}
public void setUserCount(int userCount) 
{
this.userCount = userCount;
}
}
类们都在这了。求帮助

Answer 3

我只是学习一下。list什么的，没资料学。。

Answer 4

新增元素不能这么写的...
public  static int[] add(int[] arr,int b)
{
int[] c = new int[arr.length+1];
for(int i=0;i<arr.length;i++)
{
c[i]=arr[i];
}
c[arr.length] = b;
return c;
}
每次增加一个元素，新建一个数组赋值，返回值就是你要的
或者你一开始就新建一个足够大的数组，然后设置一个size标量表示有多少个元素，添加的时候判断size++比数组length小就放入那样的

Answer 5

我用java里面的List重新给你写了一个实现，还有提醒你看看Java编码规范，类名首字母一定大写，包的首字母不大写，还有局部变量的名称首字母也不大写，三个类放在了一个包下面package csdn.p31;public class CommunityEntity
{
    private String commId;
    private String commName;
    private String commManager;
    private String commArea;
    private String commStatue;
    private double permeability;
    private int userCount;    public CommunityEntity(){}    @Override
    public String toString() {
        return "CommunityEntity{" +
                "commId='" + commId + '\'' +
                ", commName='" + commName + '\'' +
                ", commManager='" + commManager + '\'' +
                ", commArea='" + commArea + '\'' +
                ", commStatue='" + commStatue + '\'' +
                ", permeability=" + permeability +
                ", userCount=" + userCount +
                '}';
    }    public String getCommId()
    {
        return commId;
    }
    public void setCommId(String commId)
    {
        this.commId = commId;
    }
    public String getCommName()
    {
        return commName;
    }
    public void setCommName(String commName)
    {
        this.commName = commName;
    }
    public String getCommManager()
    {
        return commManager;
    }
    public void setCommManager(String commManager)
    {
        this.commManager = commManager;
    }
    public String getCommArea()
    {
        return commArea;
    }
    public void setCommArea(String commArea)
    {
        this.commArea = commArea;
    }
    public String getCommStatue()
    {
        return commStatue;
    }
    public void setCommStatue(String commStatue)
    {
        this.commStatue = commStatue;
    }
    public double getPermeability()
    {
        return permeability;
    }
    public void setPermeability(double permeability)
    {
        this.permeability = permeability;
    }
    public int getUserCount()
    {
        return userCount;
    }
    public void setUserCount(int userCount)
    {
        this.userCount = userCount;
    }
}package csdn.p31;import java.util.List;
import java.util.ArrayList;public class DbStore
{
    public List<CommunityEntity> getCommList() {
        return commList;
    }//声明一个数组变量    public void setCommList(List<CommunityEntity> commList) {
        this.commList = commList;
    }    private List<CommunityEntity> commList=new ArrayList<CommunityEntity>();    public DbStore() //初始化社区实体数组
    {
       
        CommunityEntity com1 = new CommunityEntity();
        com1.setCommId("001");
        com1.setCommName("新升新苑");
        com1.setCommManager("大漠");
        com1.setCommArea("高新区");
        com1.setCommStatue("可放装");
        com1.setPermeability(61);
        com1.setUserCount(221);        CommunityEntity com2 = new CommunityEntity();
        com2.setCommId("002");
        com2.setCommName("新盛花园");
        com2.setCommManager("大漠");
        com2.setCommArea("吴中区");
        com2.setCommStatue("可放装");
        com2.setPermeability(62);
        com2.setUserCount(222);        CommunityEntity com3 = new CommunityEntity();
        com3.setCommId("003");
        com3.setCommName("新唯家园");
        com3.setCommManager("大漠");
        com3.setCommArea("工业园区");
        com3.setCommStatue("可放装");
        com3.setPermeability(63);
        com3.setUserCount(223);        CommunityEntity com4 = new CommunityEntity();
        com4.setCommId("004");
        com4.setCommName("蠡东花园");
        com4.setCommManager("大漠");
        com4.setCommArea("相城区");
        com4.setCommStatue("可放装");
        com4.setPermeability(64);
        com4.setUserCount(224);        CommunityEntity com5 = new CommunityEntity();
        com5.setCommId("005");
        com5.setCommName("朱家庄新村");
        com5.setCommManager("大漠");
        com5.setCommArea("金阊区");
        com5.setCommStatue("可放装");
        com5.setPermeability(65);
        com5.setUserCount(225);//        setCommArr(new CommunityEntity[]{com1,com2,com3,com4,com5});
        commList.add(com1);
        commList.add(com2);
        commList.add(com3);
        commList.add(com4);
        commList.add(com5);    }}package csdn.p31;import java.util.Scanner;
import java.util.List;public class Temp 
{
    public static void main(String args[])
    {
        DbStore store= new DbStore();        Scanner scan = new Scanner(System.in);        System.out.println("请输入小区编号：");
        String id = scan.next();
        System.out.println("请输入小区名称：");
        String name = scan.next();
        System.out.println("请输入小区经理：");
        String manager = scan.next();
        System.out.println("请输入所在区域：");
        String area = scan.next();
        System.out.println("请输入小区状态：");
        String statue = scan.next();
        System.out.println("请输入渗透率：");
        double permeability = scan.nextDouble();
        System.out.println("请输入覆盖用户数：");
        int userCount = scan.nextInt();        List<CommunityEntity> list=store.getCommList();
        CommunityEntity ce=new CommunityEntity();
        ce.setCommId(id);
        ce.setCommName(name);
        ce.setCommManager(manager);
        ce.setCommArea(area);
        ce.setCommStatue(statue);
        ce.setPermeability(permeability);
        ce.setUserCount(userCount);
        list.add(ce);        System.out.println("新增成功！");
        System.out.println("该社区信息如下："+"\n");
        System.out.println(ce);
//        System.out.println("小区编号"+"\t\t"+"小区名称"+"\t\t"+"小区经理"+"\t\t"+"区域"+"\t\t"+"小区状态"+"\t\t"+"渗透率"+"\t\t"+"覆盖用户数");
//        System.out.println("----------------------------------------------------------------------------------------------------------");
        for(CommunityEntity c:list){
            System.out.println("info:"+c);
        }
        
    }
}

Answer 6

新增部分已经做完了，改了一下，很好用。我再试试删除部分也用list，感谢你，熊猫哥