高性能JSON框架之FastJson的簡(jiǎn)單使用、

1.前言
1.1.FastJson的介紹:
JSON協(xié)議使用方便，越來(lái)越流行,JSON的處理器有很多,這里我介紹一下FastJson,FastJson是阿里的開(kāi)源框架,被不少企業(yè)使用,是一個(gè)極其優(yōu)秀的Json框架,Github地址: FastJson

1.2.FastJson的特點(diǎn):
1.FastJson數(shù)度快,無(wú)論序列化和反序列化,都是當(dāng)之無(wú)愧的fast
2.功能強(qiáng)大(支持普通JDK類包括任意Java Bean Class、Collection、Map、Date或enum)
3.零依賴(沒(méi)有依賴其它任何類庫(kù))

1.3.FastJson的簡(jiǎn)單說(shuō)明:
FastJson對(duì)于json格式字符串的解析主要用到了下面三個(gè)類：
1.JSON：fastJson的解析器，用于JSON格式字符串與JSON對(duì)象及javaBean之間的轉(zhuǎn)換
2.JSONObject：fastJson提供的json對(duì)象
3.JSONArray：fastJson提供json數(shù)組對(duì)象

2.FastJson的用法
首先定義三個(gè)json格式的字符串

//json字符串-簡(jiǎn)單對(duì)象型
private static final String  JSON_OBJ_STR = "{\"studentName\":\"lily\",\"studentAge\":12}";//json字符串-數(shù)組類型
private static final String  JSON_ARRAY_STR = "[{\"studentName\":\"lily\",\"studentAge\":12},{\"studentName\":\"lucy\",\"studentAge\":15}]";//復(fù)雜格式j(luò)son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}]}";

2.1.JSON格式字符串與JSON對(duì)象之間的轉(zhuǎn)換
2.1.1.json字符串-簡(jiǎn)單對(duì)象型與JSONObject之間的轉(zhuǎn)換

/*** json字符串-簡(jiǎn)單對(duì)象型到JSONObject的轉(zhuǎn)換*/
@Test
public void testJSONStrToJSONObject() {JSONObject jsonObject = JSONObject.parseObject(JSON_OBJ_STR);System.out.println("studentName:  " + jsonObject.getString("studentName") + ":" + "  studentAge:  "+ jsonObject.getInteger("studentAge"));}/*** JSONObject到j(luò)son字符串-簡(jiǎn)單對(duì)象型的轉(zhuǎn)換*/
@Test
public void testJSONObjectToJSONStr() {//已知JSONObject,目標(biāo)要轉(zhuǎn)換為json字符串JSONObject jsonObject = JSONObject.parseObject(JSON_OBJ_STR);// 第一種方式String jsonString = JSONObject.toJSONString(jsonObject);// 第二種方式//String jsonString = jsonObject.toJSONString();System.out.println(jsonString);
}

2.1.2.json字符串(數(shù)組類型)與JSONArray之間的轉(zhuǎn)換

/*** json字符串-數(shù)組類型到JSONArray的轉(zhuǎn)換*/
@Test
public void testJSONStrToJSONArray() {JSONArray jsonArray = JSONArray.parseArray(JSON_ARRAY_STR);//遍歷方式1int 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"));}//遍歷方式2for (Object obj : jsonArray) {JSONObject jsonObject = (JSONObject) obj;System.out.println("studentName:  " + jsonObject.getString("studentName") + ":" + "  studentAge:  "+ jsonObject.getInteger("studentAge"));}
}/*** JSONArray到j(luò)son字符串-數(shù)組類型的轉(zhuǎn)換*/
@Test
public void testJSONArrayToJSONStr() {//已知JSONArray,目標(biāo)要轉(zhuǎn)換為json字符串JSONArray jsonArray = JSONArray.parseArray(JSON_ARRAY_STR);//第一種方式String jsonString = JSONArray.toJSONString(jsonArray);// 第二種方式//String jsonString = jsonArray.toJSONString(jsonArray);System.out.println(jsonString);
}

