json字符串與Object、List、Map的互轉工具類

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工具類，實現JSON與Java Bean的互相轉換 
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字符串轉對象 
 * 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對象轉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字符串轉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字符串轉 List對象 
 * 2015年4月2日上午10:22:20 
 * auther:shijing 
 * @param str   json字符串 
 * @param clazz 轉換的類型 
 * @return 
 */  
public static <T> List<T> fromListJson(String str,Class<T> clazz){  
    return JSONArray.parseArray(str, clazz);  
}  


}  </pre>