HOw將其轉換爲通用形式

Question

我寫了下面的函數，我想把它寫成通用的所有java bean，它將返回我傳遞的bean名稱類型的列表。

public List<_ItemCreditQuality> getCrediQuality(String type,String def) throws SQLException{ 

     sql = ""; 

     stmt = con.createStatement(); 

     rs = stmt.executeQuery(sql); 

     QueryRunner run = new QueryRunner(); 
     ResultSetHandler<List<_ItemCreditQuality>> h = new BeanListHandler<_ItemCreditQuality>(_ItemCreditQuality.class); 
     creditQualityList = run.query(con, sql, h); 

     return creditQualityList; 
    } 

請幫忙。

Answer 1

做一些假設，這裏有一個例子：

public <T> List<T> getCreditQuality(Class<T> beanClass) throws SQLException { 
    String sql = "SELECT * FROM " + beanClass.getSimpleName(); 
    try (
     Statement stmt = this.con.createStatement(); 
     ResultSet rs = stmt.executeQuery(sql); 
    ) { 
     QueryRunner run = new QueryRunner(); 
     ResultSetHandler<List<T>> h = new BeanListHandler<T>(beanClass); 
     List<T> creditQualityList = run.query(this.con, sql, h); 
     return creditQualityList; 
    } 
} 

然後T可能是_ItemCreditQuality bean類，並且你會這樣稱呼它：

List<_ItemCreditQuality> list = getCreditQuality(_ItemCreditQuality.class);