2.1.3.復(fù)雜json格式字符串與JSONObject之間的轉(zhuǎn)換

/*** 復(fù)雜json格式字符串到JSONObject的轉(zhuǎn)換*/
@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");//獲取JSONObject中的數(shù)據(jù)String courseName = jsonObjectcourse.getString("courseName");Integer code = jsonObjectcourse.getInteger("code");System.out.println("courseName:  " + courseName + "   code:  " + code);JSONArray jsonArraystudents = jsonObject.getJSONArray("students");//遍歷JSONArrayfor (Object object : jsonArraystudents) {JSONObject jsonObjectone = (JSONObject) object;String studentName = jsonObjectone.getString("studentName");Integer studentAge = jsonObjectone.getInteger("studentAge");System.out.println("studentName:  " + studentName + "   studentAge:  " + studentAge);}
}/*** 復(fù)雜JSONObject到j(luò)son格式字符串的轉(zhuǎn)換*/
@Test
public void testJSONObjectToComplexJSONStr() {//復(fù)雜JSONObject,目標(biāo)要轉(zhuǎn)換為json字符串JSONObject jsonObject = JSONObject.parseObject(COMPLEX_JSON_STR);//第一種方式//String jsonString = JSONObject.toJSONString(jsonObject);//第二種方式String jsonString = jsonObject.toJSONString();System.out.println(jsonString);}

2.2.JSON格式字符串與javaBean之間的轉(zhuǎn)換
2.2.1.json字符串-簡(jiǎn)單對(duì)象型與javaBean之間的轉(zhuǎn)換

/*** json字符串-簡(jiǎn)單對(duì)象到JavaBean之間的轉(zhuǎn)換*/
@Test
public void testJSONStrToJavaBeanObj() {//第一種方式JSONObject jsonObject = JSONObject.parseObject(JSON_OBJ_STR);String studentName = jsonObject.getString("studentName");Integer studentAge = jsonObject.getInteger("studentAge");//Student student = new Student(studentName, studentAge);//第二種方式,使用TypeReference<T>類,由于其構(gòu)造方法使用protected進(jìn)行修飾,故創(chuàng)建其子類//Student student = JSONObject.parseObject(JSON_OBJ_STR, new TypeReference<Student>() {});//第三種方式,使用Gson的思想Student student = JSONObject.parseObject(JSON_OBJ_STR, Student.class);System.out.println(student);
}/*** JavaBean到j(luò)son字符串-簡(jiǎn)單對(duì)象的轉(zhuǎn)換*/
@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-數(shù)組類型與javaBean之間的轉(zhuǎn)換

/*** json字符串-數(shù)組類型到JavaBean_List的轉(zhuǎn)換*/
@Test
public void testJSONStrToJavaBeanList() {//第一種方式JSONArray jsonArray = JSONArray.parseArray(JSON_ARRAY_STR);//遍歷JSONArrayList<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);//第二種方式,使用TypeReference<T>類,由于其構(gòu)造方法使用protected進(jìn)行修飾,故創(chuàng)建其子類List<Student> studentList = JSONArray.parseObject(JSON_ARRAY_STR, new TypeReference<ArrayList<Student>>() {});System.out.println("studentList:  " + studentList);//第三種方式,使用Gson的思想List<Student> studentList1 = JSONArray.parseArray(JSON_ARRAY_STR, Student.class);System.out.println("studentList1:  " + studentList1);}/*** JavaBean_List到j(luò)son字符串-數(shù)組類型的轉(zhuǎn)換*/
@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.復(fù)雜json格式字符串與與javaBean之間的轉(zhuǎn)換

/*** 復(fù)雜json格式字符串到JavaBean_obj的轉(zhuǎn)換*/
@Test
public void testComplexJSONStrToJavaBean(){//第一種方式,使用TypeReference<T>類,由于其構(gòu)造方法使用protected進(jìn)行修飾,故創(chuàng)建其子類Teacher teacher = JSONObject.parseObject(COMPLEX_JSON_STR, new TypeReference<Teacher>() {});System.out.println(teacher);//第二種方式,使用Gson思想Teacher teacher1 = JSONObject.parseObject(COMPLEX_JSON_STR, Teacher.class);System.out.println(teacher1);
}/*** 復(fù)雜JavaBean_obj到j(luò)son格式字符串的轉(zhuǎn)換*/
@Test
public void testJavaBeanToComplexJSONStr(){//已知復(fù)雜JavaBean_objTeacher teacher = JSONObject.parseObject(COMPLEX_JSON_STR, new TypeReference<Teacher>() {});String jsonString = JSONObject.toJSONString(teacher);System.out.println(jsonString);
}

