如何在 Java 中使用 Gson 庫將 JSON 字串寫入檔案?
Gson 是一款庫,可用於將 Java 物件轉換為 JSON 表示。要使用的主要類是Gson ,可以透過呼叫new Gson()建立,而GsonBuilder 類可用於建立 Gson 例項。
我們可以在下面的示例中使用Gson 類的toJson()方法將 JSON 字串寫入檔案
示例
import java.io.*; import com.google.gson.*; public class JSONToFileTest { public static void main(String[] args) throws IOException { Gson gson = new Gson(); FileWriter fileWriter = new FileWriter("Student.json"); Student student = new Student("Raja", "Ramesh", 30, "Hyderabad"); gson.toJson(student, fileWriter); fileWriter.close(); System.out.println("JSON string write to a file successfully"); System.out.println(student); } } // Student class class Student { private String firstName; private String lastName; private int age; private String address; public Student(String firstName, String lastName, int age, String address) { super(); this.firstName = firstName; this.lastName = lastName; this.age = age; this.address = address; } public String getFirstName() { return firstName; } public void setFirstName(String firstName) { this.firstName = firstName; } public String getLastName() { return lastName; } public void setLastName(String lastName) { this.lastName = lastName; } public int getAge() { return age; } public void setAge(int age) { this.age = age; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } public String toString() { return "Student[ " + "firstName = " + firstName + ", lastName = " + lastName + ", age = " + age + ", address = " + address + " ]"; } }
Student.json 檔案
輸出
JSON string write to a file successfully Student[ firstName = Raja, lastName = Ramesh, age = 30, address = Hyderabad ]
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