List<Integer> orders = sysTokenIterationTops.stream().map(SysTokenIterationTop::getFdTopOrder).filter(Objects::nonNull).collect(Collectors.toList()); 这段代码是获得sysTokenIterationTops这个list对象中toporder属性，我现在需要这个里面最大的元素，且防止判空

好，你可以使用Java 8的Stream API来实现这个功能。可以将过滤和获取最大值的操作链式调用，代码如下：

Optional<Integer> maxOrder = sysTokenIterationTops.stream()
        .map(SysTokenIterationTop::getFdTopOrder)
        .filter(Objects::nonNull)
        .max(Integer::compareTo);

首先通过`map()`方法将`SysTokenIterationTop`对象转换为其`fdTopOrder`属性值，然后使用`filter()`方法过滤掉为`null`的元素。接着使用`max()`方法获取最大值，`max()`方法返回一个`Optional`对象，防止`null`值的情况发生。最后你可以通过`Optional`对象的方法获得最大值，代码如下：

if (maxOrder.isPresent()) {
    Integer max = maxOrder.get();
    // do something with max
}

其中`isPresent()`方法用于判断是否存在最大值，`get()`方法用于获取最大值。

相关问题

if (sysTokenIterationTops.size() > 0) { List<Integer> orders = sysTokenIterationTops.stream().map(SysTokenIterationTop::getFdTopOrder).filter(Objects::nonNull).collect(Collectors.toList()); }具体的是这个，再优化下

你可以进一步优化这段代码，使其更加简洁和高效。可以使用`Optional`类的`map()`方法来实现获取最大值，代码如下：

Integer maxOrder = sysTokenIterationTops.stream()
        .map(SysTokenIterationTop::getFdTopOrder)
        .filter(Objects::nonNull)
        .max(Integer::compareTo)
        .orElse(null);

这段代码与之前的代码相比，使用了`Optional`类的`map()`方法来获取最大值，而不是先将结果转换为`List`对象，再获取最大值。这样可以避免创建不必要的`List`对象，提高代码的效率。最后使用`orElse(null)`方法来处理`null`值的情况，如果最大值不存在则返回`null`。

所以，最终的代码如下：

Integer maxOrder = sysTokenIterationTops.stream()
        .map(SysTokenIterationTop::getFdTopOrder)
        .filter(Objects::nonNull)
        .max(Integer::compareTo)
        .orElse(null);

if (maxOrder != null) {
    // do something with maxOrder
}

其中`sysTokenIterationTops`是你需要获取最大值的`List`对象，`SysTokenIterationTop`是`sysTokenIterationTops`中元素的类型，`getFdTopOrder()`是`SysTokenIterationTop`中获取`fdTopOrder`属性的方法。

List<DataPermissionSchemaEo> dataPermissionSchemaEoList = comDataComponent.getDataPermissionSchemaList(); List<SchemaRowRuleEo> schemaRowRuleList = comDataComponent.getSchemaRowRuleList(); List<SchemaColumnRuleEo> schemaColumnRuleList = comDataComponent.getSchemaColumnRuleList(); //设置行权限 根据用户id和用户组织去获取 List<SchemaRowRule> userRowRuleList = schemaRowRuleList.stream() .filter(schemaRowRuleEo -> { List<String> userList = JSONObject.parseArray(schemaRowRuleEo.getRowPermissionUserList(), String.class); List<String> orgList = JSONObject.parseArray(schemaRowRuleEo.getRowPermissionOrgList(), String.class); return userList.contains(userUid) || orgList.contains(orgCode) || userList.contains(WILDCARD) || orgList.contains(WILDCARD); }) .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 -> JSONObject.parseArray(userListStr, String.class)) .orElse(Collections.emptyList()); List<String> orgList = Optional.ofNullable(rule.getColumnPermissionOrgList()) .map(orgListStr -> JSONObject.parseArray(orgListStr, String.class)) .orElse(Collections.emptyList()); return userList.contains(userUid) || orgList.contains(orgCode) || userList.contains(WILDCARD) || orgList.contains(WILDCARD); }) .map(rule -> { SchemaColumnRule columnRule = new SchemaColumnRule(); BeanUtils.copyProperties(rule, columnRule); return columnRule; }) .collect(Collectors.toList()); List<DataPermissionSchema> dataPermissionSchemaList = dataPermissionSchemaEoList.stream().map(dataPermissionSchemaEo -> { List<SchemaRowRule> schemaRowRules = userRowRuleList.stream() .filter(schemaRule -> dataPermissionSchemaEo.getDatabaseCode().equals(schemaRule.getDatabaseCode()) && dataPermissionSchemaEo.getSchemaCode().equals(schemaRule.getSchemaCode())) .collect(Collectors.toList()); List<SchemaColumnRule> schemaColumnRules = userColumnRuleList.stream() .filter(schemaRule -> dataPermissionSchemaEo.getDatabaseCode().equals(schemaRule.getDatabaseCode()) && dataPermissionSchemaEo.getSchemaCode().equals(schemaRule.getSchemaCode())) .collect(Collectors.toList()); if(!schemaRowRules.isEmpty() || !schemaColumnRules.isEmpty()) { DataPermissionSchema dataPermissionSchema = new DataPermissionSchema(); dataPermissionSchema.setDatabaseCode(dataPermissionSchemaEo.getDatabaseCode()); dataPermissionSchema.setSchemaCode(dataPermissionSchemaEo.getSchemaCode()); dataPermissionSchema.setSchemaRowRuleList(schemaRowRules); dataPermissionSchema.setSchemaColumnRuleList(schemaColumnRules); return dataPermissionSchema; } return null; }).filter(Objects::nonNull).collect(Collectors.toList());把这段代码改造成每个用户拥有的行权限和列权限

