常用的map转bean互转方法
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常用的map转bean互转方法
一、hutool工具类
这个很常用，还支持将蛇形转成驼，如：apply_time 会赋值到applyTime上
LTDemo ltDemo = BeanUtil.mapToBean(map, LTDemo.class, true, CopyOptions.create()); Map demoMap = BeanUtil.beanToMap(ltDemo); System.out.println("输出map -> bean: " + ltDemo.toString()); System.out.println("输出bean -> map : " + demoMap); System.out.println(ltDemo.getApplyTime()); System.out.println(ltDemo.getChildren()); ltDemo.getChildren().forEach(children -> System.out.println(children.toString())); ltDemo.getChildren().forEach(children -> System.out.println(children.getAddress())); 输出原生map: {address=上海市, children=[{address=上海市, name=小张, apply_time=Fri Mar 03 17:21:01 CST 2023, age=2}], name=张三, apply_time=Fri Mar 03 17:21:01 CST 2023, age=20}输出map -> bean: LTDemo(name=张三, age=20, address=上海市, applyTime=Fri Mar 03 17:21:01 CST 2023, children=[LTDemo(name=小张, age=2, address=上海市, applyTime=Fri Mar 03 17:21:01 CST 2023, children=[])])输出bean -> map : {name=张三, age=20, address=上海市, applyTime=Fri Mar 03 17:21:01 CST 2023, children=[LTDemo(name=小张, age=2, address=上海市, applyTime=Fri Mar 03 17:21:01 CST 2023, children=[])]}Fri Mar 03 17:21:01 CST 2023[LTDemo(name=小张, age=2, address=上海市, applyTime=Fri Mar 03 17:21:01 CST 2023, children=[])]LTDemo(name=小张, age=2, address=上海市, applyTime=Fri Mar 03 17:21:01 CST 2023, children=[])上海市二、fastjson工具类
这个也很常用，也支持将蛇型转成驼峰，
如：apply_time 会赋值到applyTime上
LTDemo ltDemo = JSONObject.parseObject(JSONObject.toJSONString(map), LTDemo.class); Map demoMap = JSONObject.parseObject(JSONObject.toJSONString(ltDemo), Map.class); System.out.println("输出map -> bean: " + ltDemo.toString()); System.out.println("输出bean -> map : " + demoMap); System.out.println(ltDemo.getApplyTime()); System.out.println(ltDemo.getChildren()); ltDemo.getChildren().forEach(children -> System.out.println(children.toString())); ltDemo.getChildren().forEach(children -> System.out.println(children.getAddress()));输出原生map: {address=上海市, children=[{address=上海市, name=小张, apply_time=Fri Mar 03 17:21:59 CST 2023, age=2}], name=张三, apply_time=Fri Mar 03 17:21:59 CST 2023, age=20}输出map -> bean: LTDemo(name=张三, age=20, address=上海市, applyTime=Fri Mar 03 17:21:59 CST 2023, children=[LTDemo(name=小张, age=2, address=上海市, applyTime=Fri Mar 03 17:21:59 CST 2023, children=[])])输出bean -> map : {address=上海市, children=[{"address":"上海市","children":[],"name":"小张","applyTime":1677835319813,"age":2}], name=张三, applyTime=1677835319813, age=20}Fri Mar 03 17:21:59 CST 2023[LTDemo(name=小张, age=2, address=上海市, applyTime=Fri Mar 03 17:21:59 CST 2023, children=[])]LTDemo(name=小张, age=2, address=上海市, applyTime=Fri Mar 03 17:21:59 CST 2023, children=[])上海市三、beanutils_BeanUtils工具类 不太好用
嵌套型map，转换会有问题，且不支持蛇型转成驼峰
//------------------- beanutils_BeanUtils ----------------- //map转java对象 public static T beanUtils_mapToObject(Map map, Class clazz) throws Exception { if (map == null) { return null; } T bean = clazz.newInstance(); BeanUtils.populate(bean, map); return bean; } LTDemo ltDemo = beanUtils_mapToObject(map, LTDemo.class); System.out.println("输出map -> bean: " + ltDemo.toString()); System.out.println(ltDemo.getApplyTime()); System.out.println(ltDemo.getChildren().get(0).getApplyTime());输出map -> bean: LTDemo(name=张三, age=20, address=上海市, applyTime=Fri Mar 03 17:04:38 CST 2023, children=[{address=上海市, name=小张, applyTime=Fri Mar 03 17:04:38 CST 2023, age=2}])Fri Mar 03 17:04:38 CST 2023Exception in thread "main" java.lang.ClassCastException: java.util.HashMap cannot be cast to com.example.demo.map2bean.LTDemoat com.example.demo.map2bean.MapToBean.main(MapToBean.java:73)四、cglib BeanMap工具类 不太好用
