JDK+JDBC+MySQL实例及注意事项

/**
	 *  Using reflection to storage the result from database into Bean class.
	 *  
	 */
	public static List<Object> resultSetToList(ResultSet rs, Class<?> cls) {  	      
        Method[] methods = cls.getDeclaredMethods();  
        int methodLength = methods.length;
        
        int index;
        Map<String, Integer> map = new HashMap<String, Integer>();
        // record all methods name in a HashMap, for quickly locate.
        for (index = 0; index < methodLength; index++) {
        	map.put(methods[index].getName().toLowerCase(), index);
        }  
         
        ResultSetMetaData meta = null;
        Object obj = null;  
        List<Object> list = new ArrayList<Object>(); 
        
        try {
        	meta = rs.getMetaData();
		    int colCount = meta.getColumnCount();
			while (rs.next()) {  
			    obj = cls.newInstance(); 
			    
			    for (int i = 1; i <= colCount; i++) {  
			        String colName = meta.getColumnName(i);  
			        String setMethodName = "set" + colName;    
//			        System.out.println(setMethodName);
			        int j = map.get(setMethodName.toLowerCase()); //get index of method array
			        setMethodName = methods[j].getName();
			        
			        Object value = rs.getObject(colName);   
	                if(value == null){  
	                    continue;  
	                }  
	               
	                try {    
	                    Method setMethod = obj.getClass().getMethod(setMethodName, value.getClass());   
	                    setMethod.invoke(obj, value);
	                } catch (Exception e) {     
	                	System.out.println(setMethodName + " exception");
	                   e.printStackTrace();  
	                }   			       
			        
			    }  
			    list.add(obj);  
			}
		} catch (InstantiationException | IllegalAccessException | SQLException e) {
			e.printStackTrace();
		}  
        
        return list;        
}