(1)把list 转化为map
场景:系统中有一个字典类,是一个实体类,如下(省略了getter,setter方法):
/**
* data dictionary entity
*/
@entity
@table(name = "t_dictionary")
public class commondictionary implements cloneable, serializable {
private static final long serialversionuid = 0x33d260729eadd26el;
/**
* 主键id
*/
private long id;
* 组id
private string groupid;
* 键<br />不能取值为key,因为key是关键字
private string key2;
* 值
private string value;
* 描述
private string description;
public commondictionary clone() throws clonenotsupportedexception {
return (commondictionary) super.clone();
}
方法如下 :
/***
*
* @param list
* @param clazz
* @param keyproperty : 该成员变量的值作为map的key
* @param valueproperty : 该成员变量的值作为map的value
* @return
public static map<string,object> parseobjectlist(list list,class clazz,string keyproperty,string valueproperty){
map<string,object> map=new hashmap<string, object>();
for(int i=0;i<list.size();i++){
object obj=list.get(i);
field keyf =null;
field valuef =null;
try {
keyf = clazz.getdeclaredfield(keyproperty);
} catch (nosuchfieldexception e) {
keyf= getspecifiedfield(clazz.getsuperclass()/*
* may be null if it is
* object .
*/, keyproperty);
// e.printstacktrace();
}
valuef = clazz.getdeclaredfield(valueproperty);
valuef= getspecifiedfield(clazz.getsuperclass()/*
*/, valueproperty);
keyf.setaccessible(true);
valuef.setaccessible(true);
map.put((string)keyf.get(obj), valuef.get(obj));
} catch (illegalargumentexception e) {
e.printstacktrace();
} catch (illegalaccessexception e) {
}
return map;
依赖的方法:
* get specified field
* @param fieldname
public static field getspecifiedfield(class<?> clazz, string fieldname) {
field f = null;
if (valuewidget.isnullorempty(clazz)) {
return null;
try {
f = clazz.getdeclaredfield(fieldname);
} catch (nosuchfieldexception e) {
return getspecifiedfield(clazz.getsuperclass()/*
* may be null if it is
* object .
*/, fieldname);
// e.printstacktrace();
return f;
使用实例:
list<commondictionary> anticounterfeit=dictionaryparam.getlist(constant2.dictionary_group_anticounterfeit_code);
qrsettingsbean qrsettingsbean=new qrsettingsbean();
map<string,object>map=reflecthwutils.parseobjectlist(anticounterfeit, commondictionary.class, "key2", "value");
reflecthwutils.setobjectvalue(qrsettingsbean, map);
model.addattribute("qrsettingsbean", qrsettingsbean);
(2)把map 转化为java对象,map的key对应对象的成员变量的名称
* 利用反射设置对象的属性值. 注意:属性可以没有setter 方法.
