英文:
Java 8 how to simplify for loop with lambda expressions
问题
我有这个方法在我的代码中，需要使用Java 8表达式来简化和减少代码行数。Lambda可以用于这个，但似乎没有一个列表作为输入是不可能的。
我尝试过使用resourceUsages.forEach(resourceUsages.resource-> do something);，但没有列表作为输入似乎是不可能的。
有没有简化这段代码的方法？
英文:
I have this method in my code and need o simplify and reduce lines by using java 8 expressions.
Lambda can be used for this but it seems impossible without a list as input.
public ResourceUsage[] filterResourceUsages(ResourceUsage[] resourceUsages, int role, int includeResourceType)
throws SpiderException
{
ArrayList<ResourceUsage> filteredResourceUsages = new ArrayList<>();
String[] ids = new String[resourceUsages.length];
for (int i = 0; i < resourceUsages.length; i++)
{
ids[i] = resourceUsages[i].resource;
}
ResourceData[] resourceData = resourceToolkitAdapter.getData(ids);
for (int i = 0; i < resourceData.length; i++)
{
if (resourceUsages[i].role == role && resourceData[i].basic.type == includeResourceType)
{
filteredResourceUsages.add(resourceUsages[i]);
}
}
return filteredResourceUsages.toArray(new ResourceUsage[filteredResourceUsages.size()]);
}
I have tried using resourceUsages.forEach(resourceUsages.resource-> do something); but without list as input it seems impossible.
Is there any way to simplify this code?
答案1
得分: 7
以下是原始的代码片段及其翻译部分：
// 这是原始的数组和批处理解决方案：
public ResourceUsage[] filterResourceUsages(ResourceUsage[] resourceUsages, int role, int includeResourceType)
throws SpiderException {
// 将资源使用对象中的资源名称提取到一个字符串数组中
String[] ids = Stream.of(resourceUsages)
.map(ResourceUsage::getResource)
.toArray(String[]::new);
// 使用资源工具适配器获取资源数据，并将其映射到资源ID上
Map<String, ResourceData> resourceDataMap = Stream.of(resourceToolkitAdapter.getData(ids))
.collect(Collectors.toMap(ResourceData::id, Function.identity()));
// 过滤资源使用对象的数组，根据角色和包括的资源类型
return Stream.of(resourceUsages)
.filter(usage -> usage.role == usage) // 这里可能需要修正，根据实际逻辑
.filter(resourceDataMap::containsKey)
.filter(usage -> resourceDataMap.get(usage.resource).basic.type == includeResourceType)
.toArray(ResourceUsage[]::new);
}
希望这个翻译对您有所帮助。
英文:
here is the origin arrays and batch solution:
public ResourceUsage[] filterResourceUsages(ResourceUsage[] resourceUsages, int role, int includeResourceType)
throws SpiderException {
String[] ids = Stream.of(resourceUsages)
.map(ResourceUsage::getResource)
.toArray(String[]::new);
Map<String, ResourceData> resourceDataMap = Stream.of(resourceToolkitAdapter.getData(ids))
.collect(Collectors.toMap(ResourceData::id, Function.identity()));
return Stream.of(resourceUsages)
.filter(usage -> usage.role == usage)
.filter(resourceDataMap::containsKey)
.filter(usage -> resourceDataMap.get(usage.resource).basic.type == includeResourceType)
.toArray(ResourceUsage[]::new);
}
答案2
得分: 3
你可以像这样使用数组：
Arrays.stream(resourceUsages)
.forEach(e -> System.out.print(e));
英文:
You can do like this with arrays
Arrays.stream(resourceUsages)
.forEach(e->System.out.print(e));
答案3
得分: 2
最好使用 List<ResourceUsage> 而不是数组。
我也会假设逐个调用 resourceToolkitAdapter.getData() 对每个资源而言是可以的，而不是批量操作。
结果将类似于以下内容：
public List<ResourceUsage> filterResourceUsages(List<ResourceUsage> resourceUsages, int role, int includeResourceType)
throws SpiderException
{
return resourceUsages.stream()
.filter(r -> r.role == role)
.filter(r -> resourceToolkitAdapter.getData(r.resource).basic.type == includeResourceType)
.collect(Collectors.toList());
}
英文:
It's best if you use List<ResourceUsage> rather than arrays.
I'm also going to pretend it's ok to call resourceToolkitAdapter.getData() on each resource in turn, rather than in bulk.
The result will be something like so:
public List<ResourceUsage> filterResourceUsages(List<ResourceUsage> resourceUsages, int role, int includeResourceType)
throws SpiderException
{
return resourceUsages.stream()
.filter(r->r.role == role)
.filter(r->resourceToolkitAdapter.getData(r.resource).basic.type == includeResourceType)
.collect(Collectors.toList());
}
答案4
得分: 2
I assume that resourceToolkitAdapter.getData() should be called with a batch of ids.
我认为应该使用一批 ID 调用 resourceToolkitAdapter.getData()。
英文:
Opposed to the answer of Matthew, I assume that resourceToolkitAdapter.getData() should be called with a batch of ids.
public ResourceUsage[] filterResourceUsages(ResourceUsage[] resourceUsages, int role, int includeResourceType)
throws SpiderException
{
ResourceData[] resourceData = resourceToolkitAdapter.getData(
Arrays.stream(resourceUsages)
.map(r -> r.resource)
.toArray(String[]::new)
);
return IntStream
.range(0, resourceData.length)
.filter(i -> resourceUsages[i].role == role )
.filter(i -> resourceData[i].basic.type == includeResourceType)
.mapToObj(i -> resourceUsages[i])
.toArray(ResourceUsage[]::new);
}
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论