Develop Reference

How to properly handle comma inside a quoted string using opencsv?

I'm trying to read csv file that contains strings both quoted and not.
If string is quoted, it should save it's quote chars.
Beside that, if string contains comma, it should not be split.
I've tried multiple ways but nothing works as of now.
Current test data:
"field1 (with use of , we lose the other part)",some description
field2,"Dear %s, some text"
Getting 1st field of mapped bean
Expected result:
"field1 (with use of , we lose the other part)"
field2
Current result:
"field1 (with use of
field2
Here is the code:
public class CsvToBeanReaderTest {
#Test
void shouldIncludeDoubleQuotes() {
String testData =
"\"field1 (with use of , we lose the other part)\",some description\n"
+
"field2,\"Dear %s, some text\"";
RFC4180ParserBuilder rfc4180ParserBuilder = new RFC4180ParserBuilder();
rfc4180ParserBuilder.withQuoteChar(ICSVWriter.NO_QUOTE_CHARACTER);
ICSVParser rfc4180Parser = rfc4180ParserBuilder.build();
CSVReaderBuilder builder = new CSVReaderBuilder(new StringReader(testData));
CSVReader reader = builder
.withCSVParser(rfc4180Parser)
.build();
List<TestClass> result = new CsvToBeanBuilder<TestClass>(reader)
.withType(TestClass.class)
.withEscapeChar('\"')
.build()
.parse();
result.forEach(testClass -> System.out.println(testClass.getField1()));
}
private List<TestClass> readTestData(String testData) {
return new CsvToBeanBuilder<TestClass>(new StringReader(testData))
.withType(TestClass.class)
.withSeparator(',')
.withSkipLines(0)
.withIgnoreEmptyLine(true)
.build()
.parse();
}
public static final class TestClass {
#CsvBindByPosition(position = 0)
private String field1;
#CsvBindByPosition(position = 1)
private String description;
public String toCsvFormat() {
return String.join(",",
field1,
description);
}
public String getField1() {
return field1;
}
}
}
I've found out that if I comment or remove rfc4180ParserBuilder.withQuoteChar(ICSVWriter.NO_QUOTE_CHARACTER); the string will be parsed correctly, but I will lose the quote char which should not be lost. Is there any suggestions what can be done? (I would prefer not to switch on other csv libraries)

Replace a variable in a String

I am looking for a String Utils so that I can do something like this.
String input = "this is the $var on $date"
someUtil.evaluate(input, [var: "end", date: "11/11/11"])
output : this is the end on 11/11/11.
someUtil.evaluate(input, [var: "start", date: "10/10/10"])
output : this is the start on 10/10/10.

Use standard java MessageFormat, it is quite powerfull (read its class level JavaDoc)
Date endDate = new GregorialCalendar(2011, Calendar.NOVEMBER, 11).getTime();
...
MessageFormat.format(
"this is the {0} on {1,date,yy/MM/dd}",
new Object[]{"end", endDate});

Do you really need as incoming parameter that "array" ? If not, that you can implement as easy as it is ..
private static String replaceVarByVal(String toReplace,String var,String val){
return toReplace.replace(var, val);
}
(You can easy modify that to incom params arrays, but better should be eg. Map- key variable, value new value of the "placeholder" - $var)
Arrays variant:
private static String replaceVarByVal(String toReplace,String[] var,String[] val){
String toRet = toReplace;
//arrays logic problem
if(var.length != val.length){
return null;
}else{
for (int i = 0; i < var.length; i++) {
toRet = toRet.replace(var[i], val[i]);
}
}
return toRet;
}
Better variant with map:
private static String replaceVarByVal(String toReplace,Map<String, String> paramValsMap){
String toRet = toReplace;
for (Map.Entry<String, String> entry : paramValsMap.entrySet())
{
toRet=toRet.replace(entry.getKey(), entry.getValue());
}
return toRet;
}
(And that can be used universally for anything)

GreenDao whereOr and conditions adding in a loop

I need to add some or clauses to query. I need to do it in a loop.
StringTokenizer st = new StringTokenizer(symptoms, ",");
while(st.hasMoreTokens()){
qb.whereOr(Properties.Symptom.like("%" + st.nextToken() + "%"));
}
How I can add those or conditions properly, because this above is not working as expected. I want to add or for every symptom.

