本文共 12842 字，大约阅读时间需要 42 分钟。
转载自:
1.前言 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: FastJson1.2.FastJson的特点:
1.FastJson速度快,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
import java.util.ArrayList;import java.util.List;import org.junit.Test;import com.alibaba.fastjson.JSONArray;import com.alibaba.fastjson.JSONObject;import com.alibaba.fastjson.TypeReference;public class TestFastJson { // json字符串-简单对象型 private static final String JSON_OBJ_STR = "{\"studentName\":\"lily\",\"studentAge\":12}"; // private static final String JSON_OBJ_STR2 = // "{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}]}"; /** * json字符串-简单对象型到JSONObject的转换 JSONObject.parseObject(Str) */ @Test public void testJSONStrToJSONObject() { JSONObject jsonObject = JSONObject.parseObject(JSON_OBJ_STR); System.out.println("studentName: " + jsonObject.getString("studentName") + ":" + " studentAge: " + jsonObject.getInteger("studentAge")); } /** * JSONObject到json字符串-简单对象型的转换 JSONObject.toJSONString(jsonObject) */ @Test public void testJSONObjectToJSONStr() { // 已知JSONObject,目标要转换为json字符串 JSONObject jsonObject = JSONObject.parseObject(JSON_OBJ_STR); // 第一种方式 String jsonString = JSONObject.toJSONString(jsonObject); // 第二种方式 // String jsonString = jsonObject.toJSONString(); System.out.println(jsonString); } /** * json字符串-数组类型到JSONArray的转换 JSONArray.parseArray(Str) */ @Test public void testJSONStrToJSONArray() { JSONArray jsonArray = JSONArray.parseArray(JSON_ARRAY_STR); // 遍历方式1 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")); } // 遍历方式2 for (Object obj : jsonArray) { JSONObject jsonObject = (JSONObject) obj; System.out.println("studentName: " + jsonObject.getString("studentName") + ":" + " studentAge: " + jsonObject.getInteger("studentAge")); } } /** * JSONArray到json字符串-数组类型的转换 JSONArray.toJSONString(jsonArray) */ @Test public void testJSONArrayToJSONStr() { // 已知JSONArray,目标要转换为json字符串 JSONArray jsonArray = JSONArray.parseArray(JSON_ARRAY_STR); // 第一种方式 String jsonString = JSONArray.toJSONString(jsonArray); // 第二种方式 // String jsonString = jsonArray.toJSONString(jsonArray); System.out.println(jsonString); } /** * 复杂json格式字符串到JSONObject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"); // 获取JSONObject中的数据 String courseName = jsonObjectcourse.getString("courseName"); Integer code = jsonObjectcourse.getInteger("code"); System.out.println("courseName: " + courseName + " code: " + code); JSONArray jsonArraystudents = jsonObject.getJSONArray("students"); // 遍历JSONArray 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); } } /** * 复杂JSONObject到json格式字符串的转换 */ @Test public void testJSONObjectToComplexJSONStr() { // 复杂JSONObject,目标要转换为json字符串 JSONObject jsonObject = JSONObject.parseObject(COMPLEX_JSON_STR); // 第一种方式 // String jsonString = JSONObject.toJSONString(jsonObject); // 第二种方式 String jsonString = jsonObject.toJSONString(); System.out.println(jsonString); } /** * json字符串-简单对象到JavaBean之间的转换 JSONObject.parseObject(JSON_OBJ_STR, * Student.class) */ @Test public void testJSONStrToJavaBeanObj() { // 第一种方式 JSONObject jsonObject = JSONObject.parseObject(JSON_OBJ_STR); String studentName = jsonObject.getString("studentName"); Integer studentAge = jsonObject.getInteger("studentAge"); // Student student = new Student(studentName, studentAge); // 第二种方式,使用TypeReference 类,由于其构造方法使用protected进行修饰,故创建其子类 // Student student = JSONObject.parseObject(JSON_OBJ_STR, new // TypeReference () {}); // 第三种方式,使用Gson的思想 need default constructor Student student = JSONObject.parseObject(JSON_OBJ_STR, Student.class); System.out.println(student.toString()); } /** * JavaBean到json字符串-简单对象的转换 */ @Test public void testJavaBeanObjToJSONStr() { Student student = new Student("lily", 12); String jsonString = JSONObject.toJSONString(student); System.out.println(jsonString); } /** * json字符串-数组类型到JavaBean_List的转换 */ @Test public void testJSONStrToJavaBeanList() { // 第一种方式 JSONArray jsonArray = JSONArray.parseArray(JSON_ARRAY_STR); // 遍历JSONArray List students = new ArrayList (); 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); // 第二种方式,使用TypeReference 类,由于其构造方法使用protected进行修饰,故创建其子类 List studentList = JSONArray.parseObject(JSON_ARRAY_STR, new TypeReference >() { }); System.out.println("studentList: " + studentList); // 第三种方式,使用Gson的思想 List studentList1 = JSONArray.parseArray(JSON_ARRAY_STR, Student.class); System.out.println("studentList1: " + studentList1); } /** * JavaBean_List到json字符串-数组类型的转换 */ @Test public void testJavaBeanListToJSONStr() { Student student = new