json-lib的一些过滤操作

package demo4;

import java.io.Serializable;

import net.sf.json.JSONString;

public class User implements JSONString,Serializable{
    /**
     *
     */
    private static final long serialVersionUID = 1L;
    private long id;
    private String name;
    private String password;
    public long getId() {
        return id;
    }
    public void setId(long id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public User(long id, String name, String password) {
        super();
        this.id = id;
        this.name = name;
        this.password = password;
    }

    public User() {
        super();
    }

    public String toJSONString() {
        return "{\"id\":"+this.id+",\"name\":\""+this.name+"\"}";
    }

}

user.java

package demo4;

public class Teacher {
    private int id;
    private String name;
    private String password;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public Teacher(int id, String name, String password) {
        super();
        this.id = id;
        this.name = name;
        this.password = password;
    }
    public Teacher() {
        super();
    }

}

Teacher.java

package demo4;

import java.text.SimpleDateFormat;
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;

import net.sf.json.JSONObject;
import net.sf.json.JSONSerializer;
import net.sf.json.JsonConfig;
import net.sf.json.processors.JsonBeanProcessor;
import net.sf.json.processors.JsonValueProcessor;
import net.sf.json.util.PropertyFilter;

import org.junit.Test;

public class Demo {
    /*

    public void registerJsonBeanProcessor(Class target,
                                      JsonBeanProcessor jsonBeanProcessor)

    Registers a JsonBeanProcessor.
    [Java -> JSON]

    Parameters:
        target - the class to use as key
        jsonBeanProcessor - the processor to register

    public void registerPropertyExclusion(Class target,    *注册不转换的属性在类中 *
                                      String propertyName)

    Registers a exclusion for a target class.
    [Java -> JSON]

    Parameters:
        target - the class to use as key
        propertyName - the property to be excluded

    public void setExcludes(String[] excludes)  设置不转换的属性
        Sets the excludes to use.
        Will set default value ([]) if null.
        [Java -> JSON] 

    PropertyFilter: 属性过滤器
        一个方法：
         apply

    boolean apply(Object source,
              String name,
              Object value)

    Parameters:
        source - the owner of the property
        name - the name of the property
        value - the value of the property
    Returns:
        true if the property will be filtered out, false otherwise

     */

    /**
     * 忽略不必要属性重写该对象指定toJSONString方法测试
     */
    @Test
    public void fun(){
        User user=new User(12,"郭大侠","gz1234");
        JSONObject jo=JSONObject.fromObject(user);
        System.out.println(jo);
    }

    /**
     * 忽略不必要的属性，使用jsonConfig实现
     * 通过jsonconfig实例，对包含和需要排除的属性进行方便的添加或删除
     */
    @Test
    public void fun1(){
        Teacher t=new Teacher(12,"guodaxia","gz1234");
        JsonConfig config=new JsonConfig();
        config.setExcludes(new String[]{"password"});//设置排除password属性
        JSONObject jo=JSONObject.fromObject(t, config);
        System.out.println(jo);
    }

    /**
     * 测试使用属性过滤器达到前面的效果
     * 使用propertyFilter可以允许同时对需要排除的属性和类进行控制，这种控制还可以是双向的，也可以应用到json字符串到java对象
     */
    @Test
    public void fun2(){
        Teacher t=new Teacher(12,"guodaxia","gz1234");
        JsonConfig config=new JsonConfig();
        config.setJsonPropertyFilter(new PropertyFilter() {

            public boolean apply(Object source, String propertyName, Object value) {
                /**
                 * 就这样将Teacher类中的password属性过滤掉了
                 */
//                return source instanceof Teacher && "password".equalsIgnoreCase(propertyName);
                return  "password".equalsIgnoreCase(propertyName);//这个是测试它可以双向过滤
            }

        });
        JSONObject jo=JSONObject.fromObject(t, config);
        System.out.println(jo);
        JSONObject jo1=(JSONObject) JSONSerializer.toJSON("{'id':12,'name':'gz','password':'a12345'}", config);//这里使用JSONSerializer得到的JSON对象才有效可转换为Teacher对象，JSONObject.fromObject不行，不知为何
        Teacher tt=(Teacher) jo1.toBean(jo1, Teacher.class );
        System.out.println(tt.getId()+"--"+tt.getName()+"--"+tt.getPassword());

//        JSONObject jo1=JSONObject.fromObject("{'id':12,'name':'gz','password':'a12345'}",config);
//        Object tt=  JSONObject.toBean(jo1);
//        System.out.println(tt);

    }

    /**
     * 使用registerPropertyExclusion达到前面的效果
     */
    @Test
    public void fun3(){
        Teacher t=new Teacher(12,"guodaxia","gz1234");
        JsonConfig config=new JsonConfig();
        config.registerPropertyExclusion(Teacher.class, "password");
        JSONObject jo=JSONObject.fromObject(t, config);
        System.out.println(jo);

    }

    /**
     * 测试使用自定义JSONBeanProcessor
     * JsonBeanProcessor和实现JsonString很类似，返回一个代表原来目标对象的合法JSONObject
     *
     */
    @Test
    public void fun4(){
        JsonConfig config=new JsonConfig();
        config.registerJsonBeanProcessor(Teacher.class,new JsonBeanProcessor() {

            public JSONObject processBean(Object bean, JsonConfig config) {
                Teacher tea=(Teacher)bean;
                return new JSONObject().element("id", tea.getId()).element("name", tea.getName());
            }
        });
        Teacher t=new Teacher(12,"JSON","json");
        System.out.println(JSONObject.fromObject(t,config));

    }

    /**
     * 自定义JsonValueProcessor
     * 比如我们要控制JSON序列化过程中的Date对象的格式化以及数值的格式化，JsonValueProcessor是最好的选择
     * 该方法可以用来处理数据，进行格式化操作等等
     */
    @Test
    public void fun5(){
        Map<String,Object> map=new HashMap<String,Object>();
        map.put("date", new Date());
        map.put("dates", Arrays.asList(new Date()));
        JsonConfig config=new JsonConfig();
        config.registerJsonValueProcessor(Date.class, new JsonValueProcessor() {
            //自定义日期处理格式
            SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");

            /**
             *处理单个Date对象
             */
            public Object processObjectValue(String propertyName, Object date, JsonConfig config) {
                return sdf.format(date);
            }

            public Object processArrayValue(Object date, JsonConfig config) {
                return sdf.format(date);
            }
        });
        System.out.println(JSONObject.fromObject(map, config));

    }

}