js将对象会集合转换为json字符串。Jackson

首先弄个工具类：

public class JacksonUtil {

public static ObjectMapper objectMapper;

/**

* 使用泛型方法，把json字符串转换为相应的JavaBean对象。

* (1)转换为普通JavaBean：readValue(json,Student.class)

* (2)转换为List,如List<Student>,将第二个参数传递为Student

* [].class.然后使用Arrays.asList();方法把得到的数组转换为特定类型的List

*

* @param jsonStr

* @param valueType

* @return

*/

public static <T> T readValue(String jsonStr, Class<T> valueType) {

if (objectMapper == null) {

objectMapper = new ObjectMapper();

}

try {

return objectMapper.readValue(jsonStr, valueType);

} catch (Exception e) {

e.printStackTrace();

}

return null;

}

/**

* json数组转List

* @param jsonStr

* @param valueTypeRef

* @return

*/

public static <T> T readValue(String jsonStr, TypeReference<T> valueTypeRef){

if (objectMapper == null) {

objectMapper = new ObjectMapper();

}

try {

return objectMapper.readValue(jsonStr, valueTypeRef);

} catch (Exception e) {

e.printStackTrace();

}

return null;

}

/**

* 把JavaBean转换为json字符串

*

* @param object

* @return

*/

public static String toJSon(Object object) {

if (objectMapper == null) {

objectMapper = new ObjectMapper();

}

try {

return objectMapper.writeValueAsString(object);

} catch (Exception e) {

e.printStackTrace();

}

return null;

}

后台弄个对象或集合：

ObjectMapper mapper =CommonUtil.getMapperInstance(false);

Option option1=new Option();

option1.setId("1-1");

option1.setTitle("动感地带");

Option option2=new Option();

option2.setId("1-2");

option2.setTitle("神州行");

Option option3=new Option();

option3.setId("1-3");

option3.setTitle("全球通");

List<Option> optionList1=new ArrayList<Option>();

optionList1.add(option1);

optionList1.add(option2);

optionList1.add(option3);

Topic topic1=new Topic();

topic1.setId("1");

topic1.setTitle("【第一题：请问您使用目前中国移动的哪种品牌？】");

topic1.setOptionList(optionList1);

Option option4=new Option();

option4.setId("2-1");

option4.setTitle("很差");

Option option5=new Option();

option5.setId("2-2");

option5.setTitle("差");

Option option6=new Option();

option6.setId("2-3");

option6.setTitle("好");

List<Option> optionList2=new ArrayList<Option>();

optionList2.add(option4);

optionList2.add(option5);

optionList2.add(option6);

Topic topic2=new Topic();

topic2.setId("2");

topic2.setTitle("【第二题：您觉得中国移动服务营业厅的整体环境怎么样？】");

topic2.setOptionList(optionList2);

List<Topic> topicList=new ArrayList<Topic>();

topicList.add(topic1);

topicList.add(topic2);

Template template=new Template();

template.setId("1");

template.setTitle("10086满意度调查");

template.setTopicList(topicList);

System.out.println("将模板实体转换为JSON="+JacksonUtil.toJSon(template));

System.out.println("将集合转换为JSON="+JacksonUtil.toJSon(topicList));

CommonUtil

private static ObjectMapper mapper;

/**

*

*

* @param createNew

* 是否创建一个新的Mapper

* @return

*/

public static synchronized ObjectMapper getMapperInstance(boolean createNew) {

if (createNew) {

return new ObjectMapper();

} else if (mapper == null) {

mapper = new ObjectMapper();

}

return mapper;

}