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Java map和bean互转常用的方法总结

作者：我老菜

这篇文章主要给大家介绍了关于Java中map和bean互转常用方法的相关资料,平时日常Java开发,经常会涉及到Java Bean和Map之间的类型转换,需要的朋友可以参考下

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<String, Object> 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> T beanUtils_mapToObject(Map<String, Object> map, Class<T> 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 2023
Exception in thread "main" java.lang.ClassCastException: java.util.HashMap cannot be cast to com.example.demo.map2bean.LTDemo
    at 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> T BeanMapMapToObject(Map<String, Object> map, Class<T> 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<String, Object> BeanMapObjectToMap(Object obj) {
        Map<String, Object> 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.LTDemo
    at 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<String, Object> 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<String, Object> reflectObjectToMap(Object obj) throws Exception {
        if (obj == null) {
            return null;
        }
        Map<String, Object> map = new HashMap<String, Object>();
        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.LTDemo
    at 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> T introspector_mapToObject(Map<String, Object> map, Class<T> 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<String, Object> introspector_objectToMap(Object obj) throws Exception {
        if (obj == null) {
            return null;
        }
        Map<String, Object> map = new HashMap<String, Object>();
        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.LTDemo
    at com.example.demo.map2bean.MapToBean.main(MapToBean.java:65)

总结

到此这篇关于Java map和bean互转常用方法的文章就介绍到这了,更多相关Java map和bean互转内容请搜索脚本之家以前的文章或继续浏览下面的相关文章希望大家以后多多支持脚本之家！

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