用反射实现通用Dao

public class MySession {
	/**
	 * 用反射实现的查找
	 */
	public Object find(Class clazz,Object id){
		try {
			//通过反射获取clazz的类名
			QueryRunner query = new QueryRunner();
			String className = clazz.getName();
			String[] split = className.split("\\.");
			String tableName = split[split.length - 1];
			String sql = "select * from " + tableName + " where id=?";
			//Object c =  query.query(sql, new BeanHandler(clazz), new Object[] { id });
			System.out.println(sql);
			return null;
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}
	/*
	 * 实现删除
	 */
	public  void delete(Class clazz,Object id){
		try {
			QueryRunner runner = new QueryRunner();
			String className = clazz.getName();
			String[] split = className.split("\\.");
			String tableName = split[split.length - 1];
			String sql = "delete from " + tableName + "where id=?";
			//runner.update(sql, new Object[] { id });
		} catch (Exception e) {
			
		}
	}
	/**
	 * 实现增加
	 */
	public void add(Class clazz){
		//首先获得表名
		QueryRunner runner = new QueryRunner();
		String className = clazz.getName();
		String[] split = className.split("\\.");
		String tableName = split[split.length - 1];
		//通过反射获得字段
		Field[] fields = clazz.getDeclaredFields();
		StringBuilder sb = new StringBuilder("insert into  ");
		sb.append(tableName+" (");
		for(Field f:fields){
			sb.append(f.getName()+",");
		}
		sb.deleteCharAt(sb.length()-1);
		sb.append(")");
		
		sb.append(" values(");
		for(int i=0;i<fields.length;i++){
			sb.append("?,");
		}
		sb.deleteCharAt(sb.length()-1);
		sb.append(")");
		String sql = sb.toString();
		System.out.println("--------add---------\n"+sql);
	}
	/*
	 * 修改同类增加
	 */

 

评论

2 楼 shamusoft 2011-05-27  

try {
Class clazz = bean.getClass();
String className = clazz.getName();
String[] split = className.split("\\.");
String tableName = split[split.length - 1];
Field[] fields = clazz.getDeclaredFields();
QueryRunner runner = new QueryRunner(JbcUtils.getDataResource());
StringBuilder sql = new StringBuilder("insert into ");
sql.append(tableName + " (");
for (Field f : fields) {
sql.append(f + ",");
}
sql.deleteCharAt(sql.length() - 1);
sql.append(" ) values (");
for (Field f : fields) {
sql.append("?,");
}
sql.deleteCharAt(sql.length() - 1);
sql.append(" ) where id=?");
Object params[]= new Object[fields.length];
for(int i=0;i<fields.length;i++){
String value = BeanUtils.getProperty(bean,fields[i].getName());
params[i]=value;
}
int count = runner.update(sql.toString(),params);
if(count>0)return true;
return false;

} catch (Exception e) {
throw new DaoException();
}

1 楼 shamusoft 2011-05-27  

Object[] params = new Object[fields.length];
for(int i=0; i<fields.length; i++) {
String value = BeanUtils.getProperty(bean, fields[i].getName());
System.out.println(value);
params[i] = value;
}