Table t = (Table)c.getAnnotation(Table.class);

String tableName = t.value();

sb.append("select*from").append(tableName).append("where 1=1");

//3.遍歷所有的字段

Field[] fArray = c.getDeclaredFields();

for (Field field : fArray) {

//4.處理每個(gè)字段對(duì)應(yīng)的值

//4.1獲取字段的名

boolean fExists = field.isAnnotationPresent(Column.class);

if(!fExists) {

continue;

}

Column column = field.getAnnotation(Column.class);

為什么Table t = (Table)c.getAnnotation(Table.class)要強(qiáng)轉(zhuǎn)成Table，而Column column = field.getAnnotation(Column.class)就不用強(qiáng)轉(zhuǎn)為Column?