1. User object
package com.st.json; import java.util.Date; /** * @Description: User class used for JSON serialization and deserialization * @author Mr.Li *@date April 21, 2018 at 10:55:34 PM */ public class User { private Integer id; private String name; private Integer age; private Date birthday; private String email; public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public Integer getAge() { return age; } public void setAge(Integer age) { this.age = age; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } public String getEmail() { return email; } public void setEmail(String email) { this.email = email; } @Override public String toString() { return "User [id=" + id + ", name=" + name + ", age=" + age + ", birthday=" + birthday + ", email=" + email + "]"; } public User(Integer id, String name, Integer age, Date birthday, String email) { super(); this.id = id; this.name = name; this.age = age; this.birthday = birthday; this.email = email; } public User() { super(); // TODO Auto-generated constructor stub } }
2, JacksonUtil tool class
package com.st.json; import java.io.IOException; import java.io.StringWriter; import com.fasterxml.jackson.core.JsonFactory; import com.fasterxml.jackson.core.JsonGenerator; import com.fasterxml.jackson.core.JsonParseException; import com.fasterxml.jackson.databind.JsonMappingException; import com.fasterxml.jackson.databind.ObjectMapper; /** * @Description: Jackson object and json conversion tool class * @author Mr.Li *@date April 22, 2018 at 12:30:15 AM */ public class JacksonUtil { private static ObjectMapper mapper = new ObjectMapper(); public static String BeanToJson(Object obj) throws IOException { StringWriter sw = new StringWriter(); JsonGenerator gen = new JsonFactory().createGenerator(sw); mapper.writeValue(gen, obj); gen.close(); return sw.toString(); } public static <T> T JsonToBean(String jsonStr, Class<T> objClass) throws JsonParseException, JsonMappingException, IOException { return mapper.readValue(jsonStr, objClass); } }
3, Jackson object and json conversion test
package com.st.json; import java.io.IOException; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.List; import com.fasterxml.jackson.core.JsonParseException; import com.fasterxml.jackson.databind.JsonMappingException; /** * @Description: Jackson object and json conversion test * @author Mr.Li *@date April 22, 2018 12:39:39 AM */ public class JacksonUtilTest { public static void main(String[] args) throws ParseException, IOException { beanTojack(); // jsonTobean(); } public static void beanTojack() throws ParseException, IOException { User u = new User(); u.setId ( 1 ); u.setName("curry"); u.setAge(30); SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd"); u.setBirthday(dateFormat.parse("1988-9-21")); u.setEmail("[email protected]"); User u2 = new User(); u2.setId( 2 ); u2.setName("KD"); u2.setAge(29); u2.setBirthday(dateFormat.parse("1989-9-21")); u2.setEmail("[email protected]"); List<User> users = new ArrayList<>(); users.add(u); users.add(u2); // Object to json format String beanToJson = JacksonUtil.BeanToJson(users); System.out.println(beanToJson); } public static void jsonTobean() throws JsonParseException, JsonMappingException, IOException { String json = " {\"id\":3, \"name\":\"小明\", \"age\":18, \"birthday\":590774400000, \"email\":\"[email protected]\"} "; User jsonToBean = JacksonUtil.JsonToBean(json, User.class); System.out.println(jsonToBean); } }