fromObject将Java对象转换成json字符串，toBean将json对象转换成Java对象。
上面方法值得注意的是使用了JsonConfig这个对象，这个对象可以在序列化的时候对JavaObject的数据进行处理、过滤等。
上面的jsonConfig的registerJsonValueProcessor方法可以完成对象值的处理和修改，比如处理生日为null时，给一个特定的值。同样setJsonPropertyFilter和setJavaPropertyFilter都是完成对转换后的值的处理。
运行上面的代码可以在控制台看到如下结果：
==============Java Bean >>> JSON Object==================
{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"haha"}
==============Java Bean >>> JSON Array==================
[{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"haha"}]
==============Java Bean >>> JSON Object ==================
{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"haha"}
========================JsonConfig========================
key:birthday
{"address":"address","birthday":"2010-11-22##修改过的日期","email":"email","id":1,"name":"haha"}
2010-11-22##修改过的日期
haha#1#address#null#email
#####################JsonPropertyFilter############################
haha#1#address#2010-11-22#email%%%address--address
haha#1#address#2010-11-22#email%%%birthday--2010-11-22
haha#1#address#2010-11-22#email%%%email--email
haha#1#address#2010-11-22#email%%%id--1
haha#1#address#2010-11-22#email%%%name--haha
{"address":"address","email":"email","id":1,"name":"haha"}
#################JavaPropertyFilter##################
address@address#null#0#null#null#null
birthday@2010-11-22##修改过的日期#null#0#address#null#null
email@email#null#0#address#null#null
id@1#null#0#address#null#null
name@haha#null#0#address#null#null
Student:haha#0#address#null#null
{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"haha"}
==============Java Bean >>> JSON Array==================
[{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"haha"}]
==============Java Bean >>> JSON Object ==================
{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"haha"}
========================JsonConfig========================
key:birthday
{"address":"address","birthday":"2010-11-22##修改过的日期","email":"email","id":1,"name":"haha"}
2010-11-22##修改过的日期
haha#1#address#null#email
#####################JsonPropertyFilter############################
haha#1#address#2010-11-22#email%%%address--address
haha#1#address#2010-11-22#email%%%birthday--2010-11-22
haha#1#address#2010-11-22#email%%%email--email
haha#1#address#2010-11-22#email%%%id--1
haha#1#address#2010-11-22#email%%%name--haha
{"address":"address","email":"email","id":1,"name":"haha"}
#################JavaPropertyFilter##################
address@address#null#0#null#null#null
birthday@2010-11-22##修改过的日期#null#0#address#null#null
email@email#null#0#address#null#null
id@1#null#0#address#null#null
name@haha#null#0#address#null#null
Student:haha#0#address#null#null
2、 将JavaList集合转换吃JSON字符串
/**
* <b>function:</b>转换Java List集合到JSON
* @author hoojo
* @createDate Nov 28, 2010 2:36:15 PM
*/
@Test
public void writeList2JSON() {
fail("==============Java List >>> JSON Array==================");
List<Student> stu = new ArrayList<Student>();
stu.add(bean);
bean.setName("jack");
stu.add(bean);
fail(JSONArray.fromObject(stu).toString());
fail(JSONSerializer.toJSON(stu).toString());
}
运行此方法后，可以看到控制台输出：
==============Java List >>> JSON Array==================
[{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"jack"},
{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"jack"}]
[{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"jack"},
{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"jack"}]
* <b>function:</b>转换Java List集合到JSON
* @author hoojo
* @createDate Nov 28, 2010 2:36:15 PM
*/
@Test
public void writeList2JSON() {
fail("==============Java List >>> JSON Array==================");
List<Student> stu = new ArrayList<Student>();
stu.add(bean);
bean.setName("jack");
stu.add(bean);
fail(JSONArray.fromObject(stu).toString());
fail(JSONSerializer.toJSON(stu).toString());
}
运行此方法后，可以看到控制台输出：
==============Java List >>> JSON Array==================
[{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"jack"},
{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"jack"}]
[{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"jack"},
{"address":"address","birthday":{"birthday":"2010-11-22"},"email":"email","id":1,"name":"jack"}]
如果你是转换List集合，一定得用JSONArray或是JSONSrializer提供的序列化方法。如果你用JSONObject.fromObject方法转换List会出现异常，通常使用JSONSrializer这个JSON序列化的方法，它会自动识别你传递的对象的类型，然后转换成相应的JSON字符串。
