basedaoimp.java

Java开发的权限管理的例子

package org.artemis.right.jdbc.dao;

import java.util.List;

import org.artemis.right.jdbc.util.SQLUtils;
import org.artemis.right.jdbc.vo.UserVO;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.ClassPathResource;
import org.springframework.jdbc.core.JdbcTemplate;


public class BaseDAOImp implements BaseDAO {
	private JdbcTemplate jdbcTemplate;
	private String tableName;
	private Class objectClass;
	private String keyColumn;
	
	public void setKeyColumn(String keyColumn) {
		this.keyColumn = keyColumn;
	}

	public void setJdbcTemplate(JdbcTemplate jdbcTemplate) {
		this.jdbcTemplate = jdbcTemplate;
	}

	public void setObjectClass(Class objectClass) {
		this.objectClass = objectClass;
	}

	public void setTableName(String tableName) {
		this.tableName = tableName;
	}

	public int delete(Object id) {
        String sql = "delete from " + tableName + " where "+keyColumn+"=?";
        return jdbcTemplate.update(sql, new Object[]{id});
	}

	public List findAll() {
        String sql = "select * from " + tableName;
        return jdbcTemplate.query(sql, new DAORowMapper(objectClass));
	}

	public Object findByID(Object id) {
        String sql = "select * from " + tableName + " where " + keyColumn + "=?";
        return jdbcTemplate.queryForObject(sql, new Object[]{id}, new DAORowMapper(objectClass));
	}

	/*
	 * 这里用的Database的主键自增策略，如果想自己实现可以去看看Hibernate的主键生成方法
	 * 其实简单一点可以在server起来的时候定义一个存放主键的Map,然后让这些主键值递增就可以了，
	 * 只是要注意一下并发问题
	 */
	public int insert(Object obj) {
		Object[] sqlAndParams = SQLUtils.generateInsert(obj, tableName);
		return jdbcTemplate.update((String)sqlAndParams[0], (Object[])sqlAndParams[1]);
	}

	public int update(Object obj) {
		Object[] sqlAndParams = SQLUtils.generateUpdate(obj, tableName, keyColumn);
		return jdbcTemplate.update((String)sqlAndParams[0], (Object[])sqlAndParams[1]);
	}
		
	public static void main(String[] args){
        // init factory:
        XmlBeanFactory factory = new XmlBeanFactory(new ClassPathResource("applicationContext.xml"));

        BaseDAO userDAO = (BaseDAO)factory.getBean("userDAO");
        // find all
        List list = userDAO.findAll();
        System.out.println("user count: "+list.size());
        // find by id
        UserVO userVO = (UserVO)userDAO.findByID(new Integer(2));
        System.out.println("Ginger's Email: "+userVO.getEmail());
        // insert
        userVO = new UserVO();
        userVO.setName("tester1");
        userVO.setEmail("[e-mail]");
        int insertResult = userDAO.insert(userVO);
        System.out.println("insert returned: "+insertResult);
        //update
        userVO = new UserVO();
        userVO.setId(new Integer(3));
        userVO.setName("tester33");
        userVO.setEmail("[e-mail]");
        int updateResult = userDAO.update(userVO);
        System.out.println("update returned: "+updateResult);
        //delete
        int deleteResult = userDAO.delete(new Integer(4));
        System.out.println("delete returned: "+deleteResult);
	}
}