ognl表达式入门应用
package foo.test;public class User {private Person person;private String username;private String sex;public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public Person getPerson() {return person;}public void setPerson(Person person) {this.person = person;}public String getUsername() {return username;}public void setUsername(String username) {this.username = username;}}package foo.test;public class Person {private String name;public String getName() {return name;}public void setName(String name) {this.name = name;}}package foo.test;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import ognl.Ognl;public class OgnlTest {public static void main(String[] args) throws Exception{new OgnlTest().testOgnl_01();}// ***************** root对象的概念 ******************* // public void testOgnl_01() throws Exception{ User user = new User(); user.setUsername("暗之幻影"); user.setSex("男"); //相当于调用user.getUsername()方法 String value = (String)Ognl.getValue("username + ',' + sex", user); System.out.println(value); } public void testOgnl_02() throws Exception{ User user = new User(); Person p = new Person(); p.setName("暗之幻影"); user.setPerson(p); //相当于调用user.getPerson().getName()方法 String value = (String)Ognl.getValue("person.name", user); System.out.println(value); } public void testOgnl_03() throws Exception{ User user = new User(); Person p = new Person(); p.setName("暗之幻影"); user.setPerson(p); //可以使用#root来引用根对象，相当于调用user.getPerson().getName()方法 String value = (String)Ognl.getValue("#root.person.name", user); System.out.println(value); } // *********************** context的概念 **********************// public void testOgnl_04() throws Exception{ Person p1 = new Person(); Person p2 = new Person(); p1.setName("风"); p2.setName("云"); Map<String,Person> context = new HashMap<String,Person>(); context.put("p1", p1); context.put("p2", p2); // 需要加上#才表示到context中取数据，否则表示从根目录下取值 String value = (String)Ognl.getValue("#p1.name + ',' + #p2.name", context, new Object()); System.out.println(value); } public void testOgnl_05() throws Exception{ Person p1 = new Person(); Person p2 = new Person(); p1.setName("风"); p2.setName("云"); Map<String,Person> context = new HashMap<String,Person>(); context.put("p1", p1); context.put("p2", p2); User root = new User(); root.setUsername("雨"); String value = (String)Ognl.getValue("#p1.name + ',' + #p2.name + ',' + username", context, root); System.out.println(value); } // ******************* OGNL赋值操作 ************************// public void testOgnl_06() throws Exception{ User user = new User(); //给root对象的属性赋值，相当于调用user.setUsername() Ognl.setValue("username", user, "暗之幻影"); System.out.println(user.getUsername()); } public void testOgnl_07() throws Exception{ User user = new User(); Map<String, User> context = new HashMap<String, User>(); context.put("u", user); //给context中的对象属性赋值，相当于调用user.setUsername() Ognl.setValue("#u.username", context, new Object(), "暗之幻影"); System.out.println(user.getUsername()); } public void testOgnl_08() throws Exception{ User user = new User(); Map<String, User> context = new HashMap<String, User>(); context.put("u", user); //给context中的对象属性赋值，相当于调用user.setUsername() //在表达式中使用=赋值操作符来赋值 Ognl.getValue("#u.username = '暗之幻影'",context, new Object()); System.out.println(user.getUsername()); } public void testOgnl_09() throws Exception{ User user = new User(); Person p = new Person(); Map<String,Object> context = new HashMap<String,Object>(); context.put("u", user); context.put("p", p); //给context中的对象属性赋值，相当于调用user.setUsername() //在表达式中使用=赋值操作符来赋值 Ognl.getValue("#u.username = '风',#p.name = '云'",context, new Object()); System.out.println(user.getUsername()+","+p.getName()); } //****************** 