这个也很常用，也支持将蛇形转成驼，如：apply_time 会赋值到applyTime上
import net.sf.cglib.beans.BeanMap; // ------------------- cglib BeanMap ------------------- //map对象转java public static T BeanMapMapToObject(Map map, Class beanClass) throws Exception { T object = beanClass.newInstance(); BeanMap beanMap = BeanMap.create(object); beanMap.putAll(map); return object; } //java对象转map public static Map BeanMapObjectToMap(Object obj) { Map map = Maps.newHashMap(); if (obj != null) { BeanMap beanMap = BeanMap.create(obj); for (Object key : beanMap.keySet()) { map.put(key + "", beanMap.get(key)); } } return map; } LTDemo ltDemo = beanMapMapToObject(map, LTDemo.class); Map demoMap = beanMapObjectToMap(ltDemo); System.out.println("输出map -> bean: " + ltDemo.toString()); System.out.println("输出bean -> map : " + demoMap); System.out.println(ltDemo.getApplyTime()); System.out.println(ltDemo.getChildren()); ltDemo.getChildren().forEach(children -> System.out.println(children.toString()));输出原生map: {address=上海市, children=[{address=上海市, name=小张, apply_time=Fri Mar 03 17:12:45 CST 2023, age=2}], name=张三, apply_time=Fri Mar 03 17:12:45 CST 2023, age=20}输出map -> bean: LTDemo(name=张三, age=20, address=上海市, applyTime=null, children=[{address=上海市, name=小张, apply_time=Fri Mar 03 17:12:45 CST 2023, age=2}])输出bean -> map : {address=上海市, children=[{address=上海市, name=小张, apply_time=Fri Mar 03 17:12:45 CST 2023, age=2}], name=张三, applyTime=null, age=20}null[{address=上海市, name=小张, apply_time=Fri Mar 03 17:12:45 CST 2023, age=2}]Exception in thread "main" java.lang.ClassCastException: java.util.HashMap cannot be cast to com.example.demo.map2bean.LTDemoat java.util.ArrayList.forEach(ArrayList.java:1259)at com.example.demo.map2bean.MapToBean.main(MapToBean.java:75)五、reflect 反射来玩 不太好玩
//------------------- reflect ------------------- //map转java对象 public static Object reflectMapToObject(Map map, Class beanClass) throws Exception { if (map == null) { return null; } Object object = beanClass.newInstance(); Field[] fields = beanClass.getDeclaredFields(); for (Field field : fields) { int mod = field.getModifiers(); if (Modifier.isFinal(mod) || Modifier.isStatic(mod)) { continue; } field.setAccessible(true); field.set(object, map.get(field.getName())); } return object; } //java对象转map public static Map reflectObjectToMap(Object obj) throws Exception { if (obj == null) { return null; } Map map = new HashMap(); Field[] declaredFields = obj.getClass().getDeclaredFields(); for (Field field : declaredFields) { field.setAccessible(true); map.put(field.getName(), field.get(obj)); } return map; } LTDemo ltDemo = reflectMapToObject(map,LTDemo.class); Map demoMap = reflectObjectToMap(ltDemo); System.out.println("输出map -> bean: " + ltDemo.toString()); System.out.println("输出bean -> map : " + demoMap); System.out.println(ltDemo.getApplyTime()); System.out.println(ltDemo.getChildren()); ltDemo.getChildren().forEach(children -> System.out.println(children.toString()));输出原生map: {address=上海市, children=[{address=上海市, name=小张, apply_time=Fri Mar 03 17:16:35 CST 2023, age=2}], name=张三, apply_time=Fri Mar 03 17:16:35 CST 2023, age=20}输出map -> bean: LTDemo(name=张三, age=20, address=上海市, applyTime=null, children=[{address=上海市, name=小张, apply_time=Fri Mar 03 17:16:35 CST 2023, age=2}])输出bean -> map : {address=上海市, children=[{address=上海市, name=小张, apply_time=Fri Mar 03 17:16:35 CST 2023, age=2}], name=张三, applyTime=null, age=20}null[{address=上海市, name=小张, apply_time=Fri Mar 03 17:16:35 CST 2023, age=2}]Exception in thread "main" java.lang.ClassCastException: java.util.HashMap cannot be cast to com.example.demo.map2bean.LTDemoat java.util.ArrayList.forEach(ArrayList.java:1259)at com.example.demo.map2bean.MapToBean.main(MapToBean.java:84)六、Introspector类 不太好用
这个用起来，只能转换第一层，而且不支持蛇型转驼峰
import java.beans.BeanInfo;import java.beans.Introspector;import java.beans.PropertyDescriptor; //----------------- Introspector ------------------ //map转java对象 public static T introspector_mapToObject(Map map, Class clazz) throws Exception { if (map == null) { return null; } T bean = clazz.newInstance(); BeanInfo beanInfo = Introspector.getBeanInfo(bean.getClass()); PropertyDescriptor[] propertyDescriptors = beanInfo.getPropertyDescriptors(); for (PropertyDescriptor property : propertyDescriptors) { Method setter = property.getWriteMethod(); if (setter != null) { setter.invoke(bean, map.get(property.getName())); } } return bean; } //java对象转map public static Map introspector_objectToMap(Object obj) throws Exception { if (obj == null) { return null; } Map map = new HashMap(); BeanInfo beanInfo = Introspector.getBeanInfo(obj.getClass()); PropertyDescriptor[] propertyDescriptors = beanInfo .getPropertyDescriptors(); for (PropertyDescriptor property : propertyDescriptors) { String key = property.getName(); if (key.compareToIgnoreCase("class") == 0) { continue; } Method getter = property.getReadMethod(); Object value = getter != null ? getter.invoke(obj) : null; map.put(key, value); } return map; } LTDemo ltDemo = introspector_mapToObject(map, LTDemo.class); Map demoMap = introspector_objectToMap(ltDemo); System.out.println("输出map -> bean: " + ltDemo.toString()); System.out.println("输出bean -> map : " + demoMap); System.out.println(ltDemo.getApplyTime()); System.out.println(ltDemo.getChildren()); System.out.println(ltDemo.getChildren().get(0).toString());输出原生map: {address=上海市, children=[{address=上海市, name=小张, apply_time=Fri Mar 03 16:56:37 CST 2023, age=2}], name=张三, apply_time=Fri Mar 03 16:56:37 CST 2023, age=20}输出map -> bean: LTDemo(name=张三, age=20, address=上海市, applyTime=null, children=[{address=上海市, name=小张, apply_time=Fri Mar 03 16:56:37 CST 2023, age=2}])输出bean -> map : {address=上海市, children=[{address=上海市, name=小张, apply_time=Fri Mar 03 16:56:37 CST 2023, age=2}], name=张三, applyTime=null, age=20}null[{address=上海市, name=小张, apply_time=Fri Mar 03 16:56:37 CST 2023, age=2}]Exception in thread "main" java.lang.ClassCastException: java.util.HashMap cannot be cast to com.example.demo.map2bean.LTDemoat com.example.demo.map2bean.MapToBean.main(MapToBean.java:65)总结
不想说啥…看着用吧
来源地址：https://blog.csdn.net/qq_37700773/article/details/129323025
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