从csv生成树结构 [英] Generate tree structure from csv
问题描述
我已经把这个问题抓了一会儿。我基本上试图从一组CSV数据生成树层次结构。 CSV数据不一定是有序的。这类似如下：
I have scratched my head over this problem for a while now. I am basically trying to generate a tree hierarchy from a set of CSV data. The CSV data is not necessarily ordered. This is like something as follows:
Header: Record1,Record2,Value1,Value2
Row: A,XX,22,33
Row: A,XX,777,888
Row: A,YY,33,11
Row: B,XX,12,0
Row: A,YY,13,23
Row: B,YY,44,98
执行分组的方式尽可能灵活。最简单的分组方法是对Record1和Record2执行，Value1和Value2存储在Record2下，这样我们得到以下输出：
I am trying to make the way the grouping is performed as flexible as possible. The simplest for of grouping would to do it for Record1 and Record2 with the Value1 and Value2 stored under Record2 so that we get the following output:
Record1
Record2
Value1 Value2
p>
Which would be:
A
XX
22,33
777,888
YY
33,11
13,23
B
XX
12,0
YY
44,98
我现在将我的组设置存储在列表中 - 我不知道这是否阻碍了我的想法。此列表包含组的层次结构，例如：
I am storing my group settings in a List at present - which I don't know if this is hindering my thoughts. This list contains a hierarchy of the groups for example:
Record1 (SchemaGroup)
.column = Record1
.columns = null
.childGroups =
Record2 (SchemaGroup)
.column = Record1
.columns = Value1 (CSVColumnInformation), Value2 (CSVColumnInformation)
.childGroups = null
这样的代码如下：
private class SchemaGroup {
private SchemaGroupType type = SchemaGroupType.StaticText; // default to text
private String text;
private CSVColumnInformation column = null;
private List<SchemaGroup> childGroups = new ArrayList<SchemaGroup>();
private List<CSVColumnInformation> columns = new ArrayList<CSVColumnInformation>();
}
private enum SchemaGroupType {
/** Allow fixed text groups to be added */
StaticText,
/** Related to a column with common value */
ColumnGroup
}
努力为此产生一个算法，试图想到使用的底层结构。目前我使用自己的包装类来解析CSV：
I am stuggling producing an algorithm for this, trying to think of the underlying structure to use. At present I am parsing the CSV top to bottom, using my own wrapper class:
CSVParser csv = new CSVParser(content);
String[] line;
while((line = csv.readLine()) != null ) {
...
}
我只是想开始我的编码脑。
I am just trying to kick start my coding brain.
任何想法？
推荐答案
这里是junit形式的基本工作解决方案（没有断言），通过使用 google-guava collections 。代码是不言自明的，而不是文件io使用csv库读取csv。这应该给你的基本想法。
Here is the basic working solution in the form of junit (no assertions though) simplified by using google-guava collections. The code is self-explanatory and instead of file io you use csv libraries for reading the csv. This should give you the basic idea.
import java.io.File;
import java.io.IOException;
import java.util.Collection;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import org.junit.Test;
import com.google.common.base.Charsets;
import com.google.common.base.Splitter;
import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.Iterables;
import com.google.common.collect.Multimap;
import com.google.common.collect.Sets;
import com.google.common.io.Files;
public class MyTest
{
@Test
public void test1()
{
List<String> rows = getAllDataRows();
Multimap<Records, Values> table = indexData(rows);
printTree(table);
}
private void printTree(Multimap<Records, Values> table)
{
Set<String> alreadyPrintedRecord1s = Sets.newHashSet();
for (Records r : table.keySet())
{
if (!alreadyPrintedRecord1s.contains(r.r1))
{
System.err.println(r.r1);
alreadyPrintedRecord1s.add(r.r1);
}
System.err.println("\t" + r.r2);
Collection<Values> allValues = table.get(r);
for (Values v : allValues)
{
System.err.println("\t\t" + v.v1 + " , " + v.v2);
}
}
}
private Multimap<Records, Values> indexData(List<String> lines)
{
Multimap<Records, Values> table = ArrayListMultimap.create();
for (String row : lines)
{
Iterable<String> split = Splitter.on(",").split(row);
String[] data = Iterables.toArray(split, String.class);
table.put(new Records(data[0], data[1]), new Values(data[2], data[3]));
}
return table;
}
private List<String> getAllDataRows()
{
List<String> lines = Collections.emptyList();
try
{
lines = Files.readLines(new File("C:/test.csv"), Charsets.US_ASCII);
}
catch (IOException e)
{
e.printStackTrace();
}
lines.remove(0);// remove header
return lines;
}
}
public class Records
{
public final String r1, r2;
public Records(final String r1, final String r2)
{
this.r1 = r1;
this.r2 = r2;
}
@Override
public int hashCode()
{
final int prime = 31;
int result = 1;
result = prime * result + ((r1 == null) ? 0 : r1.hashCode());
result = prime * result + ((r2 == null) ? 0 : r2.hashCode());
return result;
}
@Override
public boolean equals(final Object obj)
{
if (this == obj)
{
return true;
}
if (obj == null)
{
return false;
}
if (!(obj instanceof Records))
{
return false;
}
Records other = (Records) obj;
if (r1 == null)
{
if (other.r1 != null)
{
return false;
}
}
else if (!r1.equals(other.r1))
{
return false;
}
if (r2 == null)
{
if (other.r2 != null)
{
return false;
}
}
else if (!r2.equals(other.r2))
{
return false;
}
return true;
}
@Override
public String toString()
{
StringBuilder builder = new StringBuilder();
builder.append("Records1and2 [r1=").append(r1).append(", r2=").append(r2).append("]");
return builder.toString();
}
}
public class Values
{
public final String v1, v2;
public Values(final String v1, final String v2)
{
this.v1 = v1;
this.v2 = v2;
}
@Override
public int hashCode()
{
final int prime = 31;
int result = 1;
result = prime * result + ((v1 == null) ? 0 : v1.hashCode());
result = prime * result + ((v2 == null) ? 0 : v2.hashCode());
return result;
}
@Override
public boolean equals(final Object obj)
{
if (this == obj)
{
return true;
}
if (obj == null)
{
return false;
}
if (!(obj instanceof Values))
{
return false;
}
Values other = (Values) obj;
if (v1 == null)
{
if (other.v1 != null)
{
return false;
}
}
else if (!v1.equals(other.v1))
{
return false;
}
if (v2 == null)
{
if (other.v2 != null)
{
return false;
}
}
else if (!v2.equals(other.v2))
{
return false;
}
return true;
}
@Override
public String toString()
{
StringBuilder builder = new StringBuilder();
builder.append("Values1and2 [v1=").append(v1).append(", v2=").append(v2).append("]");
return builder.toString();
}
}
这篇关于从csv生成树结构的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
