Jackson解析封装

package com.inetgoes.fangdd.util;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.inetgoes.fangdd.model.BrokerResponse;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Map;

/**
* jackson解析封装
* Created by czz on 2015/11/4.
*/
public class JacksonMapper {
private static final ObjectMapper mapper = new ObjectMapper();
private static JacksonMapper jacksonMapper = null;

private JacksonMapper() {
mapper.setVisibility(PropertyAccessor.FIELD, JsonAutoDetect.Visibility.ANY);
mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES,false);
}

public static JacksonMapper getInstance() {
if (jacksonMapper == null) {
synchronized (JacksonMapper.class) {
if (jacksonMapper == null) {
jacksonMapper = new JacksonMapper();
}
}
}
return jacksonMapper;
}

public static ObjectMapper getObjectMapper() {
return mapper;
}

/**
* 解析单一的值
*
* @param json
* @param fileName
* @return
*/
public String onlyTNode(String json, String fileName) {
try {
JsonNode jsonNode = mapper.readTree(json);
return jsonNode.get(fileName).toString();
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

/**
* 以键值对Map集合解析
*
* @param json
* @return
*/
public Map<String, String> mapFromJson(String json) {
try {
Map<String, String> map = mapper.readValue(json, Map.class);
return map;
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

/**
* 以键值对Map集合解析
*
* @param json
* @return
*/
public Map<String, Object> mapObjFromJson(String json) {
try {
Map<String, Object> map = mapper.readValue(json, Map.class);
return map;
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

/**
* 以对象解析
*
* @param json
* @param c
* @param <T>
* @return
*/
public <T> T fromJson(String json, Collection<T> c) {
try {
return (T) mapper.readValue(json, c.getClass());
} catch (IOException e) {
e.printStackTrace();
}
return null;
}

/**
* 获取泛型的Collection Type
*
* @param collectionClass 泛型的Collection
* @param elementClasses  元素类
* @return JavaType Java类型
* @since 1.0
*/
public static JavaType getCollectionType(Class<?> collectionClass, Class<?>... elementClasses) {
return mapper.getTypeFactory().constructParametricType(collectionClass, elementClasses);
}

}

</pre><pre name="code" class="java"><pre name="code" class="java">使用：

map集合解析--

<pre name="code" class="java">Map<String, Object> resMap = JacksonMapper.getInstance().mapObjFromJson(result);

<pre name="code" class="java">JavaType javaType = JacksonMapper.getCollectionType(ArrayList.class, BrokerResponse.class);
List<BrokerResponse> temps = JacksonMapper.getObjectMapper().readValue(result, javaType);

</pre><pre name="code" class="java">Bean解析--

<pre name="code" class="java">userInfo = JacksonMapper.getObjectMapper().readValue(result, UserInfo.class);