一,字符串转JSON对象
marketingActivityPO.getRuleContent()字符串类型数据格式如下:
{
"activityName":"测试",
"merchantsId":"",
"storeId":"",
"activityGuideWords":"",
"ruleContent":{
"fType":3,
"randomDown":"0.1",
"randomUp":"0.5",
"feeUnit":"2",
"feeNum":[
{
"fee":"100"
}
],
"grabTime":[
{
"beginTime":"10",
"endTime":"22"
}
],
"joinNum":"100"
},
"outActCode":"7520180622",
"expTime":"20180630",
"activityWhiteListFileId":102,
"activityBlackListFileId":90
}
com.alibaba.fastjson.JSONObject jsonObject =
com.alibaba.fastjson.JSONObject.parseObject(marketingActivityPO.getRuleContent());
String activityBlackListFileId = jsonObject.getString("activityBlackListFileId");
2,JSON字符串转地图
修改JSON字符串的值之后使用同时杰克逊的ObjectMapper的writeValueAsString方法可以把Java的对象转化成JSON字符串
Map<String,String> value = JSON.parseObject(marketingActivityPO.getRuleContent(), Map.class);
value.put("activityBlackListFileId", fileId+"");
ObjectMapper json = new ObjectMapper();
String newRuleContent = "";
try {
newRuleContent = json.writeValueAsString(value);
} catch (JsonProcessingException e) {
e.printStackTrace();
}
JSON.parseObject,是将Json的字符串转化为相应的对象; JSON.toJSONString则是将对象转化为Json的字符串
public class jsonTest {
public static void main(String[] args) {
/**
* json字符串转化为对象
*/
String jsonString = "{name:'Antony',age:'12',sex:'male',telephone:'88888'}";
Staff staff = JSON.parseObject(jsonString, Staff.class);
System.out.println(staff.toString());//Staff{name='Antony', age=12, sex='male', birthday=null}
/**
* 对象转化为json字符串
*/
String jsonStr = JSON.toJSONString(staff);
System.out.println(jsonStr);//{"age":12,"name":"Antony","sex":"male"}
}
}
3,JSON案例
首先定义三个字符串
//json字符串-简单对象型
private static final String JSON_OBJ_STR = "{\"studentName\":\"lily\",\"studentAge\":12}";
//json字符串-数组类型
private static final String JSON_ARRAY_STR = "[{\"studentName\":\"lily\",\"studentAge\":12},{\"studentName\":\"lucy\",\"studentAge\":15}]";
//复杂格式json字符串
private static final String COMPLEX_JSON_STR = "{\"teacherName\":\"crystall\",\"teacherAge\":27,\"course\":{\"courseName\":\"english\",\"code\":1270},\"students\":[{\"studentName\":\"lily\",\"studentAge\":12},{\"studentName\":\"lucy\",\"studentAge\":15}]}";
示例1:JSON格式字符串与JSON对象之间的转换。
示例1.1 JSON字符串 - 简单对象型与JSONObject的之间的转换
/**
* json字符串-简单对象型与JSONObject之间的转换
*/
public static void testJSONStrToJSONObject(){
JSONObject jsonObject = JSON.parseObject(JSON_OBJ_STR);
//JSONObject jsonObject1 = JSONObject.parseObject(JSON_OBJ_STR); //因为JSONObject继承了JSON,所以这样也是可以的
System.out.println(jsonObject.getString("studentName")+":"+jsonObject.getInteger("studentAge"));
}
示例1.2 JSON字符串 - 数组类型与JSONArray之间的转换
/**
* json字符串-数组类型与JSONArray之间的转换
*/
public static void testJSONStrToJSONArray(){
JSONArray jsonArray = JSON.parseArray(JSON_ARRAY_STR);
//JSONArray jsonArray1 = JSONArray.parseArray(JSON_ARRAY_STR);//因为JSONArray继承了JSON,所以这样也是可以的
//遍历方式1
int size = jsonArray.size();
for (int i = 0; i < size; i++){
JSONObject jsonObject = jsonArray.getJSONObject(i);
System.out.println(jsonObject.getString("studentName")+":"+jsonObject.getInteger("studentAge"));
}
//遍历方式2
for (Object obj : jsonArray) {
JSONObject jsonObject = (JSONObject) obj;
System.out.println(jsonObject.getString("studentName")+":"+jsonObject.getInteger("studentAge"));
}
}
示例1.3-复杂的JSON格式字符串与JSONObject的之间的转换
/**
* 复杂json格式字符串与JSONObject之间的转换
*/
public static void testComplexJSONStrToJSONObject(){
JSONObject jsonObject = JSON.parseObject(COMPLEX_JSON_STR);