* @param obj
* @param params
* @throws securityexception
* @throws nosuchfieldexception
* @throws illegalargumentexception
* @throws illegalaccessexception
public static void setobjectvalue(object obj, map<string, object> params)
throws securityexception, nosuchfieldexception,
illegalargumentexception, illegalaccessexception {
if (valuewidget.isnullorempty(params)) {
return;
class<?> clazz = obj.getclass();
for (iterator it = params.entryset().iterator(); it.hasnext();) {
map.entry<string, object> entry = (map.entry<string, object>) it
.next();
string key = entry.getkey();
object propertyvalue = entry.getvalue();
if (valuewidget.isnullorempty(propertyvalue)) {
continue;
field name = getspecifiedfield(clazz, key);
if (name != null) {
name.setaccessible(true);
name.set(obj, propertyvalue);
(3)把对象中 值为空字符串的成员变量 ,将其值改为null
* 把对象中空字符串改为null
* @param obj : 要修改的对象:java bean
public static void convertempty2null(object obj)
throws securityexception, nosuchfieldexception, illegalargumentexception, illegalaccessexception{
list<field> fieldslist =getallfieldlist(obj.getclass());
for(int i=0;i<fieldslist.size();i++){
field f=fieldslist.get(i);
object vobj=getobjectvalue(obj,f );
if(f.gettype().getname().equals("java.lang.string") && (vobj instanceof string) ){
string str=(string)vobj;
if(systemhwutil.empty.equals(str)){
// system.out.println(f.getname());
// system.out.println(f.gettype().getname());
f.setaccessible(true);
f.set(obj, null);
}
* get all field ,including fields in father/super class
public static list<field> getallfieldlist(class<?> clazz) {
list<field> fieldslist = new arraylist<field>();// return object
if (clazz == null) {
class<?> superclass = clazz.getsuperclass();// father class
if (!superclass.getname().equals(object.class.getname()))/*
* java.lang.object
*/{
// system.out.println("has father");
fieldslist.addall(getallfieldlist(superclass));// recursive
field[] fields = clazz.getdeclaredfields();
for (int i = 0; i < fields.length; i++) {
field field = fields[i];
// 排除因实现serializable 接口而产生的属性serialversionuid
if (!field.getname().equals("serialversionuid")) {
fieldslist.add(field);
return fieldslist;
* 获取指定对象的属性值
* @param name
* :field
public static object getobjectvalue(object obj, field name)
// field f = getspecifiedfield(obj.getclass(), name.getname());
if (name == null) {
system.out.println("[reflecthwutils.getobjectvalue]"
+ obj.getclass().getname() + " does not has field " + name);
name.setaccessible(true);
return name.get(obj);
(4)判断两个对象的属性值是否都相等.
* 判断两个对象的属性值是否都相等.
* @param obj1
* @param obj2
* @param exclusiveproperties
* : 要过滤的属性
public static boolean issamepropertyvalue(object obj1, object obj2,
list<string> exclusiveproperties) throws securityexception,
illegalargumentexception, nosuchfieldexception,
illegalaccessexception {
list<field> fieldslist = getallfieldlist(obj1.getclass());
for (int i = 0; i < fieldslist.size(); i++) {
field f = fieldslist.get(i);
if ((!valuewidget.isnullorempty(exclusiveproperties))
&& exclusiveproperties.contains(f.getname())) {// 过滤掉，不比较
object propertyvalue1 = getobjectvalue(obj1, f);
object propertyvalue2 = getobjectvalue(obj2, f);
system.out.println(f.getname());
if (propertyvalue1 == propertyvalue2) {// if propertyvalue1 is null
if (!issamebysimpletypes(propertyvalue1, propertyvalue2)) {
return false;
return true;
* 比较java 基本类型的值是否相同.
* : string,integer,double,boolean
public static boolean issamebysimpletypes(object obj1, object obj2) {
if (obj1 == obj2) {
return true;
if (obj1 instanceof integer) {// int
integer int1 = (integer) obj1;
integer int2 = (integer) obj2;
return int1.intvalue() == int2.intvalue();
} else if (obj1 instanceof double) {// double
double double1 = (double) obj1;
double double2 = (double) obj2;
return double1.compareto(double2) == 0;
} else if (obj1 instanceof boolean) {// double
boolean boolean1 = (boolean) obj1;
boolean boolean2 = (boolean) obj2;
return boolean1.compareto(boolean2) == 0;
} else if (obj1 instanceof string) {
string str1 = (string) obj1;
string str2 = (string) obj2;
return str1.equals(str2);
} else if (obj1 instanceof timestamp) {
timestamp time1 = (timestamp) obj1;
timestamp time2 = (timestamp) obj2;
return time1.compareto(time2) == 0;
} else if (obj1 instanceof java.util.date) {
java.util.date time1 = (java.util.date) obj1;
java.util.date time2 = (java.util.date) obj2;
} else if (obj1 instanceof java.sql.date) {
java.sql.date time1 = (java.sql.date) obj1;
java.sql.date time2 = (java.sql.date) obj2;
return obj1 == obj2;
}
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