If you look at the documentation, you'll see that whereOr() takes an unbounded number of conditions. What you want to do is add them all at once in an array:
StringTokenizer st = new StringTokenizer(symptoms, ",");
ArrayList<WhereCondition> whereConditions = new ArrayList<WhereCondition>();
while(st.hasMoreTokens()){
whereConditions.add(Properties.Symptom.like("%" + st.nextToken() + "%"));
}
// Give the ArrayList an already allocated array to place its contents in.
WhereCondition[] conditionsArray = new WhereCondition[whereConditions.size()];
conditionsArray = whereConditions.toArray(conditionsArray);
qb.whereOr(conditionsArray);
It looks like the method call in the documentation takes two non-array WhereConditions and then an ellipsized argument, which accepts an array or an additional comma-separated list of objects. So you might have to do something like this to get it to work properly:
qb.whereOr(conditionsArray[0], conditionsArray[1], Arrays.copyOfRange(conditionsArray, 2, conditionsArray.length));
ADDENDUM: It looks like you're using APIs that don't match the documentation, possibly an older version of greenDAO. I wrote this solution based off the current documentation. I can't guarantee that it will work for you. I recommend updating if possible.

Try this:
StringTokenizer st = new StringTokenizer(symptoms, ",");
WhereCondition where = null;
while(st.hasMoreTokens()){
if (where != null) {
where = qb.or(where, Properties.Symptom.like("%" + st.nextToken() + "%"));
} else {
where = Properties.Symptom.like("%" + st.nextToken() + "%");
}
}
qb.where(where).list();

I had the same problem so I added my own method in an Util class to perform the same behavior when I have one or several WhereCondition in an array.
Here is my gateway method :
public static QueryBuilder whereOr(QueryBuilder queryBuilder, WhereCondition[] whereConditions){
if(whereConditions == null) return queryBuilder.where(null);
else if(whereConditions.length == 1) return queryBuilder.where(whereConditions[0]);
else return queryBuilder.whereOr(whereConditions[0], whereConditions[1], Arrays.copyOfRange(whereConditions, 2, whereConditions.length));
}
Use : Util.whereOr(queryBuilder, whereConditionsArray);
Default : Can't use the Builder Pattern from the QueryBuilder with this approach
(More later) Here, I share you some code which could spare you time when developping DAO methods.
public class QueryBuilderUtil {
public static final String EQ = "=?";
public static final String NOTEQ = "<>?";
public static final String LIKE = " LIKE ?";
public static final String GE = ">=?";
public static final String LE = "<=?";
public static final String GT = ">?";
public static final String LT = "<?";
public static QueryBuilder whereOrOnSamePropertyWithDifferentValues(QueryBuilder queryBuilder, Property property, String operation, String values, String separator) {
return whereOrOnSamePropertyWithDifferentValues(queryBuilder, property, operation, values.split(separator));
}
public static QueryBuilder whereOrOnSamePropertyWithDifferentValues(QueryBuilder queryBuilder, Property property, String operation, String[] values) {
WhereCondition[] whereConditions = new WhereCondition[values.length];
int i = 0;
for (String value : values) {
whereConditions[i++] = new WhereCondition.PropertyCondition(property, operation, value);
}
return whereOr(queryBuilder, whereConditions);
}
public static QueryBuilder whereOr(QueryBuilder queryBuilder, WhereCondition[] whereConditions) {
if (whereConditions == null) return queryBuilder.where(null);
else if (whereConditions.length == 1) return queryBuilder.where(whereConditions[0]);
else return queryBuilder.whereOr(whereConditions[0], whereConditions[1], Arrays.copyOfRange(whereConditions, 2, whereConditions.length));
}
}
With this class, you can perform a whereOr with the same property on multiples "values string" in one line. It was necessary to clean my code :). However you can only do simple operations like variables declared in the class.
Example :
public List<Block> loadAllByModId(String mods_id) {
synchronized (this) {
QueryBuilder<Block> queryBuilder = queryBuilder();
QueryBuilderUtil.whereOrOnSamePropertyWithDifferentValues(queryBuilder, Properties.ModId, QueryBuilderUtil.EQ, mods_id, ";");
query_list = queryBuilder.build();
}
Query<Block> query = query_list.forCurrentThread();
return query.list();
}
Hope it helps