//JSONObject jsonObject1 = JSONObject.parseObject(COMPLEX_JSON_STR);//因为JSONObject继承了JSON,所以这样也是可以的
String teacherName = jsonObject.getString("teacherName");
Integer teacherAge = jsonObject.getInteger("teacherAge");
JSONObject course = jsonObject.getJSONObject("course");
JSONArray students = jsonObject.getJSONArray("students");
}
示例2:JSON格式字符串与的javaBean之间的转换。
首先,我们针对数据源所示的字符串,提供三个的javaBean。
public class Student {
private String studentName;
private Integer studentAge;
public String getStudentName() {
return studentName;
}
public void setStudentName(String studentName) {
this.studentName = studentName;
}
public Integer getStudentAge() {
return studentAge;
}
public void setStudentAge(Integer studentAge) {
this.studentAge = studentAge;
}
}
public class Course {
private String courseName;
private Integer code;
public String getCourseName() {
return courseName;
}
public void setCourseName(String courseName) {
this.courseName = courseName;
}
public Integer getCode() {
return code;
}
public void setCode(Integer code) {
this.code = code;
}
}
public class Teacher {
private String teacherName;
private Integer teacherAge;
private Course course;
private List<Student> students;
public String getTeacherName() {
return teacherName;
}
public void setTeacherName(String teacherName) {
this.teacherName = teacherName;
}
public Integer getTeacherAge() {
return teacherAge;
}
public void setTeacherAge(Integer teacherAge) {
this.teacherAge = teacherAge;
}
public Course getCourse() {
return course;
}
public void setCourse(Course course) {
this.course = course;
}
public List<Student> getStudents() {
return students;
}
public void setStudents(List<Student> students) {
this.students = students;
}
}
json字符串与javaBean之间的转换推荐使用TypeReference <T>这个类,使用泛型可以更加清晰,当然也有其它的转换方式,这里就不做探讨了。
示例2.1 JSON字符串 - 简单对象型与javaBean的之间的转换
/**
* json字符串-简单对象与JavaBean_obj之间的转换
*/
public static void testJSONStrToJavaBeanObj(){
Student student = JSON.parseObject(JSON_OBJ_STR, new TypeReference<Student>() {});
//Student student1 = JSONObject.parseObject(JSON_OBJ_STR, new TypeReference<Student>() {});//因为JSONObject继承了JSON,所以这样也是可以的
System.out.println(student.getStudentName()+":"+student.getStudentAge());
}
示例2.2 JSON字符串 - 数组类型与javaBean的之间的转换
/**
* json字符串-数组类型与JavaBean_List之间的转换
*/
public static void testJSONStrToJavaBeanList(){
ArrayList<Student> students = JSON.parseObject(JSON_ARRAY_STR, new TypeReference<ArrayList<Student>>() {});
//ArrayList<Student> students1 = JSONArray.parseObject(JSON_ARRAY_STR, new TypeReference<ArrayList<Student>>() {});//因为JSONArray继承了JSON,所以这样也是可以的
for (Student student : students) {
System.out.println(student.getStudentName()+":"+student.getStudentAge());
}
}
示例2.3-复杂的JSON格式字符串与与javaBean的之间的转换
/**
* 复杂json格式字符串与JavaBean_obj之间的转换
*/
public static void testComplexJSONStrToJavaBean(){
Teacher teacher = JSON.parseObject(COMPLEX_JSON_STR, new TypeReference<Teacher>() {});
//Teacher teacher1 = JSON.parseObject(COMPLEX_JSON_STR, new TypeReference<Teacher>() {});//因为JSONObject继承了JSON,所以这样也是可以的
String teacherName = teacher.getTeacherName();
Integer teacherAge = teacher.getTeacherAge();
Course course = teacher.getCourse();
List<Student> students = teacher.getStudents();
}
此外的:
1,对于JSON对象与JSON格式字符串的转换可以直接用toJSONString()这个方法。
2的,JavaBean与JSON格式字符串之间的转换要用到:JSON.toJSONString(OBJ);
3的,JavaBean与JSON对象间的转换使用:JSON.toJSON(OBJ),然后使用强制类型转换,的JSONObject或者JSONArray。