可以将该代码封装成一个方法，接收用户ID和组织代码作为参数，返回该用户拥有的行权限和列权限，代码如下：

public List<DataPermissionSchema> getUserDataPermissionSchema(String userUid, String orgCode) {
    List<DataPermissionSchemaEo> dataPermissionSchemaEoList = comDataComponent.getDataPermissionSchemaList();
    List<SchemaRowRuleEo> schemaRowRuleList = comDataComponent.getSchemaRowRuleList();
    List<SchemaColumnRuleEo> schemaColumnRuleList = comDataComponent.getSchemaColumnRuleList();

    // 获取用户行权限
    List<SchemaRowRule> userRowRuleList = schemaRowRuleList.stream()
            .filter(schemaRowRuleEo -> {
                List<String> userList = JSONObject.parseArray(schemaRowRuleEo.getRowPermissionUserList(), String.class);
                List<String> orgList = JSONObject.parseArray(schemaRowRuleEo.getRowPermissionOrgList(), String.class);
                return userList.contains(userUid) || orgList.contains(orgCode) || userList.contains(WILDCARD) || orgList.contains(WILDCARD);
            })
            .map(schemaRowRuleEo -> {
                SchemaRowRule schemaRowRule = new SchemaRowRule();
                BeanUtils.copyProperties(schemaRowRuleEo, schemaRowRule);
                return schemaRowRule;
            })
            .collect(Collectors.toList());

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

    // 获取用户权限所在的数据权限模板
    List<DataPermissionSchema> dataPermissionSchemaList = dataPermissionSchemaEoList.stream().map(dataPermissionSchemaEo -> {
        List<SchemaRowRule> schemaRowRules = userRowRuleList.stream()
                .filter(schemaRule -> dataPermissionSchemaEo.getDatabaseCode().equals(schemaRule.getDatabaseCode())
                        && dataPermissionSchemaEo.getSchemaCode().equals(schemaRule.getSchemaCode()))
                .collect(Collectors.toList());
        List<SchemaColumnRule> schemaColumnRules = userColumnRuleList.stream()
                .filter(schemaRule -> dataPermissionSchemaEo.getDatabaseCode().equals(schemaRule.getDatabaseCode())
                        && dataPermissionSchemaEo.getSchemaCode().equals(schemaRule.getSchemaCode()))
                .collect(Collectors.toList());
        if(!schemaRowRules.isEmpty() || !schemaColumnRules.isEmpty()) {
            DataPermissionSchema dataPermissionSchema = new DataPermissionSchema();
            dataPermissionSchema.setDatabaseCode(dataPermissionSchemaEo.getDatabaseCode());
            dataPermissionSchema.setSchemaCode(dataPermissionSchemaEo.getSchemaCode());
            dataPermissionSchema.setSchemaRowRuleList(schemaRowRules);
            dataPermissionSchema.setSchemaColumnRuleList(schemaColumnRules);
            return dataPermissionSchema;
        }
        return null;
    }).filter(Objects::nonNull).collect(Collectors.toList());

    return dataPermissionSchemaList;
}