jackson 完整Jar包

import java.io.StringWriter;  
import java.util.ArrayList;  
import java.util.HashMap;  
import java.util.List;  
import java.util.Map;  
  
import org.codehaus.jackson.JsonFactory;  
import org.codehaus.jackson.JsonGenerator;  
import org.codehaus.jackson.JsonParser;  
import org.codehaus.jackson.map.DeserializationConfig.Feature;  
import org.codehaus.jackson.map.MappingJsonFactory;  
import org.codehaus.jackson.map.ObjectMapper;  
import org.codehaus.jackson.type.JavaType;  
  
public class JsonUtils {  
  
    public static <K, V> String toJson(Map<K, V> obj) {  
        String jsonString = "";  
        try {  
            if (obj == null) {  
                return "";  
            }  
            StringWriter sw = new StringWriter();  
            JsonGenerator gen = new JsonFactory().createJsonGenerator(sw);  
            ObjectMapper mapper = new ObjectMapper();  
            mapper.writeValue(gen, obj);  
            jsonString = sw.toString();  
            sw.close();  
        } catch (Exception ex) {  
            ex.printStackTrace();  
            return "";  
        }  
  
        return jsonString;  
    }  
  
    @SuppressWarnings("unchecked")  
    public static Map<String, Object> toMap(String json) {  
        Map<String, Object> result = new HashMap<String, Object>();  
        try {  
            if (json == null || json.equals("")) {  
                return null;  
            }  
  
            ObjectMapper objectMapper = new ObjectMapper();  
            result = objectMapper.readValue(json, Map.class);  
            if (result == null) {  
                return new HashMap<String, Object>();  
            }  
        } catch (Exception ex) {  
            ex.printStackTrace();  
        }  
  
        return result;  
    }  
  
    public static String toJson(Object object) {  
        String json = "";  
        try {  
            if (object == null) {  
                return "";  
            }  
            StringWriter sw = new StringWriter();  
            JsonGenerator gen = new JsonFactory().createJsonGenerator(sw);  
            ObjectMapper mapper = new ObjectMapper();  
  
            mapper.writeValue(gen, object);  
  
            json = sw.toString();  
            sw.close();  
        } catch (Exception ex) {  
            ex.printStackTrace();  
            json = "";  
        }  
        return json;  
    }  
  
    public static <T> T toObject(String json, Class<T> clazz) {  
        T obj = null;  
        try {  
            if (json == null || json.equals("")) {  
                return null;  
            }  
            JsonFactory jsonFactory = new MappingJsonFactory();  
            JsonParser jsonParser = jsonFactory.createJsonParser(json);  
            ObjectMapper mapper = new ObjectMapper();  
    mapper.configure(Feature.FAIL_ON_UNKNOWN_PROPERTIES,false);
            //mapper.getDeserializationConfig().set(Feature.FAIL_ON_UNKNOWN_PROPERTIES, false);  
            obj = mapper.readValue(jsonParser, clazz);  
  
        } catch (Exception ex) {  
            ex.printStackTrace();  
            obj = null;  
        }  
        return obj;  
  
    }  
  
    public static <T> List<T> toList(String json, Class<T> clazz) {  
        if (json == null || json.equals("")) {  
            return null;  
        }  
        ObjectMapper mapper = new ObjectMapper();  
        mapper.configure(Feature.FAIL_ON_UNKNOWN_PROPERTIES,false); 
        List<T> list = new ArrayList<T>();  
        try {  
            JavaType type = mapper.getTypeFactory().constructParametricType(List.class, clazz);  
            list = mapper.readValue(json, type);  
            return list;  
        } catch (Exception e) {  
            e.printStackTrace();  
        }  
  
        return list;  
    }  
}