不确定条件查询

@Test
	public void query1() throws Exception{
		QueryRunner run = new QueryRunner(DataSourceUtils.getDatasSource());
		Contact c = new Contact();
		//c.setId("C001");
		c.setName("王'");
		c.setSex("1");
		c.setTel("123");
		c.setAddr("中国");
		c.setAge(55);
		String sql = "select * from contacts where 1=1 ";
		List<Object> params = new ArrayList<Object>();
		if(c.getId()!=null){
			sql+=" and id=?";
			params.add(c.getId());
		}
		if(c.getSex()!=null){
			sql = sql+" and sex=?";
			params.add(c.getSex());
		}
		if(c.getName()!=null){
			sql+=" and name like ?";
			params.add("%"+c.getName()+"%");
		}
		if(c.getAddr()!=null){
			sql+=" and addr like ?";
			params.add("%"+c.getAddr()+"%");
		}
		if(c.getTel()!=null){
			sql+=" and tel like ?";
			params.add("%"+c.getTel()+"%");
		}
		if(c.getAge()!=null){
			sql+=" and age=?";
			params.add(c.getAge());
		}
		System.err.println(">>>>>>:"+sql);
		System.err.println(params);
		List<Contact> cs = run.query(sql,
					  new BeanListHandler<Contact>(Contact.class),
					  params.toArray());
		for(Contact cc:cs){
			System.err.println(cc);
		}
		
		
	}