Json字符串与Object、List、Map的互转工具类

package com.cq2022.zago. .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. Mapper;
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  Mapper  Mapper = new  Mapper();
 private static JsonFactory jsonFactory = new JsonFactory();
 static {
  Mapper.configure(SerializationConfig.Feature.WRITE_NULL_MAP_VALUES, false);
  Mapper.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  Mapper.readValue(jsonAsString, pojoClass);
 }
 public static <T> T fromJson(FileReader fr, Class<T> pojoClass) throws JsonParseException, IOException {
 return  Mapper.readValue(fr, pojoClass);
 }
 /**
 *  对象转json
 * @param pojo
 * @return
 * @throws JsonMappingException
 * @throws JsonGenerationException
 * @throws IOException
 */
 public static String toJson(  pojo) throws JsonMappingException, JsonGenerationException, IOException {
 return toJson(pojo, false);
 }
 public static String toJson(  pojo, boolean prettyPrint) throws JsonMappingException, JsonGenerationException,
  IOException {
 StringWriter sw = new StringWriter();
 JsonGenerator jg = jsonFactory.createJsonGenerator(sw);
 if (prettyPrint) {
  jg.useDefaultPrettyPrinter();
 }
  Mapper.writeValue(jg, pojo);
 return sw.toString();
 }
 public static void toJson(  pojo, FileWriter fw, boolean prettyPrint) throws JsonMappingException,
  JsonGenerationException, IOException {
 JsonGenerator jg = jsonFactory.createJsonGenerator(fw);
 if (prettyPrint) {
  jg.useDefaultPrettyPrinter();
 }
  Mapper.writeValue(jg, pojo);
 }
 /**
 * json字符串转Map
 * @param jsonStr
 * @return
 * @throws IOException
 */
 public static Map<String,  > parseMap(String jsonStr) throws IOException {
 Map<String,  > map =  Mapper.readValue(jsonStr, Map.class);
 return map;
 }
 public static JsonNode parse(String jsonStr) throws IOException {
 JsonNode node = null;
 node =  Mapper.readTree(jsonStr);
 return node;
 }
 public static  Mapper get Mapper() {
 return  Mapper;
 }
 /**
 * 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);
 }
}