Get string between an symbol

I am extracting a youtube video id from a youtube link. the list looks like this
http://www.youtube.com/watch?v=mmmc&feature=plcp
I want to get the mmmc only.
i used .replaceAll ?

Three ways:
Url parsing:
http://download.oracle.com/javase/6/docs/api/java/net/URL.html
URL url = new URL("http://www.youtube.com/watch?v=mmmc&feature=plcp");
url.getQuery(); // return query string.
Regular Expression
Examples here http://www.vogella.com/articles/JavaRegularExpressions/article.html
Tokenize
String s = "http://www.youtube.com/watch?v=mmmc&feature=plcp";
String arr[] = s.split("=");
String arr1[] = arr[1].split("&");
System.out.println(arr1[0]);

If you'd like to use regular expressions, this could be a solution:
Pattern p = Pattern
.compile("http://www.youtube.com/watch\\?v=([\\s\\S]*?)\\&feature=plcp");
Matcher m = p.matcher(youtubeLink);
if (m.find()) {
return m.group(1);
}
else{
throw new IllegalArgumentException("invalid youtube link");
}
Of course, this will only work if the feature will always be plcp, if not, you could simply remove that part or replace it with a wilcard as I did with mmmc

Edit: now i know what you are looking for i hope:
String url= "http://www.youtube.com/watch?v=mmmc&feature=plcp";
String search = "v=";
int index = url.indexOf(search);
int index2 = url.indexOf("&",index);
String found = url.substring(index+2,index2);
System.out.println(found);

Here's a generic solution (using Guava MapSplitter):
public final class UrlUtil {
/**
* Query string splitter.
*/
private static final MapSplitter PARAMS_SPLITTER = Splitter.on('&').withKeyValueSeparator("=");
/**
* Get param value in provided url for provided param.
*
* #param url Url to use
* #param param Param to use
* #return param value or null.
*/
public static String getParamVal(String url, String param)
{
if (url.contains("?")) {
final String query = url.substring(url.indexOf('?') + 1);
return PARAMS_SPLITTER.split(query).get(param);
}
return null;
}
public static void main(final String[] args)
{
final String url = "http://www.youtube.com/watch?v=mmmc&feature=plcp";
System.out.println(getParamVal(url, "v"));
System.out.println(getParamVal(url, "feature"));
}
}
Outputs:
mmmc
plcp

How to combine 2 java methods into one efficiently

I'm trying to create a validate java class that receives 4 inputs from an object passed as 1 from the requester. The class needs to convert float inputs to string and evaluate each input to meet a certain format and then throw exceptions complete with error message and code when it fails.
What I have is in two methods and would like to know if there is a better way to combine these two classes into one validate method for the main class to call. I don't seem to be able to get around using the pattern/matcher concept to insure the inputs are formatted correctly. Any help you can give would be very much appreciated.
public class Validator {
private static final String MoneyPattern ="^\\d{1,7}(\\.\\d{1,2})$" ;
private static final String PercentagePattern = "^\\d{1,3}\\.\\d{1,2}$";
private static final String CalendarYearPattern = "^20[1-9][0-9]$";
private int errorcode = 0;
private String errormessage = null;
public Validator(MyInput input){
}
private boolean verifyInput(){
String Percentage = ((Float) input.getPercentage().toString();
String Income = ((Float) input.getIncome().toString();
String PublicPlan = ((Float) input.getPublicPlan().toString();
String Year = ((Float) input.getYear();
try {
if (!doesMatch(Income, MoneyPattern)) {
errormessage = errormessage + "income,";
}
if (!doesMatch(PublicPlan, MoneyPattern)) {
errormessage = errormessage + "insurance plan,";
}
if (!doesMatch(Percentage, PercentagePattern)) {
errormessage = errormessage + "Percentage Plan,";
}
if (!doesMatch(Year, CalendarYearPattern)) {
errormessage = errormessage + "Year,";
}
} catch (Exception e){
errorcode = 111;
errormessage = e.getMessage();
}
}
private boolean doesMatch(String s, String pattern) throws Exception{
try {
Pattern p = Pattern.compile(pattern);
Matcher m = p.matcher(s);
if (!s.equals("")){
if(m.find()){
return true;
} else {
return false;
}
}else {
return false;
}
} catch (PatternSyntaxException pse){
errorcode = 111;
errormessage = pse.getMessage();
}
}
}

