问题描述
我有两张地图如下:
Map<String, Record> sourceRecords; Map<String, Record> targetRecords;
我想获得与每个地图不同的键.即
I want to get the keys differ from each of the maps.i.e.
- 它显示 sourceRecords 中可用但 targetRecords 中不可用的映射键.
- 它显示 targetRecords 中可用但 sourceRecords 中不可用的映射键.
我是这样做的:
Set<String> sourceKeysList = new HashSet<String>(sourceRecords.keySet()); Set<String> targetKeysList = new HashSet<String>(targetRecords.keySet()); SetView<String> intersection = Sets.intersection(sourceKeysList, targetKeysList); Iterator it = intersection.iterator(); while (it.hasNext()) { Object object = (Object) it.next(); System.out.println(object.toString()); } SetView<String> difference = Sets.symmetricDifference(sourceKeysList, targetKeysList); ImmutableSet<String> immutableSet = difference.immutableCopy();
编辑
if(sourceKeysList.removeAll(targetKeysList)){ //distinct sourceKeys Iterator<String> it1 = sourceKeysList.iterator(); while (it1.hasNext()) { String id = (String) it1.next(); String resultMessage = "This ID exists in source file but not in target file"; System.out.println(resultMessage); values = createMessageRow(id, resultMessage); result.add(values); } } if(targetKeysList.removeAll(sourceKeysList)){ //distinct targetKeys Iterator<String> it1 = targetKeysList.iterator(); while (it1.hasNext()) { String id = (String) it1.next(); String resultMessage = "This ID exists in target file but not in source file"; System.out.println(resultMessage); values = createMessageRow(id, resultMessage); result.add(values); } }
我能够找到公共键,但不能找到不同的键.请帮忙.
I am able to find the common keys but not distinct keys. Please help.
推荐答案
集合也允许您删除元素.
如果生成帮助"集对您来说不是问题(因为条目太多;那么:
If generating "helper" sets is not a problem for you (because of too many entries; what about:
Set<String> sources = get a copy of all source entries Set<String> targets = get a copy of all source entries
然后:
sources.removeAll(targets) ... leaves only entries in sources that are only in sources, not in target
而
sources.retainAll(targets) ... leaves only entries that are in both sets
您可以从这里开始工作......
You can work your way from here ...