HOw将其转换为通用形式

Question

我写了下面的函数，我想把它写成通用的所有java bean，它将返回我传递的bean名称类型的列表。

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; 
    } 

请帮忙。

Answer 1

做一些假设，这里有一个例子：

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; 
    } 
} 

然后T可能是_ItemCreditQuality bean类，并且你会这样称呼它：

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