This code is borked from the word "go". You have a constructor into which you pass a MyInput reference, but there's no code in the ctor and no private data member to receive it. It looks like you expect to use input in your doesMatch() method, but it's a NullPointerException waiting to happen.
Your code doesn't follow the Sun Java coding standards; variable names should be lower case.
Why you wouldn't do that input validation in the ctor, when you actually receive the value, is beyond me. Perhaps you really meant to pass it into that verifyInput() method.
I would worry about correctness and readability before concerning myself with efficiency.
I'd have methods like this:
public boolean isValidMoney(String money) { // put the regex here }
public boolean isValidYear(String year) { // the regex here }
I think I'd prefer a real Money class to a String. There's no abstraction whatsoever.
Here's one bit of honesty:
private static final String CalendarYearPattern = "^20[1-9][0-9]$";
I guess you either don't think this code will still be running in the 22nd century or you won't be here to maintain it.

One way of doing this would be with DynamicBeans.
package com.acme.validator;
import java.util.HashMap;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.beanutils.PropertyUtils;
public class Validator {
//A simple optimisation of the pattern
private static final Pattern MoneyPattern = Pattern.compile("^\\d{1,7}(\\.\\d{1,2})$");
private static final Pattern PercentagePattern = Pattern.compile("^\\d{1,3}\\.\\d{1,2}$");
private static final Pattern CalendarYearPattern = Pattern.compile("^20[1-9][0-9]$");
public String Validator(MyInput input) {
String errormessage = "";
/*
* Setting these up as Maps.
* Ideally this would be a 'simple bean'
* but that goes beyond the scope of the
* original question
*/
Map<String,Pattern> patternMap = new HashMap<String,Pattern>();
patternMap.put("percentage", PercentagePattern);
patternMap.put("publicPlan", MoneyPattern);
patternMap.put("income", MoneyPattern);
patternMap.put("year", CalendarYearPattern);
Map<String,String> errorMap = new HashMap<String,String>();
errorMap.put("percentage", "Percentage Plan,");
errorMap.put("publicPlan", "insurance plan,");
errorMap.put("income", "income,");
errorMap.put("year", "Year,");
for (String key : patternMap.keySet()) {
try {
String match = ((Float) PropertyUtils.getSimpleProperty(input, key)).toString();
Matcher m = patternMap.get(key).matcher(match);
if ("".equals(match) || !m.find()) {
errormessage = errormessage + errorMap.get(key);
}
} catch (Exception e) {
errormessage = e.getMessage(); //since getMessage() could be null, you need to work out some way of handling this in the response
//don't know the point of the error code so remove this altogether
break; //Assume an exception trumps any validation failure
}
}
return errormessage;
}
}
I've made a few assumptions about the validation rules (for simplicity used 2 maps but you could also use a single map and a bean containing both the Pattern and the Message and even the 'error code' if that is important).
The key 'flaw' in your original setup and what would hamper the solution above, is that you are using 'year' as Float in the input bean.
(new Float(2012)).toString()
The above returns "2012.0". This will always fail your pattern. When you start messing about with the different types of objects potentially in the input bean, you may need to consider ensuring they are String at the time of creating the input bean and not, as is the case here, when they are retrieved.
Good Luck with the rest of your Java experience.