📅  最后修改于: 2020-11-16 07:31:52             🧑  作者: Mango
让我们将一个Java对象序列化为一个json文件,然后读取该json文件以将该对象取回。在此示例中,我们创建了Student类。我们将创建一个student.json文件,该文件将具有Student对象的json表示形式。
在C:\> Jackson_WORKSPACE中创建一个名为JacksonTester的Java类文件。
文件:JacksonTester.java
import java.io.File;
import java.io.IOException;
import com.fasterxml.jackson.core.JsonGenerationException;
import com.fasterxml.jackson.core.JsonParseException;
import com.fasterxml.jackson.databind.JsonMappingException;
import com.fasterxml.jackson.databind.ObjectMapper;
public class JacksonTester {
public static void main(String args[]){
JacksonTester tester = new JacksonTester();
try {
Student student = new Student();
student.setAge(10);
student.setName("Mahesh");
tester.writeJSON(student);
Student student1 = tester.readJSON();
System.out.println(student1);
} catch (JsonParseException e) {
e.printStackTrace();
} catch (JsonMappingException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private void writeJSON(Student student) throws JsonGenerationException, JsonMappingException, IOException{
ObjectMapper mapper = new ObjectMapper();
mapper.writeValue(new File("student.json"), student);
}
private Student readJSON() throws JsonParseException, JsonMappingException, IOException{
ObjectMapper mapper = new ObjectMapper();
Student student = mapper.readValue(new File("student.json"), Student.class);
return student;
}
}
class Student {
private String name;
private int age;
public Student(){}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String toString(){
return "Student [ name: "+name+", age: "+ age+ " ]";
}
}
验证结果
使用javac编译器编译类,如下所示:
C:\Jackson_WORKSPACE>javac JacksonTester.java
现在运行jacksonTester以查看结果:
C:\Jackson_WORKSPACE>java JacksonTester
验证输出
Student [ name: Mahesh, age: 10 ]