JSON转对象关键语法:gson.fromJson 对象转JSON关键语法:gson.toJson ================================================================================================================ 1、第一种,比如json字符串为:[{"name":"name0","age":0}] 代码: Person person = gson.fromJson(str, Person.class); ================================================================================================================ 2、第二种,转换成列表类型:[{"name":"name0","age":0},{"name":"name1","age":5}] 代码: List<Person> ps = gson.fromJson(str, new TypeToken<List<Person>>(){}.getType()); for(int i = 0; i < ps.size() ; i++) { Person p = ps.get(i); System.out.println(p.toString()); } 可以看到上面的代码使用了TypeToken,它是gson提供的数据类型转换器,可以支持各种数据集合类型转换。 ================================================================================================================ Convert numbers array into JSON string.(number数组转json字符串) int[] numbers = {1, 1, 2, 3, 5, 8, 13}; Gson gson = new Gson(); String numbersJson = gson.toJson(numbers); System.out.println("numbersJson = " + numbersJson); ================================================================================================================ Convert strings array into JSON string(string数组转json字符串) String[] days = {"Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"}; String daysJson = gson.toJson(days); System.out.println("daysJson = " + daysJson); ================================================================================================================ Convert from JSON string to a primitive array of int.(从JSON字符串转换为原始数组int。) int[] fibonacci = gson.fromJson(numbersJson, int[].class); for (int i = 0; i < fibonacci.length; i++) { System.out.print(fibonacci[i] + " "); } System.out.println(""); ================================================================================================================ Convert from JSON string to a string array.(从JSON字符串转换为一个字符串数组。) String[] weekDays = gson.fromJson(daysJson, String[].class); for (int i = 0; i < weekDays.length; i++) { System.out.print(weekDays[i] + " "); } System.out.println(""); ================================================================================================================ Converting multidimensional array into JSON(多维数组转换成JSON) int[][] data = {{1, 2, 3}, {3, 4, 5}, {4, 5, 6}}; String json = gson.toJson(data); System.out.println("Data = " + json); // // Convert JSON string into multidimensional array of int. // int[][] dataMap = gson.fromJson(json, int[][].class); for (int i = 0; i < data.length; i++) { for (int j = 0; j < data[i].length; j++) { System.out.print(data[i][j] + " "); } System.out.println(""); } ================================================================================================================ Converts a collection of string object into JSON string.(转换成JSON字符串集的字符串对象。) List<String> names = new ArrayList<String>(); names.add("Alice"); names.add("Bob"); names.add("Carol"); names.add("Mallory"); Gson gson = new Gson(); String jsonNames = gson.toJson(names); System.out.println("jsonNames = " + jsonNames); ================================================================================================================ Converts a collection Student object into JSON string(将收集的学生对象转换成JSON字符串) Student a = new Student("Alice", "Apple St", new Date(2000, 10, 1)); Student b = new Student("Bob", "Banana St", null); Student c = new Student("Carol", "Grape St", new Date(2000, 5, 21)); Student d = new Student("Mallory", "Mango St", null); List<Student> students = new ArrayList<Student>(); students.add(a); students.add(b); students.add(c); students.add(d); Gson gson = new Gson(); String jsonStudents = gson.toJson(students); System.out.println("jsonStudents = " + jsonStudents); ================================================================================================================ Converts JSON string into a collection of Student object.(将JSON字符串为一个Student对象。) Type type = new TypeToken<List<Student>>(){}.getType(); List<Student> studentList = gson.fromJson(jsonStudents, type); for (Student student : studentList) { System.out.println("student.getName() = " + student.getName()); } ================================================================================================================ json 串转化成 Java对象。() String json = "{\"name\":\"Duke\",\"address\":\"Menlo Park\",\"dateOfBirth\":\"Feb 1, 2000 12:00:00 AM\"}"; Gson gson = new Gson(); Student student = gson.fromJson(json, Student.class); System.out.println("student.getName() = " + student.getName()); System.out.println("student.getAddress() = " + student.getAddress()); System.out.println("student.getDateOfBirth() = " + student.getDateOfBirth()); ================================================================================================================ Gson处理一个对象的某一字段。() Calendar dob = Calendar.getInstance(); dob.set(1980, 10, 11); People people = new People("John", "350 Banana St.", dob.getTime()); people.setSecret("This is a secret!"); Gson gson = new Gson(); String json = gson.toJson(people); System.out.println("json = " + json); 输出结果:json = {"name":"John","address":"350 Banana St.","dateOfBirth":"Nov 11, 1980 8:47:04 AM"} 实体类 public class People { private String name; private String address; private Date dateOfBirth; private Integer age; private transient String secret; public People(String name, String address, Date dateOfBirth) { this.name = name; this.address = address; this.dateOfBirth = dateOfBirth; } public String getSecret() { return secret; } public void setSecret(String secret) { this.secret = secret; } }