Student("lily", 12); Student studenttwo = new Student("lucy", 15); List students = new ArrayList (); students.add(student); students.add(studenttwo); String jsonString = JSONArray.toJSONString(students); System.out.println(jsonString); } /** * 复杂json格式字符串到JavaBean_obj的转换 */ @Test public void testComplexJSONStrToJavaBean() { // 第一种方式,使用TypeReference 类,由于其构造方法使用protected进行修饰,故创建其子类 Teacher teacher = JSONObject.parseObject(COMPLEX_JSON_STR, new TypeReference () { }); System.out.println(teacher); // 第二种方式,使用Gson思想 Teacher teacher1 = JSONObject.parseObject(COMPLEX_JSON_STR, Teacher.class); System.out.println(teacher1); } /** * 复杂JavaBean_obj到json格式字符串的转换 */ @Test public void testJavaBeanToComplexJSONStr() { // 已知复杂JavaBean_obj Teacher teacher = JSONObject.parseObject(COMPLEX_JSON_STR, new TypeReference () { }); String jsonString = JSONObject.toJSONString(teacher); System.out.println(jsonString); } /** * 简单JavaBean_obj到json对象的转换 */ @Test public void testJavaBeanToJSONObject() { // 已知简单JavaBean_obj Student 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); } /** * 简单json对象到JavaBean_obj的转换 */ @Test public void testJSONObjectToJavaBean() { // 已知简单json对象 JSONObject jsonObject = JSONObject.parseObject(JSON_OBJ_STR); // 第一种方式,使用TypeReference 类,由于其构造方法使用protected进行修饰,故创建其子类 Student student = JSONObject.parseObject(jsonObject.toJSONString(), new TypeReference () { }); System.out.println(student); // 第二种方式,使用Gson的思想 Student student1 = JSONObject.parseObject(jsonObject.toJSONString(), Student.class); System.out.println(student1); } /** * JavaList到JsonArray的转换 */ @Test public void testJavaListToJsonArray() { // 已知JavaList Student student = new Student("lily", 12); Student studenttwo = new Student("lucy", 15); List students = new ArrayList (); 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的转换 */ @Test public void testJsonArrayToJavaList() { // 已知JsonArray JSONArray jsonArray = JSONArray.parseArray(JSON_ARRAY_STR); // 第一种方式,使用TypeReference 类,由于其构造方法使用protected进行修饰,故创建其子类 ArrayList students = JSONArray.parseObject(jsonArray.toJSONString(), new TypeReference >() { }); System.out.println(students); // 第二种方式,使用Gson的思想 List students1 = JSONArray.parseArray(jsonArray.toJSONString(), Student.class); System.out.println(students1); } /** * 复杂JavaBean_obj到json对象的转换 */ @Test public void testComplexJavaBeanToJSONObject() { // 已知复杂JavaBean_obj Student student = new Student("lily", 12); Student studenttwo = new Student("lucy", 15); List students = new ArrayList (); 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); } /** * 复杂json对象到JavaBean_obj的转换 */ @Test public void testComplexJSONObjectToJavaBean() { // 已知复杂json对象 JSONObject jsonObject = JSONObject.parseObject(COMPLEX_JSON_STR); // 第一种方式,使用TypeReference 类,由于其构造方法使用protected进行修饰,故创建其子类 Teacher teacher = JSONObject.parseObject(jsonObject.toJSONString(), new TypeReference () { }); System.out.println(teacher); // 第二种方式,使用Gson的思想 Teacher teacher1 = JSONObject.parseObject(jsonObject.toJSONString(), Teacher.class); System.out.println(teacher1); }}/** * @author Zhangdi class Student */class Student { private String studentName; private Integer studentAge; protected Student() { super(); } protected Student(String studentName, Integer studentAge) { super(); this.studentName = studentName; this.studentAge = 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; } @Override public String toString() { return "Student [studentName=" + studentName + ", studentAge=" + studentAge + "]"; }}/** * @author Zhangdi Teacher */class Teacher { private String teacherName; private Integer teacherAge; private Course course; private List students; protected Teacher() { super(); // TODO Auto-generated constructor stub } protected Teacher(String teacherName, Integer teacherAge) { super(); this.teacherName = teacherName; this.teacherAge = teacherAge; } public Teacher(String teacherName, int teacherAge, Course course, List students) { this.teacherName = teacherName; this.teacherAge = teacherAge; this.course = course; this.students = 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; } @Override public String toString() { return "Teacher [teacherName=" + teacherName + ", teacherAge=" + teacherAge + "]"; }}class Course{ private String courseName; private Integer code; protected Course() { super(); } protected Course(String courseName, Integer code) { super(); this.courseName = courseName; this.code = 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 static String getArrJson() { JSONObject jsonObject = new JSONObject(); List