JSONObject和JSONArray使用
1.所依赖JAR包
要使程序可以运行必须引入JSON-lib包，JSON-lib包同时依赖于以下的JAR包：
- commons-lang.jar
- commons-beanutils.jar
- commons-collections.jar
- commons-logging.jar
- ezmorph.jar
- json-lib-2.2.2-jdk15.jar
2.Demo
2.1 应用场景:
- 后台的java类，如实体类、List、Set、Map转成json字符串发送到其它项目或者jsp端
- jsp端或者其它项目发送过来的json字符串，需要解析成l实体类、List、Set、Map等java类
2.2 Student实体类
package json; import java.util.Date; import java.util.List; import java.util.Map; import java.util.Set; public class Student { private int id; private String name; private String age; private Date birthDay; private List list; private Set set; private Map map; 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 getAge() { return age; } public void setAge(String age) { this.age = age; } public Date getBirthDay() { return birthDay; } public void setBirthDay(Date birthDay) { this.birthDay = birthDay; } public List getList() { return list; } public void setList(List list) { this.list = list; } public Set getSet() { return set; } public void setSet(Set set) { this.set = set; } public Map getMap() { return map; } public void setMap(Map map) { this.map = map; } @Override public String toString() { return "Student [id=" + id + ", name=" + name + ", age=" + age + ", birthDay=" + birthDay + ", list=" + list + ", set=" + set + ", map=" + map + "]"; } }
2.3 java对象序列化成json对象时，处理日期的处理类
package json; import java.text.SimpleDateFormat; import java.util.Date; import net.sf.json.JsonConfig; import net.sf.json.processors.JsonValueProcessor; /** * * @author yangguojun * java实体类转jsonObject时,日期处理类 */ public class JsonDateValueProcessor implements JsonValueProcessor { /** * 集合中实体类日期处理 */ @Override public Object processArrayValue(Object value , JsonConfig config) { // TODO Auto-generated method stub return processor(value); } /** * 当个实体类日期处理 */ @Override public Object processObjectValue(String propertyName, Object value, JsonConfig config) { return processor(value); } /** * 把日期对象转为字符串 * @param value * @return */ private Object processor(Object value){ SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); if(value instanceof Date){ return format.format(value); } return value == null ? "":value.toString(); } }
2.4 测试类
package json; import java.util.ArrayList; import java.util.Date; import java.util.HashMap; import java.util.HashSet; import net.sf.json.JSON; import net.sf.json.JSONArray; import net.sf.json.JSONObject; import net.sf.json.JsonConfig; public class JsonDemo { public static void main(String[] args) { //创建JSON对象的第一种方法 JSONObject jsonObj1 = new JSONObject(); jsonObj1.put("id", "1"); jsonObj1.put("name", "rose"); jsonObj1.put("age", 25); System.out.println("jsonObj1"+jsonObj1); //创建JSON对象的第二种方法 HashMap<String, Object> map = new HashMap<String,Object>(); map.put("id", "2"); map.put("name", "zhangsan"); map.put("age", "25"); JSONObject jsonObj2 = JSONObject.fromObject(map); System.out.println("jsonObj2"+jsonObj2); //创建一个JsonArray方法1 JSONArray jsonArray = new JSONArray(); jsonArray.add(0, "ZHULI"); jsonArray.add(1, "30"); jsonArray.add(2, "ALI"); System.out.println("jsonArray1：" + jsonArray); //创建JsonArray方法2 ArrayList<String> arrayList = new ArrayList<String>(); arrayList.add("柯文修"); arrayList.add("23"); arrayList.add("5"); System.out.println("jsonArray2：" + JSONArray.fromObject(arrayList)); //创建一个复杂JSON对象（JSON对象里有JSON数组） JSONObject jsonObj3 = new JSONObject(); jsonObj3.put("id", 3); jsonObj3.put("name", "lisi"); jsonObj3.put("age", 23); jsonObj3.put("arrayList", arrayList); System.out.println("jsonObj3"+jsonObj3); //创建一个复杂JSON数组(JSON数组里含有JSON对象)、 JSONArray jsonArray3 = new JSONArray(); jsonArray3.add("4"); jsonArray3.add("wangwu"); jsonArray3.add("26"); jsonArray3.add(map); System.out.println("jsonArray3"+jsonArray3); //把JSON字符串转为JSON对象 String jsonString = "{\"id\":3,\"name\":\"lisi\",\"age\":23,\"arrayList\":[\"ZHULI\",\"30\",\"ALI\"]}"; JSONObject jsonObj4 = JSONObject.fromObject(jsonString); System.out.println(jsonObj4.get("id")+"--"+jsonObj4.get("name")+"--"+jsonObj4.get("age")+ "--"+jsonObj4.get("arrayList")); //java实体类转为JSONObject Student stu = new Student(); stu.setId(1); stu.setName("罗志茂"); stu.setAge("23"); stu.setBirthDay(new Date()); stu.setList(arrayList); HashSet<Object> set = new HashSet<>(); set.add("6"); set.add("戚广辉"); set.add("25"); stu.setSet(set); stu.setMap(map); JsonConfig jsonConfig = new JsonConfig(); jsonConfig.registerJsonValueProcessor(Date.class, new JsonDateValueProcessor()); JSONObject jsonObj5 = JSONObject.fromObject(stu,jsonConfig); System.out.println("序列化:"+jsonObj5); //json转java实体类 Student student = (Student) JSONObject.toBean(jsonObj5, Student.class); System.out.println("反序列化:"+student); } }
2.5 测试结果
jsonObj1{"id":"1","name":"rose","age":25}
jsonObj2{"id":"2","age":"25","name":"zhangsan"}
jsonArray1：["ZHULI","30","ALI"]
jsonArray2：["柯文修","23","5"]
jsonObj3{"id":3,"name":"lisi","age":23,"arrayList":["柯文修","23","5"]}
jsonArray3["4","wangwu","26",{"id":"2","age":"25","name":"zhangsan"}]
3--lisi--23--["ZHULI","30","ALI"]
序列化:{"age":"23","birthDay":"2016-08-13 23:22:27","id":1,"list":["柯文修","23","5"],"map":{"id":"2","age":"25","name":"zhangsan"},"name":"罗志茂","set": ["戚广辉","6","25"]}
反序列化:Student [id=1, name=罗志茂, age=23, birthDay=Sat Aug 13 23:22:27 CST 2016, list=[柯文修, 23, 5], set=[戚广辉, 6, 25], map={id=2, name=zhangsan, age=25}]
