JavaWeb - Util 之 JsonUtil

packagecom.mmall.util;
importcom.google.common.collect.Lists;
importcom.mmall.pojo.Category;
importcom.mmall.pojo.TestPojo;
importcom.mmall.pojo.User;
importlombok.extern.slf4j.Slf4j;
importorg.apache.commons.lang.StringUtils;
importorg.codehaus.jackson.map.DeserializationConfig;
importorg.codehaus.jackson.map.ObjectMapper;
importorg.codehaus.jackson.map.SerializationConfig;
importorg.codehaus.jackson.map.annotate.JsonSerialize.Inclusion;
importorg.codehaus.jackson.type.JavaType;
importorg.codehaus.jackson.type.TypeReference;
importjava.io.IOException;
importjava.text.SimpleDateFormat;
importjava.util.Date;
importjava.util.HashMap;
importjava.util.List;
importjava.util.Map;
@Slf4jpublicclassJsonUtil {
privatestaticObjectMapperobjectMapper=newObjectMapper();
static{
// 对象的所有字段全部列入objectMapper.setSerializationInclusion(Inclusion.ALWAYS);
// 取消默认转换timestamps形式objectMapper.configure(SerializationConfig.Feature.WRITE_DATES_AS_TIMESTAMPS,false);
// 忽略空bean转json的错误objectMapper.configure(SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS,false);
// 所有的日期格式都统一为以下的样式，即yyyy-MM-dd HH:mm:ssobjectMapper.setDateFormat(newSimpleDateFormat(DateTimeUtil.STANDARD_FORMAT));
// 忽略在json字符串中存在，但是在java对象中不存在对应属性的情况，防止错误objectMapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES,false);
    }
publicstatic<T>Stringobj2String(Tobj){
if(obj==null){
returnnull;
        }
try {
returnobjinstanceofString? (String)obj :  objectMapper.writeValueAsString(obj);
        } catch (Exceptione) {
log.warn("Parse Object to String error",e);
returnnull;
        }
    }
publicstatic<T>Stringobj2StringPretty(Tobj){
if(obj==null){
returnnull;
        }
try {
returnobjinstanceofString? (String)obj :  objectMapper.writerWithDefaultPrettyPrinter().writeValueAsString(obj);
        } catch (Exceptione) {
log.warn("Parse Object to String error",e);
returnnull;
        }
    }
publicstatic<T>Tstring2Obj(Stringstr,Class<T>clazz){
if(StringUtils.isEmpty(str) ||clazz==null){
returnnull;
        }
try {
returnclazz.equals(String.class)? (T)str : objectMapper.readValue(str,clazz);
        } catch (Exceptione) {
log.warn("Parse String to Object error",e);
returnnull;
        }
    }
publicstatic<T>Tstring2Obj(Stringstr, TypeReference<T>typeReference){
if(StringUtils.isEmpty(str) ||typeReference==null){
returnnull;
        }
try {
return (T)(typeReference.getType().equals(String.class)?str : objectMapper.readValue(str,typeReference));
        } catch (Exceptione) {
log.warn("Parse String to Object error",e);
returnnull;
        }
    }
publicstatic<T>Tstring2Obj(Stringstr,Class<?>collectionClass,Class<?>... elementClasses){
JavaTypejavaType=objectMapper.getTypeFactory().constructParametricType(collectionClass,elementClasses);
try {
returnobjectMapper.readValue(str,javaType);
        } catch (Exceptione) {
log.warn("Parse String to Object error",e);
returnnull;
        }
    }
publicstaticvoidmain(String[] args) {
TestPojotestPojo=newTestPojo();
testPojo.setName("Geely");
testPojo.setId(666);
//{"name":"Geely","id":666}Stringjson="{\"name\":\"Geely\",\"color\":\"blue\",\"id\":666}";
TestPojotestPojoObject=JsonUtil.string2Obj(json,TestPojo.class);
//        String testPojoJson = JsonUtil.obj2String(testPojo);//        log.info("testPojoJson:{}",testPojoJson);log.info("end");
//        User user = new User();//        user.setId(2);//        user.setEmail("geely@happymmall.com");//        user.setCreateTime(new Date());//        String userJsonPretty = JsonUtil.obj2StringPretty(user);//        log.info("userJson:{}",userJsonPretty);//        User u2 = new User();//        u2.setId(2);//        u2.setEmail("geelyu2@happymmall.com");////////        String user1Json = JsonUtil.obj2String(u1);////        String user1JsonPretty = JsonUtil.obj2StringPretty(u1);////        log.info("user1Json:{}",user1Json);////        log.info("user1JsonPretty:{}",user1JsonPretty);//////        User user = JsonUtil.string2Obj(user1Json,User.class);//////        List<User> userList = Lists.newArrayList();//        userList.add(u1);//        userList.add(u2);////        String userListStr = JsonUtil.obj2StringPretty(userList);////        log.info("==================");////        log.info(userListStr);//////        List<User> userListObj1 = JsonUtil.string2Obj(userListStr, new TypeReference<List<User>>() {//        });//////        List<User> userListObj2 = JsonUtil.string2Obj(userListStr,List.class,User.class);System.out.println("end");
    }
}