How to create an arraylist class that can store multiple data type objects in java

StackOverflow https://stackoverflow.com/questions/23395263

  •  12-07-2023
  •  | 
  •  

質問

I am using a JDBC query that returns output as following:

Name       Id
A          1
B          2

Then I am trying to generate an arrylist based on the query result using the following java class:

private class GetCompanyInfo implements Work {
    ArrayList<CompanyRelatedInfo> companyRelatedDataList = new ArrayList<CompanyRelatedInfo>();
    private String queryString;

    @Override
    public void execute(Connection connection) throws SQLException {        
        PreparedStatement ps = connection.prepareStatement(queryString);
        ResultSet rs = ps.executeQuery();
        CompanyRelatedInfo ci = new CompanyRelatedInfo();       
        while(rs.next())
        {   
            String name = rs.getString("name");
            Long id = rs.getLong("id");

            ci.setName(name);
            ci.setId(id);
            companyRelatedDataList.add(ci);
        }   
        rs.close();
        ps.close();
    }
}

But the problem is the arraylist returns results as following:

Name       Id
B          2
B          2

How can I generate the arraylist as following:

Name       Id
A          1
B          2
役に立ちましたか?

解決

Create a new instance of CompanyRelatedInfo instead of using the same. You are just modifying one and the same object for all rows and put it multiple times into the list. So try and use the following:

while(rs.next()) {   
  CompanyRelatedInfo ci = new CompanyRelatedInfo();       
  ...
ライセンス: CC-BY-SA帰属
所属していません StackOverflow
scroll top