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package com.google.refine.commands.recon;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.StringWriter;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONWriter;
import com.google.refine.commands.Command;
import com.google.refine.expr.ExpressionUtils;
import com.google.refine.model.Column;
import com.google.refine.model.Project;
import com.google.refine.model.Row;
import com.google.refine.util.ParsingUtilities;
public class GuessTypesOfColumnCommand extends Command {
@Override
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
try {
Project project = getProject(request);
String columnName = request.getParameter("columnName");
String serviceUrl = request.getParameter("service");
response.setCharacterEncoding("UTF-8");
response.setHeader("Content-Type", "application/json");
JSONWriter writer = new JSONWriter(response.getWriter());
writer.object();
Column column = project.columnModel.getColumnByName(columnName);
if (column == null) {
writer.key("code"); writer.value("error");
writer.key("message"); writer.value("No such column");
} else {
List<TypeGroup> typeGroups = guessTypes(project, column, serviceUrl);
writer.key("code"); writer.value("ok");
writer.key("types"); writer.array();
for (TypeGroup tg : typeGroups) {
writer.object();
writer.key("id"); writer.value(tg.id);
writer.key("name"); writer.value(tg.name);
writer.key("score"); writer.value(tg.score);
writer.key("count"); writer.value(tg.count);
writer.endObject();
}
writer.endArray();
}
writer.endObject();
} catch (Exception e) {
respondException(response, e);
}
}
final static int SAMPLE_SIZE = 10;
/**
* Run relevance searches for the first n cells in the given column and
* count the types of the results. Return a sorted list of types, from most
* frequent to least.
*
* @param project
* @param column
* @return
* @throws JSONException, IOException
*/
protected List<TypeGroup> guessTypes(Project project, Column column, String serviceUrl)
throws JSONException, IOException {
Map<String, TypeGroup> map = new HashMap<String, TypeGroup>();
int cellIndex = column.getCellIndex();
List<String> samples = new ArrayList<String>(SAMPLE_SIZE);
Set<String> sampleSet = new HashSet<String>();
for (Row row : project.rows) {
Object value = row.getCellValue(cellIndex);
if (ExpressionUtils.isNonBlankData(value)) {
String s = value.toString().trim();
if (!sampleSet.contains(s)) {
samples.add(s);
sampleSet.add(s);
if (samples.size() >= SAMPLE_SIZE) {
break;
}
}
}
}
StringWriter stringWriter = new StringWriter();
try {
JSONWriter jsonWriter = new JSONWriter(stringWriter);
jsonWriter.object();
for (int i = 0; i < samples.size(); i++) {
jsonWriter.key("q" + i);
jsonWriter.object();
jsonWriter.key("query"); jsonWriter.value(samples.get(i));
jsonWriter.key("limit"); jsonWriter.value(3);
jsonWriter.endObject();
}
jsonWriter.endObject();
} catch (JSONException e) {
logger.error("Error constructing query", e);
}
String queriesString = stringWriter.toString();
try {
URL url = new URL(serviceUrl);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
{
connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
connection.setConnectTimeout(30000);
connection.setDoOutput(true);
DataOutputStream dos = new DataOutputStream(connection.getOutputStream());
try {
String body = "queries=" + ParsingUtilities.encode(queriesString);
dos.writeBytes(body);
} finally {
dos.flush();
dos.close();
}
connection.connect();
}
if (connection.getResponseCode() >= 400) {
InputStream is = connection.getErrorStream();
throw new IOException("Failed - code:"
+ Integer.toString(connection.getResponseCode())
+ " message: " + is == null ? "" : ParsingUtilities.inputStreamToString(is));
} else {
InputStream is = connection.getInputStream();
try {
String s = ParsingUtilities.inputStreamToString(is);
JSONObject o = ParsingUtilities.evaluateJsonStringToObject(s);
for (int i = 0; i < samples.size(); i++) {
String key = "q" + i;
if (!o.has(key)) {
continue;
}
JSONObject o2 = o.getJSONObject(key);
if (!(o2.has("result"))) {
continue;
}
JSONArray results = o2.getJSONArray("result");
int count = results.length();
for (int j = 0; j < count; j++) {
JSONObject result = results.getJSONObject(j);
double score = 1.0 / (1 + j); // score by each result's rank
JSONArray types = result.getJSONArray("type");
int typeCount = types.length();
for (int t = 0; t < typeCount; t++) {
Object type = types.get(t);
String typeID;
String typeName;
if (type instanceof String) {
typeID = typeName = (String) type;
} else {
typeID = ((JSONObject) type).getString("id");
typeName = ((JSONObject) type).getString("name");
}
double score2 = score * (typeCount - t) / typeCount;
if (map.containsKey(typeID)) {
TypeGroup tg = map.get(typeID);
tg.score += score2;
tg.count++;
} else {
map.put(typeID, new TypeGroup(typeID, typeName, score2));
}
}
}
}
} finally {
is.close();
}
}
} catch (IOException e) {
logger.error("Failed to guess cell types for load\n" + queriesString, e);
throw e;
}
List<TypeGroup> types = new ArrayList<TypeGroup>(map.values());
Collections.sort(types, new Comparator<TypeGroup>() {
@Override
public int compare(TypeGroup o1, TypeGroup o2) {
int c = Math.min(SAMPLE_SIZE, o2.count) - Math.min(SAMPLE_SIZE, o1.count);
if (c != 0) {
return c;
}
return (int) Math.signum(o2.score / o2.count - o1.score / o1.count);
}
});
return types;
}
static protected class TypeGroup {
String id;
String name;
int count;
double score;
TypeGroup(String id, String name, double score) {
this.id = id;
this.name = name;
this.score = score;
this.count = 1;
}
}
}