1.1.FastJson的介绍:
JSON协议使用方便，越来越流行,JSON的处理器有很多,这里我介绍一下FastJson,FastJson是阿里的开源框架,被不少企业使用,是一个极其优秀的Json框架,Github地址: FastJson
1.2.FastJson的特点:
1.FastJson数度快,无论序列化和反序列化,都是当之无愧的fast 2.功能强大(支持普通JDK类包括任意Java Bean Class、Collection、Map、Date或enum) 3.零依赖(没有依赖其它任何类库)
1.3.FastJson的简单说明:
FastJson对于json格式字符串的解析主要用到了下面三个类： 1.JSON：fastJson的解析器，用于JSON格式字符串与JSON对象及javaBean之间的转换 2.JSONObject：fastJson提供的json对象 3.JSONArray：fastJson提供json数组对象
2.FastJson的用法
首先定义三个json格式的字符串
private static final String JSON_OBJ_STR =
"{\"studentName\":\"lily\",\"studentAge\":12}";
private static final String JSON_ARRAY_STR =
"[{\"studentName\":\"lily\",\"studentAge\":12},{\"studentName\":\"lucy\",\"studentAge\":15}]";
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}]}";
2.1.JSON格式字符串与JSON对象之间的转换
2.1.1.json字符串-简单对象型与JSONObject之间的转换
@Test
public void testJSONStrToJSONObject() {
JSONObject jsonObject = JSONObject.parseObject(JSON_OBJ_STR);
System.out.println(
"studentName: " + jsonObject.getString(
"studentName") +
":" +
" studentAge: "
+ jsonObject.getInteger(
"studentAge"));
}
@Test
public void testJSONObjectToJSONStr() {
JSONObject jsonObject = JSONObject.parseObject(JSON_OBJ_STR);
String jsonString = JSONObject.toJSONString(jsonObject);
System.out.println(jsonString);
}
2.1.2.json字符串(数组类型)与JSONArray之间的转换
@Test
public void testJSONStrToJSONArray() {
JSONArray jsonArray = JSONArray.parseArray(JSON_ARRAY_STR);
int size = jsonArray.size();
for (
int i =
0; i < size; i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
System.out.println(
"studentName: " + jsonObject.getString(
"studentName") +
":" +
" studentAge: "
+ jsonObject.getInteger(
"studentAge"));
}
for (Object obj : jsonArray) {
JSONObject jsonObject = (JSONObject) obj;
System.out.println(
"studentName: " + jsonObject.getString(
"studentName") +
":" +
" studentAge: "
+ jsonObject.getInteger(
"studentAge"));
}
}
@Test
public void testJSONArrayToJSONStr() {
JSONArray jsonArray = JSONArray.parseArray(JSON_ARRAY_STR);
String jsonString = JSONArray.toJSONString(jsonArray);
System.out.println(jsonString);
}
2.1.3.复杂json格式字符串与JSONObject之间的转换
@Test
public void testComplexJSONStrToJSONObject() {
JSONObject jsonObject = JSONObject.parseObject(COMPLEX_JSON_STR);
String teacherName = jsonObject.getString(
"teacherName");
Integer teacherAge = jsonObject.getInteger(
"teacherAge");
System.out.println(
"teacherName: " + teacherName +
" teacherAge: " + teacherAge);
JSONObject jsonObjectcourse = jsonObject.getJSONObject(
"course");
String courseName = jsonObjectcourse.getString(
"courseName");
Integer code = jsonObjectcourse.getInteger(
"code");
System.out.println(
"courseName: " + courseName +
" code: " + code);
JSONArray jsonArraystudents = jsonObject.getJSONArray(
"students");
for (Object object : jsonArraystudents) {
JSONObject jsonObjectone = (JSONObject) object;
String studentName = jsonObjectone.getString(
"studentName");
Integer studentAge = jsonObjectone.getInteger(
"studentAge");
System.out.println(
"studentName: " + studentName +
" studentAge: " + studentAge);
}
}
@Test
public void testJSONObjectToComplexJSONStr() {
JSONObject jsonObject = JSONObject.parseObject(COMPLEX_JSON_STR);
String jsonString = jsonObject.toJSONString();
System.out.println(jsonString);
}
2.2.JSON格式字符串与javaBean之间的转换
2.2.1.json字符串-简单对象型与javaBean之间的转换
@Test
public void testJSONStrToJavaBeanObj() {
JSONObject jsonObject = JSONObject.parseObject(JSON_OBJ_STR);
String studentName = jsonObject.getString(
"studentName");
Integer studentAge = jsonObject.getInteger(
"studentAge");
Student student = JSONObject.parseObject(JSON_OBJ_STR, Student.class);
System.out.println(student);
}
@Test
public void testJavaBeanObjToJSONStr() {
Student student =
new Student(
"lily",
12);
String jsonString = JSONObject.toJSONString(student);
System.out.println(jsonString);
}
2.2.2.json字符串-数组类型与javaBean之间的转换
@Test
public void testJSONStrToJavaBeanList() {
JSONArray jsonArray = JSONArray.parseArray(JSON_ARRAY_STR);
List<Student> students =
new ArrayList<Student>();
Student student =
null;
for (Object object : jsonArray) {
JSONObject jsonObjectone = (JSONObject) object;
String studentName = jsonObjectone.getString(
