json字符串与Object、List、Map的互转工具类，json工具类,import java.

json字符串与Object、List、Map的互转工具类，json工具类,import java.

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  * User: shijing  * <span style="font-family: Arial, Helvetica, sans-serif;">2015年4月3日上午10:42:19</span>  */  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      * 2015年4月3日上午10:42:19      * auther:shijing      * @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      * 2015年4月3日上午10:41:53      * auther:shijing      * @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      * 2015年4月3日上午10:41:25      * auther:shijing      * @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      * 2015年4月2日上午10:22:20      * auther:shijing      * @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);      }  }