Json字符串与Object、List、Map的互转工具类

package com.cq2022.zago.base.util;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.StringWriter;
import java.util.List;
import java.util.Map;
import org.codehaus.jackson.JsonFactory;
import org.codehaus.jackson.JsonGenerationException;
import org.codehaus.jackson.JsonGenerator;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.JsonParseException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.SerializationConfig;
import org.codehaus.jackson.map.annotate.JsonSerialize;
import com.alibaba.fastjson.JSONArray;
/**
* Json工具类，实现JSON与Java Bean的互相转换
*/
public class JsonUtils {
private static ObjectMapper objectMapper = new ObjectMapper();
private static JsonFactory jsonFactory = new JsonFactory();
static {
objectMapper.configure(SerializationConfig.Feature.WRITE_NULL_MAP_VALUES, false);
objectMapper.setSerializationInclusion(JsonSerialize.Inclusion.NON_NULL);
}
/**
* 泛型返回，json字符串转对象
* @param jsonAsString
* @param pojoClass
* @return
* @throws JsonMappingException
* @throws JsonParseException
* @throws IOException
*/
public static <T> T fromJson(String jsonAsString, Class<T> pojoClass) throws JsonMappingException,
 JsonParseException, IOException {
return objectMapper.readValue(jsonAsString, pojoClass);
}
public static <T> T fromJson(FileReader fr, Class<T> pojoClass) throws JsonParseException, IOException {
return objectMapper.readValue(fr, pojoClass);
}
/**
* Object对象转json
* @param pojo
* @return
* @throws JsonMappingException
* @throws JsonGenerationException
* @throws IOException
*/
public static String toJson(Object pojo) throws JsonMappingException, JsonGenerationException, IOException {
return toJson(pojo, false);
}
public static String toJson(Object pojo, boolean prettyPrint) throws JsonMappingException, JsonGenerationException,
 IOException {
StringWriter sw = new StringWriter();
JsonGenerator jg = jsonFactory.createJsonGenerator(sw);
if (prettyPrint) {
 jg.useDefaultPrettyPrinter();
}
objectMapper.writeValue(jg, pojo);
return sw.toString();
}
public static void toJson(Object pojo, FileWriter fw, boolean prettyPrint) throws JsonMappingException,
 JsonGenerationException, IOException {
JsonGenerator jg = jsonFactory.createJsonGenerator(fw);
if (prettyPrint) {
 jg.useDefaultPrettyPrinter();
}
objectMapper.writeValue(jg, pojo);
}
/**
* json字符串转Map
* @param jsonStr
* @return
* @throws IOException
*/
public static Map<String, Object> parseMap(String jsonStr) throws IOException {
Map<String, Object> map = objectMapper.readValue(jsonStr, Map.class);
return map;
}
public static JsonNode parse(String jsonStr) throws IOException {
JsonNode node = null;
node = objectMapper.readTree(jsonStr);
return node;
}
public static ObjectMapper getObjectMapper() {
return objectMapper;
}
/**
* json字符串转 List对象
* @param str json字符串
* @param clazz 转换的类型
* @return
*/
public static <T> List<T> fromListJson(String str,Class<T> clazz){
return JSONArray.parseArray(str, clazz);
}
}

来源：https://blog.csdn.net/moneyshi/article/details/44852343