"studentName");
Integer studentAge = jsonObjectone.getInteger(
"studentAge");
student =
new Student(studentName,studentAge);
students.add(student);
}
System.out.println(
"students: " + students);
List<Student> studentList = JSONArray.parseObject(JSON_ARRAY_STR,
new TypeReference<ArrayList<Student>>() {});
System.out.println(
"studentList: " + studentList);
List<Student> studentList1 = JSONArray.parseArray(JSON_ARRAY_STR, Student.class);
System.out.println(
"studentList1: " + studentList1);
}
@Test
public void testJavaBeanListToJSONStr() {
Student student =
new Student(
"lily",
12);
Student studenttwo =
new Student(
"lucy",
15);
List<Student> students =
new ArrayList<Student>();
students.add(student);
students.add(studenttwo);
String jsonString = JSONArray.toJSONString(students);
System.out.println(jsonString);
}
2.2.3.复杂json格式字符串与与javaBean之间的转换
@Test
public void testComplexJSONStrToJavaBean(){
Teacher teacher = JSONObject.parseObject(COMPLEX_JSON_STR,
new TypeReference<Teacher>() {});
System.out.println(teacher);
Teacher teacher1 = JSONObject.parseObject(COMPLEX_JSON_STR, Teacher.class);
System.out.println(teacher1);
}
@Test
public void testJavaBeanToComplexJSONStr(){
Teacher teacher = JSONObject.parseObject(COMPLEX_JSON_STR,
new TypeReference<Teacher>() {});
String jsonString = JSONObject.toJSONString(teacher);
System.out.println(jsonString);
}
2.3.javaBean与json对象间的之间的转换
2.3.1.简单javaBean与json对象之间的转换
@Test
public void testJavaBeanToJSONObject(){
Student student =
new Student(
"lily",
12);
String jsonString = JSONObject.toJSONString(student);
JSONObject jsonObject = JSONObject.parseObject(jsonString);
System.out.println(jsonObject);
JSONObject jsonObject1 = (JSONObject) JSONObject.toJSON(student);
System.out.println(jsonObject1);
}
@Test
public void testJSONObjectToJavaBean(){
JSONObject jsonObject = JSONObject.parseObject(JSON_OBJ_STR);
Student student = JSONObject.parseObject(jsonObject.toJSONString(),
new TypeReference<Student>() {});
System.out.println(student);
Student student1 = JSONObject.parseObject(jsonObject.toJSONString(), Student.class);
System.out.println(student1);
}
2.3.2.JavaList与JsonArray之间的转换
@Test
public void testJavaListToJsonArray() {
Student student =
new Student(
"lily",
12);
Student studenttwo =
new Student(
"lucy",
15);
List<Student> students =
new ArrayList<Student>();
students.add(student);
students.add(studenttwo);
String jsonString = JSONArray.toJSONString(students);
JSONArray jsonArray = JSONArray.parseArray(jsonString);
System.out.println(jsonArray);
JSONArray jsonArray1 = (JSONArray) JSONArray.toJSON(students);
System.out.println(jsonArray1);
}
@Test
public void testJsonArrayToJavaList() {
JSONArray jsonArray = JSONArray.parseArray(JSON_ARRAY_STR);
ArrayList<Student> students = JSONArray.parseObject(jsonArray.toJSONString(),
new TypeReference<ArrayList<Student>>() {});
System.out.println(students);
List<Student> students1 = JSONArray.parseArray(jsonArray.toJSONString(), Student.class);
System.out.println(students1);
}
2.3.3.复杂JavaBean_obj与json对象之间的转换
@Test
public void testComplexJavaBeanToJSONObject() {
Student student =
new Student(
"lily",
12);
Student studenttwo =
new Student(
"lucy",
15);
List<Student> students =
new ArrayList<Student>();
students.add(student);
students.add(studenttwo);
Course course =
new Course(
"english",
1270);
Teacher teacher =
new Teacher(
"crystall",
27, course, students);
String jsonString = JSONObject.toJSONString(teacher);
JSONObject jsonObject = JSONObject.parseObject(jsonString);
System.out.println(jsonObject);
JSONObject jsonObject1 = (JSONObject) JSONObject.toJSON(teacher);
System.out.println(jsonObject1);
}
@Test
public void testComplexJSONObjectToJavaBean() {
JSONObject jsonObject = JSONObject.parseObject(COMPLEX_JSON_STR);
Teacher teacher = JSONObject.parseObject(jsonObject.toJSONString(),
new TypeReference<Teacher>() {});
System.out.println(teacher);
Teacher teacher1 = JSONObject.parseObject(jsonObject.toJSONString(), Teacher.class);
System.out.println(teacher1);
}
3.源码
本篇博客的源码都在我的Github上,FastJsonDemo,欢迎大家Fork and Star!
4.总结
好啦,FastJson的基本用法就介绍完了,送人玫瑰,手留余香,学习使我快乐,分享让大家快乐,欢迎大家点赞收藏噢!
