/**
*工具类所需jar包(其他版本也可以)
*commons-lang3-3.1.jar
*jackson-core-asl-1.9.13.jar
*jackson-mapper-asl-1.9.13.jar
*/
package com.zqvideo.util;
import java.io.IOException;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import org.apache.commons.lang.StringUtils;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.annotate.JsonSerialize.Inclusion;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Jackson的简单封装.
*
* @author calvin
*/
public class JsonBinder {
private static Logger logger = LoggerFactory.getLogger(JsonBinder.class);
private ObjectMapper mapper;
public JsonBinder(Inclusion inclusion) {
mapper = new ObjectMapper();
// 设置输出包含的属性
mapper.getSerializationConfig().setSerializationInclusion(inclusion);
// 设置输入时忽略JSON字符串中存在而Java对象实际没有的属性
mapper.getDeserializationConfig().set(org.codehaus.jackson.map.DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);
}
/**
* 创建输出全部属性到Json字符串的Binder.
*/
public static JsonBinder buildNormalBinder() {
return new JsonBinder(Inclusion.ALWAYS);
}
/**
* 创建只输出非空属性到Json字符串的Binder.
*/
public static JsonBinder buildNonNullBinder() {
return new JsonBinder(Inclusion.NON_NULL);
}
/**
* 创建只输出初始值被改变的属性到Json字符串的Binder.
*/
public static JsonBinder buildNonDefaultBinder() {
return new JsonBinder(Inclusion.NON_DEFAULT);
}
/**
* 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. 如需读取集合如List/Map,且不是List<String>这种简单类型时使用如下语句: List<MyBean>
* beanList = binder.getMapper().readValue(listString, new TypeReference<List<MyBean>>() {});
*/
public <T> T fromJson(String jsonString, Class<T> 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;
}
}
/**
* 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;
}
}
/**
* 设置转换日期类型的format pattern,如果不设置默认打印Timestamp毫秒数.
*/
public void setDateFormat(String pattern) {
if (StringUtils.isNotBlank(pattern)) {
DateFormat df = new SimpleDateFormat(pattern);
mapper.getSerializationConfig().setDateFormat(df);
mapper.getDeserializationConfig().setDateFormat(df);
}
}
/**
* 取出Mapper做进一步的设置或使用其他序列化API.
*/
public ObjectMapper getMapper() {
return mapper;
}
}
/**通过这两句即可调用此工具类*/
String result = jsonBinder.toJson(ames);