list<String>生成Supplier<list<String>>

可以使用Stream的map方法将List<String>转换为Supplier<List<String>>，示例代码如下：

List<String> list = Arrays.asList("a", "b", "c");
Supplier<List<String>> supplier = () -> new ArrayList<>(list);
List<Supplier<List<String>>> supplierList = Collections.singletonList(supplier);

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();
}

public class PageHelperUtil { public static <T> Page<T> startPage(PageSortInterface pageSort, Supplier<List<T>> supplier) { PageHelper.startPage(pageSort.getPageNum(), pageSort.getPageSize(), pageSort.getSort() + " " + pageSort.getOrder()); List<T> list = supplier.get(); PageInfo<T> pageInfo = new PageInfo<>(list); Page<T> page = new Page<>(); page.setContent(list); page.setTotal(pageInfo.getTotal()); page.setPageNum(pageInfo.getPageNum()); page.setPageSize(pageInfo.getPageSize()); page.setSort(pageSort.getSort()); page.setOrder(pageSort.getOrder()); return page; } }如果是有条件的查询分页，该如何修改？

如果是有条件的查询分页，可以在 `startPage` 方法中增加一个参数，用于传递查询条件，然后在 `supplier` 中根据条件进行查询，例如：

public static <T> Page<T> startPage(PageSortInterface pageSort, Supplier<List<T>> supplier, Object condition) {
    PageHelper.startPage(pageSort.getPageNum(), pageSort.getPageSize(), pageSort.getSort() + " " + pageSort.getOrder());
    List<T> list = supplier.get(condition);
    PageInfo<T> pageInfo = new PageInfo<>(list);
    Page<T> page = new Page<>();
    page.setContent(list);
    page.setTotal(pageInfo.getTotal());
    page.setPageNum(pageInfo.getPageNum());
    page.setPageSize(pageInfo.getPageSize());
    page.setSort(pageSort.getSort());
    page.setOrder(pageSort.getOrder());
    return page;
}

在 `supplier` 中接收条件参数，例如：

public List<User> getUsersByCondition(Map<String, Object> condition) {
    return userDao.getUsersByCondition(condition);
}

这样就可以根据条件进行分页查询了。