beanutils.copyproperties复制list<map>busilist

`BeanUtils.copyProperties` 方法只能用于单个 Java 对象之间的属性复制，无法用于列表/集合中的元素属性复制。如果要复制 List<Map> 中的元素属性，可以使用循环遍历列表，对每个 Map 元素进行属性复制。示例代码如下：

for (Map<String, Object> busi : busilist) {
    MyBean myBean = new MyBean();
    BeanUtils.copyProperties(myBean, busi);
    // TODO: 对 myBean 进行操作
}

其中，`MyBean` 为目标 Java Bean 类型，`busilist` 是待复制的 List<Map> 集合。在循环中，对每个 Map 元素进行属性复制，并将复制后的 Java Bean 对象 `myBean` 用于后续的操作。

相关问题

List<SchemaRowRule> userRowRuleList = schemaRowRuleList.stream() .filter(schemaRowRuleEo -> { List<String> userList = JSONArray.parseArray(schemaRowRuleEo.getRowPermissionUserList(), String.class); List<String> orgList = JSONArray.parseArray(schemaRowRuleEo.getRowPermissionOrgList(), String.class); return userList.contains(userUid) || orgList.contains(orgCode); }) .map(schemaRowRuleEo -> { SchemaRowRule schemaRowRule = SchemaRowRule.builder().build(); BeanUtils.copyProperties(schemaRowRuleEo, schemaRowRule); return schemaRowRule; }) .collect(Collectors.toList()); List<SchemaColumnRule> userColumnRuleList = schemaColumnRuleList.stream() .filter(rule -> { if (StringUtils.isNotEmpty(rule.getColumnPermissionUserList())) { List<String> userList = JSONArray.parseArray(rule.getColumnPermissionUserList(), String.class); return userList.contains(userUid); } else if (StringUtils.isNotEmpty(rule.getColumnPermissionOrgList())) { List<String> orgList = JSONArray.parseArray(rule.getColumnPermissionOrgList(), String.class); return orgList.contains(orgCode); } return false; }) .map(rule -> { SchemaColumnRule columnRule = new SchemaColumnRule(); BeanUtils.copyProperties(rule, columnRule); return columnRule; }) .collect(Collectors.toList());代码优化

可以将一些重复的代码提前抽象出来，例如解析字符串为列表的部分可以提取为一个方法，同时可以使用方法引用的方式替换Lambda表达式，代码如下：

private <T> List<T> copyProperties(List<T> sourceList, Supplier<T> targetSupplier) {
    return sourceList.stream()
            .map(source -> {
                T target = targetSupplier.get();
                BeanUtils.copyProperties(source, target);
                return target;
            })
            .collect(Collectors.toList());
}

...

List<String> userList = parseJsonArray(schemaRowRuleEo.getRowPermissionUserList());
List<String> orgList = parseJsonArray(schemaRowRuleEo.getRowPermissionOrgList());
List<SchemaRowRule> userRowRuleList = schemaRowRuleList.stream()
        .filter(schemaRowRuleEo -> userList.contains(userUid) || orgList.contains(orgCode))
        .collect(Collectors.toList());
List<SchemaColumnRule> userColumnRuleList = schemaColumnRuleList.stream()
        .filter(rule -> {
            List<String> userList = parseJsonArray(rule.getColumnPermissionUserList());
            List<String> orgList = parseJsonArray(rule.getColumnPermissionOrgList());
            return userList.contains(userUid) || orgList.contains(orgCode);
        })
        .collect(Collectors.toList());
List<SchemaRowRule> copiedRowRuleList = copyProperties(userRowRuleList, SchemaRowRule::new);
List<SchemaColumnRule> copiedColumnRuleList = copyProperties(userColumnRuleList, SchemaColumnRule::new);

...

private List<String> parseJsonArray(String jsonArray) {
    if (StringUtils.isNotEmpty(jsonArray)) {
        return JSONArray.parseArray(jsonArray, String.class);
    }
    return Collections.emptyList();
}

List<SchemaRowRule> userRowRuleList = schemaRowRuleList.stream() .filter(schemaRowRuleEo -> { List<String> userList = JSONArray.parseArray(schemaRowRuleEo.getRowPermissionUserList(), String.class); List<String> orgList = JSONArray.parseArray(schemaRowRuleEo.getRowPermissionOrgList(), String.class); return userList.contains(userUid) || orgList.contains(orgCode); }) .map(schemaRowRuleEo -> { SchemaRowRule schemaRowRule = SchemaRowRule.builder().build(); BeanUtils.copyProperties(schemaRowRuleEo, schemaRowRule); return schemaRowRule; }) .collect(Collectors.toList()); List<SchemaColumnRule> userColumnRuleList = schemaColumnRuleList.stream() .filter(rule -> { if (StringUtils.isNotEmpty(rule.getColumnPermissionUserList())) { List<String> userList = JSONArray.parseArray(rule.getColumnPermissionUserList(), String.class); return userList.contains(userUid); } else if (StringUtils.isNotEmpty(rule.getColumnPermissionOrgList())) { List<String> orgList = JSONArray.parseArray(rule.getColumnPermissionOrgList(), String.class); return orgList.contains(orgCode); } return false; }) .map(rule -> { SchemaColumnRule columnRule = new SchemaColumnRule(); BeanUtils.copyProperties(rule, columnRule); return columnRule; }) .collect(Collectors.toList());代码优化

可以考虑使用方法引用和lambda表达式进一步简化代码：

List<SchemaRowRule> userRowRuleList = schemaRowRuleList.stream()
        .filter(schemaRowRuleEo -> {
            List<String> userList = JSON.parseArray(schemaRowRuleEo.getRowPermissionUserList(), String.class);
            List<String> orgList = JSON.parseArray(schemaRowRuleEo.getRowPermissionOrgList(), String.class);
            return userList.contains(userUid) || orgList.contains(orgCode);
        })
        .map(schemaRowRuleEo -> {
            SchemaRowRule schemaRowRule = new SchemaRowRule();
            BeanUtils.copyProperties(schemaRowRuleEo, schemaRowRule);
            return schemaRowRule;
        })
        .collect(Collectors.toList());

List<SchemaColumnRule> userColumnRuleList = schemaColumnRuleList.stream()
        .filter(rule -> {
            List<String> userList = Optional.ofNullable(rule.getColumnPermissionUserList())
                    .map(userListStr -> JSON.parseArray(userListStr, String.class))
                    .orElse(Collections.emptyList());
            List<String> orgList = Optional.ofNullable(rule.getColumnPermissionOrgList())
                    .map(orgListStr -> JSON.parseArray(orgListStr, String.class))
                    .orElse(Collections.emptyList());
            return userList.contains(userUid) || orgList.contains(orgCode);
        })
        .map(rule -> {
            SchemaColumnRule columnRule = new SchemaColumnRule();
            BeanUtils.copyProperties(rule, columnRule);
            return columnRule;
        })
        .collect(Collectors.toList());

这里使用了Optional类来避免空指针异常，对于可能为空的列表，可以使用`Optional.ofNullable()`方法将其转换为Optional对象，然后使用`map()`方法进行转换或默认值设置。同时，使用lambda表达式可以更加简洁地实现函数式编程。