我正在尝试合并2个已获取json URL数据的数组，这2个url具有1个共享字段，称为“ bay_id”，该字段可匹配3080个项目。 URL 1具有3080数据，URL 2具有7100数据。我确实比较了URL 1中的“ bay_id”在URL 2中是否具有相同的“ bay_id”，然后进行了合并。我的for循环遇到的问题是，它为所有索引设置了相同的“ bay_id”。除了名为Post的myClass外，所有所需字段都具有setter和getter方法。 我的代码是：
for (int i = 0; i < url_1.length; i++) {
for (int j = 0; j < url_2.length; j++) {
if (url_2[j].getBayId_2().equals(url_1[i].getBayId_1()) ) {
for (int k = 0; k < mergedURLs.length; k++) {
mergedURLs[k].setBayId_1(url_1[i].getBayId_1());
mergedURLs[k].setStatus(url_1[i].getStatus());
mergedURLs[k].setLat(url_1[i].getLat());
mergedURLs[k].setLon(url_1[i].getLon());
mergedURLs[k].setBayId_2(url_2[j].getBayId_2());
//and so on for all the fields
}//-------End if statment
}//------End for loop url_2
}//-------end for loop url_1
}//-------end for loop
for (int z = 0; z < mergedURLs.length; z++) {
System.out.println("New bay_id" + mergedURLs[z].getBayId_1());
}
答案 0 :(得分：0)
这是一种执行此操作的方法。我创建了一个名为MyUrl的测试类，它代表数组（urls1和urls2）和合并数组中的对象。这个MyUrl类实现了java.lang.Comparable接口-用于对url1数组进行排序（更多详细信息，请参见下文）。
合并过程：我假设urls2数组比urls1具有更多数据。首先，我创建了一个空ArrayList<MyUrl>，它将包含所有URL-合并的URL。然后 sort urls1数组-这是通过urls1中的bayId用urls2搜索Arrays.binarySearch数组-urls2方法是使用。
现在，在for循环中迭代urls1，并在bayId中搜索每个urls2（bayId）的匹配项。一旦找到匹配的ArrayList，数据将合并并存储在urls2中，否则仅存储ArrayList数据。到for循环结束时，ArrayList将具有合并的数据。
下面的示例程序可以编译并运行。查看输入数组中的数据以及合并后的MyUrl的打印输出。匹配并合并的import java.util.*;
public class CompareAndMerge {
// Some test data: two sets of url data. One with lesser urls1 and
// the other usrls2. Note there are some matching bayIds in both arrays.
private static MyUrl [] urls1 = {new MyUrl("abc", "yes"), new MyUrl("xyz", "no"),
new MyUrl("url", "true"), new MyUrl("lmn", "false")};
private static MyUrl [] urls2 = {new MyUrl("abc", "yes"), new MyUrl("xyz", "no"),
new MyUrl("cat", "else"), new MyUrl("rat", "if"),
new MyUrl("url", "true"), new MyUrl("lmn", "false")};
public static void main(String [] args) {
// The urls1 array is sorted by bayId to allow a binary search -
// the searching of array by bayId.
// Also, see the method getMatchingUrl()
Arrays.sort(urls1, null); // null indicates the elements implement comparable
// The list is to store the merged urls from bouth the arrays
List<MyUrl> merged = new ArrayList<>();
// Iterate over the urls2 (the array with more elements) and store
// the merged data in the list. The data is merged when there
// is a match with bayId otherwise just the urls2 data is stored.
for (MyUrl url2 : urls2) {
MyUrl url1 = getMatchingUrl(url2);
if (url1 == null) {
// no bayId match found
// store the url2 to merged urls
merged.add(url2);
}
else {
// found a matching bayId in urls1
// merge the url1 to url2 data
// for example: url2.setBayId2(url1.getBayId2()); etc.
url2.setMerged("MERGED");
merged.add(url2);
}
}
// Result shows matching bayId's urls are merged.
// The output has all the urls from both the arrays.
System.out.println(merged);
}
private static MyUrl getMatchingUrl(MyUrl url2) {
int urls1Index = Arrays.binarySearch(urls1, url2, null); // null indicates comparable elements
if (urls1Index < 0) {
return null;
}
return urls1[urls1Index];
}
}
class MyUrl implements Comparable<MyUrl> {
private String bayId;
private String status;
private String merged;
public MyUrl(String s1, String s2) {
bayId = s1;
status = s2;
}
public void setBayId(String s) {
bayId = s;
}
public String getBayId() {
return bayId;
}
public void setStatus(String s) {
status = s;
}
public String getStatus() {
return status;
}
public void setMerged(String s) {
merged = s;
}
@Override public String toString() {
return bayId + ":" + status + ":" + merged;
}
/*
* Implemented method of java.lang.Comparable
*/
@Override public int compareTo(MyUrl url) {
return this.bayId.compareTo(url.getBayId());
}
}
具有“ MERGED”标志。
示例代码：
hid.node