Json解析工具Jackson
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@JsonIgnoreProperties
此注解是类注解,作用是json序列化时将Java bean中的一些属性忽略掉,序列化和反序列化都受影响。
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@JsonIgnore
此注解用于属性或者方法上(最好是属性上),作用和上面的@JsonIgnoreProperties一样。
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@JsonFormat
此注解用于属性或者方法上(最好是属性上),可以方便的把Date类型直接转化为我们想要的模式,比如@JsonFormat(pattern = "yyyy-MM-dd HH-mm-ss")
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@JsonSerialize
此注解用于属性或者getter方法上,用于在序列化时嵌入我们自定义的代码,比如序列化一个double时在其后面限制两位小数点。
public class CustomDoubleSerialize extends JsonSerializer<Double> {
private DecimalFormat df = new DecimalFormat("##.00");
@Override
public void serialize(Double value, JsonGenerator jgen,
SerializerProvider provider) throws IOException,
JsonProcessingException {
jgen.writeString(df.format(value));
}
}
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@JsonDeserialize
此注解用于属性或者setter方法上,用于在反序列化时可以嵌入我们自定义的代码,类似于上面的@JsonSerialize
public class CustomDateDeserialize extends JsonDeserializer<Date> {
private SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
@Override
public Date deserialize(JsonParser jp, DeserializationContext ctxt)
throws IOException, JsonProcessingException {
Date date = null;
try {
date = sdf.parse(jp.getText());
} catch (ParseException e) {
e.printStackTrace();
}
return date;
}
}
完整例子:
//表示序列化时忽略的属性
@JsonIgnoreProperties(value = { "word" })
public class Person {
private String name;
private int age;
private boolean sex;
private Date birthday;
private String word;
private double salary;
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 boolean isSex() {
return sex;
}
public void setSex(boolean sex) {
this.sex = sex;
}
public Date getBirthday() {
return birthday;
}
// 反序列化一个固定格式的Date
@JsonDeserialize(using = CustomDateDeserialize.class)
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
public String getWord() {
return word;
}
public void setWord(String word) {
this.word = word;
}
// 序列化指定格式的double格式
@JsonSerialize(using = CustomDoubleSerialize.class)
public double getSalary() {
return salary;
}
public void setSalary(double salary) {
this.salary = salary;
}
public Person(String name, int age) {
this.name = name;
this.age = age;
}
public Person(String name, int age, boolean sex, Date birthday,
String word, double salary) {
super();
this.name = name;
this.age = age;
this.sex = sex;
this.birthday = birthday;
this.word = word;
this.salary = salary;
}
public Person() {
}
@Override
public String toString() {
return "Person [name=" + name + ", age=" + age + ", sex=" + sex
+ ", birthday=" + birthday + ", word=" + word + ", salary="
+ salary + "]";
}
}
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