JackJson的一些方法

package cn.edu.hbcf.common.jackjson;

import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Set;

import org.codehaus.jackson.JsonGenerationException;
import org.codehaus.jackson.JsonParseException;
import org.codehaus.jackson.map.JsonMappingException;
import org.codehaus.jackson.map.ObjectMapper;
import org.codehaus.jackson.map.ser.FilterProvider;
import org.codehaus.jackson.map.ser.impl.SimpleBeanPropertyFilter;
import org.codehaus.jackson.map.ser.impl.SimpleFilterProvider;
import org.codehaus.jackson.type.JavaType;
import org.codehaus.jackson.type.TypeReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
* jackjson的一些转换方法
*
*/
public class JackJson {
private static final Logger logger = LoggerFactory.getLogger(JackJson.class);
/** 格式化时间的string */
private static final String DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss";

/**
* jackjson把json字符串转换为Java对象的实现方法
*
* <pre>
* return JackJson.fromJsonToObject(this.answersJson, new TypeReference<List<StanzaAnswer>>() {
* });
* </pre>
*
* @param <T>
*            转换为的java对象
* @param json
*            json字符串
* @param typeReference
*            jackjson自定义的类型
* @return 返回Java对象
*/
public static <T> T fromJsonToObject(String json, TypeReference<T> typeReference) {
ObjectMapper mapper = new ObjectMapper();
try {
return (T)mapper.readValue(json, typeReference);
} catch (JsonParseException e) {
logger.error("JsonParseException: ", e);
} catch (JsonMappingException e) {
logger.error("JsonMappingException: ", e);
} catch (IOException e) {
logger.error("IOException: ", e);
}
return null;
}

/**
* json转换为java对象
*
* <pre>
* return JackJson.fromJsonToObject(this.answersJson, JackJson.class);
* </pre>
*
* @param <T>
*            要转换的对象
* @param json
*            字符串
* @param valueType
*            对象的class
* @return 返回对象
*/
public static <T> T fromJsonToObject(String json, Class<T> valueType) {
ObjectMapper mapper = new ObjectMapper();
try {
return (T)mapper.readValue(json, valueType);
} catch (JsonParseException e) {
logger.error("JsonParseException: ", e);
} catch (JsonMappingException e) {
logger.error("JsonMappingException: ", e);
} catch (IOException e) {
logger.error("IOException: ", e);
}
return null;
}

/**
* java对象转换为json字符串
*
* @param object
*            Java对象
* @return 返回字符串
*/
public static String fromObjectToJson(Object object) {
ObjectMapper mapper = new ObjectMapper();
try {
return mapper.writeValueAsString(object);
} catch (JsonGenerationException e) {
logger.error("JsonGenerationException: ", e);
} catch (JsonMappingException e) {
logger.error("JsonMappingException: ", e);
} catch (IOException e) {
logger.error("IOException: ", e);
}
return null;
}

/**
* java对象转换为json字符串
*
* @param object
*            要转换的对象
* @param filterName
*            过滤器的名称
* @param properties
*            要过滤哪些字段
* @return
*/
@SuppressWarnings("deprecation")
public static String fromObjectToJson(Object object, String filterName, Set<String> properties) {
ObjectMapper mapper = new ObjectMapper();
FilterProvider filters = new SimpleFilterProvider().addFilter(filterName, SimpleBeanPropertyFilter.serializeAllExcept(properties));
try {
return mapper.filteredWriter(filters).writeValueAsString(object);
} catch (JsonGenerationException e) {
logger.error("JsonGenerationException: ", e);
} catch (JsonMappingException e) {
logger.error("JsonMappingException: ", e);
} catch (IOException e) {
logger.error("IOException: ", e);
}
return null;
}

/**
* java对象转换为json字符串
*
* @param object
*            要转换的对象
* @param filterName
*            过滤器的名称
* @param properties
*            要过滤的字段名称
* @return
*/
@SuppressWarnings("deprecation")
public static String fromObjectToJson(Object object, String filterName, String property) {
ObjectMapper mapper = new ObjectMapper();
FilterProvider filters = new SimpleFilterProvider().addFilter(filterName, SimpleBeanPropertyFilter.serializeAllExcept(property));
try {
return mapper.filteredWriter(filters).writeValueAsString(object);
} catch (JsonGenerationException e) {
logger.error("JsonGenerationException: ", e);
} catch (JsonMappingException e) {
logger.error("JsonMappingException: ", e);
} catch (IOException e) {
logger.error("IOException: ", e);
}
return null;
}

/**
* java对象(包含日期字段或属性)转换为json字符串
*
* @param object
*            Java对象
* @return 返回字符串
*/
public static String fromObjectHasDateToJson(Object object) {
ObjectMapper mapper = new ObjectMapper();
mapper.getSerializationConfig().withDateFormat(new SimpleDateFormat(DATE_TIME_FORMAT));
try {
return mapper.writeValueAsString(object);
} catch (JsonGenerationException e) {
logger.error("JsonGenerationException: ", e);
} catch (JsonMappingException e) {
logger.error("JsonMappingException: ", e);
} catch (IOException e) {
logger.error("IOException: ", e);
}
return null;
}

/**
* java对象(包含日期字段或属性)转换为json字符串
*
* @param object
*            Java对象
* @param dateTimeFormatString
*            自定义的日期/时间格式。该属性的值遵循java标准的date/time格式规范。如：yyyy-MM-dd
* @return 返回字符串
*/
public static String fromObjectHasDateToJson(Object object, String dateTimeFormatString) {
ObjectMapper mapper = new ObjectMapper();
mapper.getSerializationConfig().withDateFormat(new SimpleDateFormat(dateTimeFormatString));
try {
return mapper.writeValueAsString(object);
} catch (JsonGenerationException e) {
logger.error("JsonGenerationException: ", e);
} catch (JsonMappingException e) {
logger.error("JsonMappingException: ", e);
} catch (IOException e) {
logger.error("IOException: ", e);
}
return null;
}
public static JavaType getCollectionType(Class<?> collectionClass, Class<?>... elementClasses) {
ObjectMapper mapper = new ObjectMapper();
return mapper.getTypeFactory().constructParametricType(collectionClass, elementClasses);
}
}