com.github.df.restypass.util.JsonTools Maven / Gradle / Ivy
package com.github.df.restypass.util;
import com.fasterxml.jackson.annotation.JsonInclude;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.core.JsonParser;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.core.type.TypeReference;
import com.fasterxml.jackson.databind.*;
import com.fasterxml.jackson.databind.module.SimpleModule;
import com.fasterxml.jackson.databind.util.JSONPObject;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
import java.text.ParseException;
import java.util.Collection;
import java.util.Date;
import java.util.Map;
/**
* JsonTools
* copy from spring side < calvin >
* author: fuliang
* date: 2017/3/29
*/
@SuppressWarnings("unused")
public class JsonTools {
private static Logger logger = LoggerFactory.getLogger(JsonTools.class);
private static String SIMPLE_FORMAT = "yyyy-MM-dd HH:mm:ss";
public static final JsonTools INSTANCE = new JsonTools();
private ObjectMapper mapper;
public JsonTools() {
this(null);
}
public JsonTools(JsonInclude.Include include) {
mapper = new ObjectMapper();
// 设置输出时包含属性的风格
if (include != null) {
mapper.setSerializationInclusion(include);
}
// 设置输入时忽略在JSON字符串中存在但Java对象实际没有的属性
mapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
SimpleModule javaTimeModule = new SimpleModule();
javaTimeModule.addSerializer(Date.class, new JsonDateSerializer());
javaTimeModule.addDeserializer(Date.class, new JsonDateDeserializer());
mapper.registerModule(javaTimeModule);
}
/**
* Date序列化
*/
public static class JsonDateSerializer extends JsonSerializer {
@Override
public void serialize(Date date, JsonGenerator gen, SerializerProvider serializers) throws IOException, JsonProcessingException {
String formattedDate = DateFormatTools.formatDate(SIMPLE_FORMAT, date);
gen.writeString(formattedDate);
}
}
/**
* Date反序列化
*/
public static class JsonDateDeserializer extends JsonDeserializer {
@Override
public Date deserialize(JsonParser jp, DeserializationContext ctxt) throws IOException, JsonProcessingException {
if (StringUtils.isEmpty(jp.getText())) {
return null;
}
try {
return DateFormatTools.pareDate(SIMPLE_FORMAT, jp.getText());
} catch (ParseException e) {
throw new IOException(e.getMessage());
}
}
}
/**
* 创建只输出非Null的属性到Json字符串的Mapper.
*/
public static JsonTools nonNullMapper() {
return new JsonTools(JsonInclude.Include.NON_NULL);
}
/**
* 创建只输出非Null且非Empty(如List.isEmpty)的属性到Json字符串的Mapper.
*
* 注意，要小心使用, 特别留意empty的情况.
*/
public static JsonTools nonEmptyMapper() {
return new JsonTools(JsonInclude.Include.NON_EMPTY);
}
/**
* 默认的全部输出的Mapper, 区别于INSTANCE，可以做进一步的配置
*/
public static JsonTools defaultMapper() {
return new JsonTools();
}
/**
* Object可以是POJO，也可以是Collection或数组。 如果对象为Null, 返回"null". 如果集合为空集合, 返回"[]".
*/
public String toJson(Object object) {
try {
return mapper.writeValueAsString(object);
} catch (IOException e) {
logger.warn("write to json string error:" + object, e);
return null;
}
}
/**
* 反序列化POJO或简单Collection如List.
*
* 如果JSON字符串为Null或"null"字符串, 返回Null. 如果JSON字符串为"[]", 返回空集合.
*
* 如需反序列化复杂Collection如List, 请使用fromJson(String, JavaType)
*
* @see #fromJson(String, JavaType)
*/
public T fromJson(String jsonString, Class clazz) {
if (StringUtils.isEmpty(jsonString)) {
return null;
}
try {
return mapper.readValue(jsonString, clazz);
} catch (IOException e) {
logger.warn("parse json string error:" + jsonString, e);
return null;
}
}
/**
* 反序列化复杂Collection如List, contructCollectionType()或contructMapType()构造类型, 然后调用本函数.
*/
public T fromJson(String jsonString, TypeReference typeReference) {
if (StringUtils.isEmpty(jsonString)) {
return null;
}
try {
return (T) mapper.readValue(jsonString, typeReference);
} catch (IOException e) {
logger.warn("parse json string error:" + jsonString, e);
return null;
}
}
/**
* 反序列化复杂Collection如List, contructCollectionType()或contructMapType()构造类型, 然后调用本函数.
*/
public T fromJson(String jsonString, JavaType javaType) {
if (StringUtils.isEmpty(jsonString)) {
return null;
}
try {
return (T) mapper.readValue(jsonString, javaType);
} catch (IOException e) {
logger.warn("parse json string error:" + jsonString, e);
return null;
}
}
/**
* 构造Collection类型.
*/
public JavaType buildCollectionType(Class collectionClass, Class elementClass) {
return mapper.getTypeFactory().constructCollectionType(collectionClass, elementClass);
}
/**
* 构造Map类型.
*/
public JavaType buildMapType(Class mapClass, Class keyClass, Class valueClass) {
return mapper.getTypeFactory().constructMapType(mapClass, keyClass, valueClass);
}
/**
* 当JSON里只含有Bean的部分属性時，更新一個已存在Bean，只覆盖該部分的属性.
*/
public void update(String jsonString, Object object) {
try {
mapper.readerForUpdating(object).readValue(jsonString);
} catch (JsonProcessingException e) {
logger.warn("update json string:" + jsonString + " to object:" + object + " error.", e);
} catch (IOException e) {
logger.warn("update json string:" + jsonString + " to object:" + object + " error.", e);
}
}
/**
* 輸出JSONP格式數據.
*/
public String toJsonP(String functionName, Object object) {
return toJson(new JSONPObject(functionName, object));
}
/**
* 設定是否使用Enum的toString函數來讀寫Enum, 為False時時使用Enum的name()函數來讀寫Enum, 默認為False. 注意本函數一定要在Mapper創建後, 所有的讀寫動作之前調用.
*/
public void enableEnumUseToString() {
mapper.enable(SerializationFeature.WRITE_ENUMS_USING_TO_STRING);
mapper.enable(DeserializationFeature.READ_ENUMS_USING_TO_STRING);
}
/**
* 取出Mapper做进一步的设置或使用其他序列化API.
*/
public ObjectMapper getMapper() {
return mapper;
}
}