Object轉Map
包:import java.lang.reflect.Field;
public static Map<String,Object> Obj2Map(Object obj) throws Exception{
Map<String,Object> map=new HashMap<String, Object>();
Field[] fields = obj.getClass().getDeclaredFields();
for(Field field:fields){
field.setAccessible(true);
map.put(field.getName(), field.get(obj));
}
return map;
}
Map轉String
public static String MapToJsonStr(Map<String,Object> map) throws IOException{
ObjectMapper objectMapper = new ObjectMapper();
String result = objectMapper.writeValueAsString(map);
return result;
}
String轉List
public static List<Object> JsonStrToList(String str) throws IOException{
List<Object> result = new ArrayList<>();
if(str != null && !"".equals(str)) {
ObjectMapper mapper = new ObjectMapper();
result = (List) mapper.readValue(str, List.class);
}
return result;
}
String數組轉List,List轉String數組
List 轉換爲 String數組
List<String> list = new ArrayList<String>();
list.add("a1");
list.add("a2");
String[] toBeStored = list.toArray(new String[list.size()]);
for(String s : toBeStored) {
System.out.println(s);
}
String 數組轉換爲 List
String[] arr = new String[] {"1", "2"};
List list = Arrays.asList(arr);
String轉Map
public static HashMap<String,Object> JsonStrToMap(String str) throws IOException{
HashMap<String,Object> result = new HashMap<>();
if(str != null && !"".equals(str)) {
ObjectMapper mapper = new ObjectMapper();
result = (HashMap) mapper.readValue(str, Map.class);
}
return result;
}
Object [] 數組轉map
格式:Object mapStr = "[Mexico=32432432432, Sort=哈哈, md=無/無,序號=1, Type=新聞, name=佚名]";
String str = mapStr.toString();
String cms =str.replace("[", "").replace("]", "");
String [] countryMapStr = cms.split(",");
Map<String,String> countryMap = new HashMap<String,String>();
for(String s:countryMapStr ){
String[] ms = s.split("=");
countryMap.put(ms[0].trim(), ms[1].trim());
}
List集合去重
public static List removeDuplicate(List list) {
HashSet h = new HashSet(list);
list.clear();
list.addAll(h);
return list;
}
JSON字符串轉換爲Map
導入阿里巴巴封裝的FastJSON的jar包
package com.zkn.newlearn.json;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;
import java.util.Map;
/**
* JSON字符串自動轉換
* Created by zkn on 2016/8/22.
*/
public class JsonToMapTest01 {
public static void main(String[] args){
String str = "{\"0\":\"zhangsan\",\"1\":\"lisi\",\"2\":\"wangwu\",\"3\":\"maliu\"}";
//第一種方式
Map maps = (Map)JSON.parse(str);
System.out.println("這個是用JSON類來解析JSON字符串!!!");
for (Object map : maps.entrySet()){
System.out.println(((Map.Entry)map).getKey()+" " + ((Map.Entry)map).getValue());
}
//第二種方式
Map mapTypes = JSON.parseObject(str);
System.out.println("這個是用JSON類的parseObject來解析JSON字符串!!!");
for (Object obj : mapTypes.keySet()){
System.out.println("key爲:"+obj+"值爲:"+mapTypes.get(obj));
}
//第三種方式
Map mapType = JSON.parseObject(str,Map.class);
System.out.println("這個是用JSON類,指定解析類型,來解析JSON字符串!!!");
for (Object obj : mapType.keySet()){
System.out.println("key爲:"+obj+"值爲:"+mapType.get(obj));
}
//第四種方式
/**
* JSONObject是Map接口的一個實現類
*/
Map json = (Map) JSONObject.parse(str);
System.out.println("這個是用JSONObject類的parse方法來解析JSON字符串!!!");
for (Object map : json.entrySet()){
System.out.println(((Map.Entry)map).getKey()+" "+((Map.Entry)map).getValue());
}
//第五種方式
/**
* JSONObject是Map接口的一個實現類
*/
JSONObject jsonObject = JSONObject.parseObject(str);
System.out.println("這個是用JSONObject的parseObject方法來解析JSON字符串!!!");
for (Object map : json.entrySet()){
System.out.println(((Map.Entry)map).getKey()+" "+((Map.Entry)map).getValue());
}
//第六種方式
/**
* JSONObject是Map接口的一個實現類
*/
Map mapObj = JSONObject.parseObject(str,Map.class);
System.out.println("這個是用JSONObject的parseObject方法並執行返回類型來解析JSON字符串!!!");
for (Object map: json.entrySet()){
System.out.println(((Map.Entry)map).getKey()+" "+((Map.Entry)map).getValue());
}
String strArr = "{{\"0\":\"zhangsan\",\"1\":\"lisi\",\"2\":\"wangwu\",\"3\":\"maliu\"}," +
"{\"00\":\"zhangsan\",\"11\":\"lisi\",\"22\":\"wangwu\",\"33\":\"maliu\"}}";
// JSONArray.parse()
System.out.println(json);
}
}
Object轉String[]數組
Object l = it.remove(-1, 1, 3);
String[] newarray = null;
if (l.getClass().isArray()) {
int length = Array.getLength(l);
newarray = new String[length];
for (int i = 0; i < length; i++) {
newarray[i] = String.valueOf(Array.get(l, i));
}
}
for (String str : newarray) {
System.out.println(str);
}
Object轉String類型
(1)Object.toString():
(2)(String)object
(3)String.valueOf(Object)
String 轉 Date
導入 java.util.Date date=null;
date=java.sql.Date.valueOf(String s);