2.3.javaBean與json對(duì)象間的之間的轉(zhuǎn)換
2.3.1.簡(jiǎn)單javaBean與json對(duì)象之間的轉(zhuǎn)換

/*** 簡(jiǎn)單JavaBean_obj到j(luò)son對(duì)象的轉(zhuǎn)換*/
@Test
public void testJavaBeanToJSONObject(){//已知簡(jiǎn)單JavaBean_objStudent student = new Student("lily", 12);//方式一String jsonString = JSONObject.toJSONString(student);JSONObject jsonObject = JSONObject.parseObject(jsonString);System.out.println(jsonObject);//方式二JSONObject jsonObject1 = (JSONObject) JSONObject.toJSON(student);System.out.println(jsonObject1);
}/*** 簡(jiǎn)單json對(duì)象到JavaBean_obj的轉(zhuǎn)換*/
@Test
public void testJSONObjectToJavaBean(){//已知簡(jiǎn)單json對(duì)象JSONObject jsonObject = JSONObject.parseObject(JSON_OBJ_STR);//第一種方式,使用TypeReference<T>類,由于其構(gòu)造方法使用protected進(jìn)行修飾,故創(chuàng)建其子類Student student = JSONObject.parseObject(jsonObject.toJSONString(), new TypeReference<Student>() {});System.out.println(student);//第二種方式,使用Gson的思想Student student1 = JSONObject.parseObject(jsonObject.toJSONString(), Student.class);System.out.println(student1);
}

2.3.2.JavaList與JsonArray之間的轉(zhuǎn)換

/*** JavaList到JsonArray的轉(zhuǎn)換*/
@Test
public void testJavaListToJsonArray() {//已知JavaListStudent student = new Student("lily", 12);Student studenttwo = new Student("lucy", 15);List<Student> students = new ArrayList<Student>();students.add(student);students.add(studenttwo);//方式一String jsonString = JSONArray.toJSONString(students);JSONArray jsonArray = JSONArray.parseArray(jsonString);System.out.println(jsonArray);//方式二JSONArray jsonArray1 = (JSONArray) JSONArray.toJSON(students);System.out.println(jsonArray1);
}/*** JsonArray到JavaList的轉(zhuǎn)換*/
@Test
public void testJsonArrayToJavaList() {//已知JsonArrayJSONArray jsonArray = JSONArray.parseArray(JSON_ARRAY_STR);//第一種方式,使用TypeReference<T>類,由于其構(gòu)造方法使用protected進(jìn)行修飾,故創(chuàng)建其子類ArrayList<Student> students = JSONArray.parseObject(jsonArray.toJSONString(),new TypeReference<ArrayList<Student>>() {});System.out.println(students);//第二種方式,使用Gson的思想List<Student> students1 = JSONArray.parseArray(jsonArray.toJSONString(), Student.class);System.out.println(students1);
}

2.3.3.復(fù)雜JavaBean_obj與json對(duì)象之間的轉(zhuǎn)換

/*** 復(fù)雜JavaBean_obj到j(luò)son對(duì)象的轉(zhuǎn)換*/
@Test
public void testComplexJavaBeanToJSONObject() {//已知復(fù)雜JavaBean_objStudent 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);//方式一String jsonString = JSONObject.toJSONString(teacher);JSONObject jsonObject = JSONObject.parseObject(jsonString);System.out.println(jsonObject);//方式二JSONObject jsonObject1 = (JSONObject) JSONObject.toJSON(teacher);System.out.println(jsonObject1);}/*** 復(fù)雜json對(duì)象到JavaBean_obj的轉(zhuǎn)換*/
@Test
public void testComplexJSONObjectToJavaBean() {//已知復(fù)雜json對(duì)象JSONObject jsonObject = JSONObject.parseObject(COMPLEX_JSON_STR);//第一種方式,使用TypeReference<T>類,由于其構(gòu)造方法使用protected進(jìn)行修飾,故創(chuàng)建其子類Teacher teacher = JSONObject.parseObject(jsonObject.toJSONString(), new TypeReference<Teacher>() {});System.out.println(teacher);//第二種方式,使用Gson的思想Teacher teacher1 = JSONObject.parseObject(jsonObject.toJSONString(), Teacher.class);System.out.println(teacher1);
}