根据Common BeanUtils的用户指南学习了很多有用的工具类.
参考:http://commons.apache.org/beanutils/apidocs/org/apache/commons/beanutils/package-summary.html#package_description
1. 属性的存取
简单式:
PropertyUtils.getSimpleProperty(Object bean, String name)
PropertyUtils.setSimpleProperty(Object bean, String name, Object value)
索引式:
PropertyUtils.getIndexedProperty(Object bean, String name)
PropertyUtils.getIndexedProperty(Object bean, String name, int index)
PropertyUtils.setIndexedProperty(Object bean, String name, Object value)
PropertyUtils.setIndexedProperty(Object bean, String name, int index, Object value)
Map式:
PropertyUtils.getMappedProperty(Object bean, String name)
PropertyUtils.getMappedProperty(Object bean, String name, String key)
PropertyUtils.setMappedProperty(Object bean, String name, Object value)
PropertyUtils.setMappedProperty(Object bean, String name, String key, Object value)
嵌套式:
PropertyUtils.getNestedProperty(Object bean, String name)
PropertyUtils.setNestedProperty(Object bean, String name, Object value)
通用式:
PropertyUtils.getProperty(Object bean, String name)
PropertyUtils.setProperty(Object bean, String name, Object value)
发现通用式最方便,可以替代上面所有的方式(搞不懂为啥还要弄那么多)。
举例:
//简单式
System.out.println(PropertyUtils.getProperty(employee1, "lastName"));
//索引式
System.out.println(PropertyUtils.getProperty(employee1,"addr[0].city"));
//Map式
PropertyUtils.setProperty(employee1, "telphone(tel)", "test1");
System.out.println(PropertyUtils.getProperty(employee1, "telphone(tel)"));
//嵌套式
String address = (String) PropertyUtils.getProperty(employee1, "address.addr");
System.out.println(address);
2. 动态Beans
基本式:(需要先定义属性然后才能使用,不推荐)
BasicDynaBean and BasicDynaClass
包装ResultSet式:(必须打开数据库连接可以使用,不推荐)
ResultSetDynaClass
包装RowSet式:(可以不用打开连接使用,推荐)
RowSetDynaClass
举例:
try {
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
Connection conn = DriverManager.getConnection(
"jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=java",
"sa", "sa");
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("select code,name from role");
RowSetDynaClass rsdc = new RowSetDynaClass(rs);
rs.close();
stmt.close();
List rows = rsdc.getRows();
for (Object object : rows) {
DynaBean row = (DynaBean) object;
System.out.println("Role code is " +
row.get("code") +
" and name is " + row.get("name"));
}
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
懒加载式:(方便实用,重点推荐)
LazyDynaBean
举例:
LazyDynaBean ldb = new LazyDynaBean();
ldb.set("test1", "tt");
ldb.set("test2", null);
ldb.set("test3", new Employee());
System.out.println(ldb.get("test1"));
System.out.println(ldb.get("test2"));//null
System.out.println(ldb.get("test3"));//显示Employee.toString()信息
并且也具有LazyDynaMap的功能。
3. 数据类型的转换
重点推荐BeanUtils.populate方法。
举例:
Address bean = new Address();
HashMap map = new HashMap();
map.put("zipCode1", "zipCode");
map.put("addr", new Long(1234));
map.put("city", "");
map.put("country", "country");
System.out.println(bean);
try {
BeanUtils.populate(bean, map);
} catch (IllegalAccessException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (InvocationTargetException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println(bean);
常利用在action填充vo时。
在学习当中,发现了两位前辈的类似总结,写得很好。
http://www.blogjava.net/sean/articles/Jakarta_Commons_Notes.html
http://calvin.javaeye.com/blog/92035
省了我不少时间,呵呵。