如何在java 8中迭代JSONArray [英] How to iterate over a JSONArray in java 8
本文介绍了如何在java 8中迭代JSONArray的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有以下代码,它使用 for循环
来迭代 JSONArray
中的元素。
I have the following code which is using a for loop
to iterate over the elements in a JSONArray
.
import org.apache.log4j.Logger;
import org.json.JSONArray;
import org.json.JSONObject;
import java.util.stream.IntStream;
public class Pmt {
private String[] patchInformation_svnRevisionpublic;
private final Logger logger = Logger.getLogger(Pmt.class.getName());
private static final String COMMITS_IN_PATCH_IDENTIFIER = "patchInformation_svnRevisionpublic"; //key used to identify the commits in a patch from JSON response received from PMT
private static final String KEY_STRING = "name";
private static final String VALUE_STRING = "value";
public String[] getPublicGitCommitHashes(JSONArray jsonArray) {
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = (JSONObject) jsonArray.get(i);
String tempName = (String) jsonObject.get(KEY_STRING);
if (tempName.equals(COMMITS_IN_PATCH_IDENTIFIER)) {
JSONArray tempCommitsJSONArray = (JSONArray) jsonObject.get(VALUE_STRING);
//initializing the patchInformation_svnRevisionpublic array
patchInformation_svnRevisionpublic = new String[tempCommitsJSONArray.length()];
// for ommiting the white spaces at the begingin and end of the commits
IntStream.range(0, tempCommitsJSONArray.length()).forEach(j -> patchInformation_svnRevisionpublic[j] = ((String) tempCommitsJSONArray.get(j)).trim());
logger.info(" The commits hashes obtained from WSO2 PMT are successfully saved to an array");
System.out.println("The commit Ids are");
// for printing all the commits ID associated with a patch
IntStream.range(0, patchInformation_svnRevisionpublic.length).mapToObj(i1 -> patchInformation_svnRevisionpublic[i1]).forEach(System.out::println);
System.out.println();
break;
}
}
//to prevent from internaal representation by returning referecnce to mutable object
String clonedPatchInformation_svnRevisionpublic[] = patchInformation_svnRevisionpublic.clone();
return clonedPatchInformation_svnRevisionpublic;
}
}
如何使用<$ c中的新功能$ c> Java 8 如 streams API
或 forEach
执行相同的任务。在此先感谢
How do I use the new features in Java 8
like streams API
or forEach
to perform the same task. Thanks in advance
推荐答案
这相当于Java 8流API中的代码或代码。不是100%等价,但你可以得到主要想法。
This is equivalent of or code in Java 8 stream API. Not 100% equivalent, but you can get the main idea.
private static final String COMMITS_IN_PATCH_IDENTIFIER = "patchInformation_svnRevisionpublic"; //key used to identify the commits in a patch from JSON response received from PMT
private static final String KEY_STRING = "name";
private static final String VALUE_STRING = "value";
public List<String> getCommitIds (JSONArray array) {
return arrayToStream(array)
.map(JSONObject.class::cast)
.filter(o -> o.get(KEY_STRING).equals(COMMITS_IN_PATCH_IDENTIFIER))
.findFirst()
.map(o -> (JSONArray) o.get(VALUE_STRING))
.map(Main::arrayToStream)
.map(commits ->
commits.map(Object::toString)
.map(String::trim)
.collect(Collectors.toList())
)
.orElseGet(Collections::emptyList);
}
@Nonnull
private static Stream<Object> arrayToStream(JSONArray array) {
return StreamSupport.stream(array.spliterator(), false);
}
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