Java中Gson的fromJson()和toJson()方法之间的区别？
甲GSON 是为Java库，它可以被用来产生一个JSON。我们可以使用Gson 的fromJson() 方法将JSON字符串解析为java对象，并使用Gson的toJson() 方法将Java对象转换为JSONstring。fromJson()方法中有两个参数，第一个参数是我们要解析的JSONString，第二个参数是要解析JSON字符串的Java类。我们可以将一个参数传递给toJson() 方法，该方法是我们要转换为JSON字符串的Java对象。
的语法fromJson()
public <T> fromJson(java.lang.String json, java.lang.Class<T> classOfT) throws JsonSyntaxException
示例
import com.google.gson.*;
public class FromJsonMethodTest {
public static void main(String[] args) {
String jsonString = "{'id':101, 'firstName':'Jai','lastName':'Adithya'}";
Gson gson = new Gson();
Employee emp = gson.fromJson(jsonString, Employee.class);
System.out.println(emp);
}
}
// Employee classclass Employee {
private int id;
private String firstName;
private String lastName;
public Employee() {}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
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;
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("Id : " + id);
sb.append(", FirstName : " + firstName);
sb.append(", Last Name : " + lastName);
return sb.toString();
}
}输出结果
Id : 101, FirstName : Jai, Last Name : Adithya
的语法toJson()
public java.lang.String toJson(java.lang.Object src)
示例
import com.google.gson.*;
public class ToJsonMethodTest {
public static void main(String[] args) {
Employee emp = new Employee();
emp.setId(110);
emp.setFirstName("Raja");
emp.setLastName("Ramesh");
Gson gson = new Gson();
String jsonString = gson.toJson(emp);
System.out.println(jsonString);
}
}
// Employee classclass Employee {
private int id;
private String firstName;
private String lastName;
public Employee() {}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
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;
}
}输出结果
{"id":110,"firstName":"Raja","lastName":"Ramesh"}