使用OGNL调用对象的方法 **********************// public void testOgnl_10() throws Exception{ User user = new User(); user.setUsername("暗之幻影"); String value = (String)Ognl.getValue("getUsername()", user); System.out.println(value); } public void testOgnl_11() throws Exception{ User user = new User(); Ognl.getValue("setUsername('暗之幻影')", user); System.out.println(user.getUsername()); } // ******************* OGNL调用类变量、静态方法 *************************// public void testOgnl_12() throws Exception{ User user = new User(); Ognl.getValue("setUsername('暗之幻影')", user); Ognl.getValue("@System@out.println(username)", user); } public void testOgnl_13() throws Exception{ User user = new User(); Ognl.getValue("setUsername('暗之幻影')", user); Ognl.getValue("@System@out.println(@org.darkness.struts2.test.Utils@toLowerCase(username))", user); } // ********************* OGNL中的this表达式 **********************// public void testOgnl_14() throws Exception{ Object root = new Object(); Map context = new HashMap(); List values = new ArrayList(); for(int i=0; i<11; i++){ values.add(i); } context.put("values", values); Ognl.getValue("@System@out.println(#values.size.(#this > 10 ? "大于10" : '不大于10'))", context, root); } public void testOgnl_15() throws Exception{ User user = new User(); Ognl.getValue("setUsername('暗之幻影')", user); Ognl.getValue("@System@out.println(#this.username)", user); } public void testOgnl_16() throws Exception{ User user = new User(); Ognl.getValue("setUsername('暗之幻影')", user); Ognl.getValue("@System@out.println(username.(#this.toLowerCase()))", user); } // ******************* 如何把表达式的解释结果作为另外一个表达式,OGNL中括号的使用 **********************// public void testOgnl_17() throws Exception{ Object root = new Object(); Map context = new HashMap(); User u = new User(); u.setUsername("暗之幻影"); context.put("u", u); context.put("fact", "username"); /** * 1、首先把#fact表达式进行解释，得到一个值：username * 2、解释括号中的表达式#u，其结果是user对象 * 3、把括号中表达式的结果作为root对象，解释在第一步中得到的结果（即把第一步的结果看成另外一个表达式） */ String value = (String)Ognl.getValue("#fact(#u)", context, root); System.out.println(value); } public void testOgnl_18() throws Exception{ Person person = new Person(); Map context = new HashMap(); User u = new User(); u.setUsername("暗之幻影"); context.put("u", u); /** * 相当于调用person这个根对象的fact方法，并把#u的解释结果作为参数传入此方法 */ String value = (String)Ognl.getValue("fact(#u)", context, person); System.out.println(value); //输出是 "暗之幻影," } public void testOgnl_19() throws Exception{ Person person = new Person(); Map context = new HashMap(); User u = new User(); u.setUsername("暗之幻影"); context.put("u", u); /** * 1、先计算表达式fact，得到结果是：username * 2、解释括号中的表达式#u，其结果是user对象 * 3、把括号中表达式的结果作为root对象，解释在第一步中得到的结果（即把第一步的结果看成另外一个表达式） */ String value = (String)Ognl.getValue("(fact)(#u)", context, person); System.out.println(value); //输出"暗之幻影" } // ********************* OGNL访问集合元素 **************************// public void testOgnl_20() throws Exception{ Object root = new Object(); Map context = new HashMap(); //用OGNL创建List对象 List listvalue = (List)Ognl.getValue("{123,'暗之幻影','风之水影'}", context, root); context.put("listvalue", listvalue); //用OGNL创建数组 int[] intarray= (int[])Ognl.getValue("new int[]{23,45,67}", context, root); context.put("intarray", intarray); //用OGNL创建Map对象 Map mapvalue = (Map)Ognl.getValue("#{'listvalue':#listvalue,'intarray':#intarray}", context, root); context.put("mapvalue", mapvalue); Ognl.getValue("@System@out.println(#listvalue[0])", context, root); Ognl.getValue("@System@out.println(#intarray[1])", context, root); Ognl.getValue("@System@out.println(#mapvalue['intarray'][2])", context, root); Ognl.getValue("@System@out.println(#mapvalue.intarray[0])", context, root); } }