关于泛型的几个代码片断
关于泛型的几个代码片段
1、方法参数为泛型类型
private <T> List<T> changeDatas(
List<DataInfo> dataes,Class<T> a) {
List<T> ans = new ArrayList<T>();
try {
if (!CollectionUtils.isEmpty(dataes)) {
for (DataInfo _data : dataes) {
T newD = a.newInstance();
BeanUtils.copyProperties(newD, _data);
ans.add(newD);
}
}
} catch (Exception e) {
e.printStackTrace();
}
return ans;
}
2、自己写的一个关于序列化，反序列化，json转换的工具类，使用到泛型类型的例子
public class MockUtil {
public static FitSdpShoppingDto morkShoppingDto(){
return MockUtil.deserializeObject("d:\\cache\\123123123.txt",FitSdpShoppingDto.class);
}
public static void morkCacheShoopingDto(FitSdpShoppingDto shoppingDto){
MockUtil.serializeObject(shoppingDto,"d:\\cache\\123123123.txt");
}
/**
* 读取文件
* @param fileName
* @return
*/
public static String readFile(String fileName) {
InputStream in;
try {
in = new FileInputStream(fileName);
return IOUtils.toString(in, "GBK");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
/**
* 写入文件
*
* @param fileName
* @param contant
*/
public static void writeFile(String fileName, String contant) {
PrintWriter out;
try {
out = new PrintWriter(new BufferedWriter(new FileWriter(fileName)));
out.print(contant);
out.close();
} catch (IOException e) {
System.out.println("读写文件出现异常！");
} catch (Exception e) {
System.out.println("出现异常");
}
}
public static void writeJsonToFile(String fileName, Object contant) {
PrintWriter out;
try {
out = new PrintWriter(new BufferedWriter(new FileWriter(fileName)));
out.print(toJsonStr(contant));
out.close();
} catch (IOException e) {
System.out.println("读写文件出现异常！");
} catch (Exception e) {
System.out.println("出现异常");
}
}
/**
* 从json文件中解析json串并转换成java类型
*
* @param name
* @param clazz
* @return
*/
public static <T> T createFromJsonFile(String name, TypeReference clazz) {
try {
String sqlFlie = readFile(name);
String result = sqlFlie;
if (StringUtils.isNotBlank(result)) {
ObjectMapper objectMapper = JSONMapper.getInstance();
return (T) objectMapper.readValue(result, clazz);
}
return null;
} catch (Exception ew) {
ew.printStackTrace();
return null;
}
}
/**
* 从json文件中解析json串并转换成java类型
*
* @param name
* @param clazz
* @return
*/
public static <T> T createFromJsonFile(String name, Class<T> clazz) {
try {
String sqlFlie = readFile(name);
String result = sqlFlie;
if (StringUtils.isNotBlank(result)) {
ObjectMapper objectMapper = JSONMapper.getInstance();
return (T) objectMapper.readValue(result, clazz);
}
return null;
} catch (Exception ew) {
ew.printStackTrace();
return null;
}
}
/**
* 序列化对象保存到文件中.
*
* @param shoppingDto
* @param name
*/
public static void serializeObject(Object shoppingDto, String name) {
ObjectOutputStream oo;
try {
oo = new ObjectOutputStream(new FileOutputStream(new File(name)));
oo.writeObject(shoppingDto);
System.out.println("对象序列化成功！");
oo.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
/**
* 从文件中反序列化对象.
*
* @param name
* @param clazz
* @return
*/
public static <T> T deserializeObject(String name, Class<T> clazz) {
ObjectInputStream ois;
try {
ois = new ObjectInputStream(new FileInputStream(new File(name)));
T person = (T) ois.readObject();
System.out.println("对象反序列化成功！");
return person;
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ClassNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
/**
* 解析对象为json串.
*
* @param obj
* @return
*/
public static String toJsonStr(Object obj) {
try {
return JSONMapper.getInstance().writeValueAsString(obj);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 解析json字符串为java对象.
*
* @param obj
* @param clazz
* @return
*/
public static <T> T parseJsonStr(String str, Class<T> clazz) {
try {
return (T) JSONMapper.getInstance().readValue(str, clazz);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 解析json字符串为java对象.
*
* @param str
* @param clazz
* @return
*/
public static <T> T parseJsonStr(String str, TypeReference<T> clazz) {
try {
ObjectMapper objectMapper = JSONMapper.getInstance();
objectMapper.configure(
JsonParser.Feature.ALLOW_UNQUOTED_CONTROL_CHARS, true);
return objectMapper.readValue(str, clazz);
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
public static void main(String[] aegs) throws Exception {
Long a = 1481694879609L;
System.out.println(DateUtils.parseDate(a, "yyyy-MM-dd"));;
// Date d1 = DateUtils.parseDate("2016-12-11");
// System.out.println(d1.getTime());
//
// Date d2 = DateUtils.parseDate("2016-12-13");
// System.out.println(d2.getTime());
// String inputStr = readFile("d:\\zipstr.txt");
// String callRequestStr = ZipUnZipUtils.getInstance().unzipBase642String(inputStr,"UTF-8");
// System.out.println(callRequestStr);
// System.out.println(System.currentTimeMillis());
// FlightSearchResult<FlightSearchFlightInfoDto> goFlightSearchResult2 = MockUtil
// .createFromJsonFile(
// "d:\\new_flight.txt",
// new TypeReference<FlightSearchResult<FlightSearchFlightInfoDto>>() {
// });
// String sqlFlie = readFile("d:\\老的查询往返程机票的东西.txt");
// ObjectMapper objectMapper = JSONMapper.getInstance();
// FlightSearchResult<FlightSearchFlightInfoDto> flightSearchResult =
// objectMapper
// .readValue(
// sqlFlie,
// new TypeReference<FlightSearchResult<FlightSearchFlightInfoDto>>() {
// });
// List<FlightSearchFlightInfoDto> result =
// flightSearchResult.getResults();
// for(FlightSearchFlightInfoDto d:result){
// writeFile("d:\\"+System.currentTimeMillis()+".txt",
// getJsonStr(d)+"\n\n\n" );
// }
}
}