依赖
<dependency> <groupId>com.alibaba</groupId> <artifactId>fastjson</artifactId> <version>1.2.7</version> </dependency>
SerializerFeature属性
示例
准备
- User、Word来模拟各种数据类型。
- SerializerFeatureTest：JSON部分示例的示例方法。
User类型：缺省get、set方法
public class User {
private int id;
private String name;
private String add;
private String old;
}
Word类型：缺省get、set方法
public class Word {
private String d;
private String e;
private String f;
private String a;
private int b;
private boolean c;
private Date date;
private Map<String , Object> map;
private List<User> list;
}
SerializerFeatureTest:测试类
public class SerializerFeatureTest {
private static Word word;
private static void init() {
word = new Word();
word.setA("a");
word.setB(2);
word.setC(true);
word.setD("d");
word.setE("");
word.setF(null);
word.setDate(new Date());
List<User> list = new ArrayList<User>();
User user1 = new User();
user1.setId(1);
user1.setOld("11");
user1.setName("用户1");
user1.setAdd("北京");
User user2 = new User();
user2.setId(2);
user2.setOld("22");
user2.setName("用户2");
user2.setAdd("上海");
User user3 = new User();
user3.setId(3);
user3.setOld("33");
user3.setName("用户3");
user3.setAdd("广州");
list.add(user3);
list.add(user2);
list.add(null);
list.add(user1);
word.setList(list);
Map<String , Object> map = new HashedMap();
map.put("mapa", "mapa");
map.put("mapo", "mapo");
map.put("mapz", "mapz");
map.put("user1", user1);
map.put("user3", user3);
map.put("user4", null);
map.put("list", list);
word.setMap(map);
}
public static void main(String[] args) {
init();
// useSingleQuotes();
// writeMapNullValue();
// useISO8601DateFormat();
// writeNullListAsEmpty();
// writeNullStringAsEmpty();
// sortField();
// prettyFormat();
// writeDateUseDateFormat();
// beanToArray();
showJsonBySelf();
}
/**
* 9:自定义
* 格式化输出
* 显示值为null的字段
* 将为null的字段值显示为""
* DisableCircularReferenceDetect:消除循环引用
*/
private static void showJsonBySelf() {
System.out.println(JSON.toJSONString(word));
System.out.println(JSON.toJSONString(word, SerializerFeature.PrettyFormat,
SerializerFeature.WriteMapNullValue, SerializerFeature.WriteNullStringAsEmpty,
SerializerFeature.DisableCircularReferenceDetect,
SerializerFeature.WriteNullListAsEmpty));
}
/**
* 8:
* 将对象转为array输出
*/
private static void beanToArray() {
word.setMap(null);
word.setList(null);
System.out.println(JSON.toJSONString(word));
System.out.println(JSON.toJSONString(word, SerializerFeature.BeanToArray));
}
/**
* 7:
* WriteDateUseDateFormat:全局修改日期格式,默认为false。
*/
private static void writeDateUseDateFormat() {
word.setMap(null);
word.setList(null);
System.out.println(JSON.toJSONString(word));
JSON.DEFFAULT_DATE_FORMAT = "yyyy-MM-dd";
System.out.println(JSON.toJSONString(word, SerializerFeature.WriteDateUseDateFormat));
}
/**
* 6:
* PrettyFormat
*/
private static void prettyFormat() {
word.setMap(null);
word.setList(null);
System.out.println(JSON.toJSONString(word));
System.out.println(JSON.toJSONString(word, SerializerFeature.PrettyFormat));
}
/**
* SortField:按字段名称排序后输出。默认为false
* 这里使用的是fastjson：为了更好使用sort field martch优化算法提升parser的性能，fastjson序列化的时候，
* 缺省把SerializerFeature.SortField特性打开了。
* 反序列化的时候也缺省把SortFeidFastMatch的选项打开了。
* 这样，如果你用fastjson序列化的文本，输出的结果是按照fieldName排序输出的，parser时也能利用这个顺序进行优化读取。
* 这种情况下，parser能够获得非常好的性能。
*/
private static void sortField() {
System.out.println(JSON.toJSONString(word));
System.out.println(JSON.toJSONString(word, SerializerFeature.SortField));
}
/**
* 5:
* WriteNullStringAsEmpty:字符类型字段如果为null,输出为"",而非null
* 需要配合WriteMapNullValue使用，现将null输出
*/
private static void writeNullStringAsEmpty() {
word.setE(null);
System.out.println(JSONObject.toJSONString(word));
System.out.println("设置WriteMapNullValue后：");
System.out.println(JSONObject.toJSONString(word, SerializerFeature.WriteMapNullValue));
System.out.println("设置WriteMapNullValue、WriteNullStringAsEmpty后：");
System.out.println(JSONObject.toJSONString(word, SerializerFeature.WriteMapNullValue, SerializerFeature.WriteNullStringAsEmpty));
}
/**
* 4:
* WriteNullListAsEmpty:List字段如果为null,输出为[],而非null
* 需要配合WriteMapNullValue使用，现将null输出
*/
private static void writeNullListAsEmpty() {
word.setList(null);
System.out.println(JSONObject.toJSONString(word));
System.out.println("设置WriteNullListAsEmpty后：");
System.out.println(JSONObject.toJSONString(word, SerializerFeature.WriteMapNullValue, SerializerFeature.WriteNullListAsEmpty));
}
/**
* 3:
* UseISO8601DateFormat:Date使用ISO8601格式输出，默认为false
*/
private static void useISO8601DateFormat() {
System.out.println(JSONObject.toJSONString(word));
System.out.println("设置UseISO8601DateFormat后：");
System.out.println(JSONObject.toJSONString(word, SerializerFeature.UseISO8601DateFormat));
}
/**
* 2:
* WriteMapNullValue:是否输出值为null的字段,默认为false
*/
private static void writeMapNullValue() {
System.out.println(JSONObject.toJSONString(word));
System.out.println("设置WriteMapNullValue后：");
System.out.println(JSONObject.toJSONString(word, SerializerFeature.WriteMapNullValue));
}
/**
* 1:
* UseSingleQuotes:使用单引号而不是双引号,默认为false
*/
private static void useSingleQuotes() {
System.out.println(JSONObject.toJSONString(word));
System.out.println("设置useSingleQuotes后：");
System.out.println(JSONObject.toJSONString(word, SerializerFeature.UseSingleQuotes));
}
}
对应输出结果如下：
-
1、useSingleQuotes：
2、writeMapNullValue：
3、useISO8601DateFormat：
4、writeNullListAsEmpty：
5、writeNullStringAsEmpty：
6、prettyFormat：
7、writeDateUseDateFormat：
8、beanToArray：
9、自定义组合：showJsonBySelf：
