Develop Reference

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 check if the subdomain is also from same domain using java

i have a list of url's i need to filter specific domain and subdomain. say i have some domains like
http://www.example.com
http://test.example.com
http://test2.example.com
I need to extract urls which from domain example.com.

Working on project that required me to determine if two URLs are from the same sub domain (even when there are nested domains). I worked up a modification from the guide above. This holds out pretty well thus far:
public static boolean isOneSubdomainOfTheOther(String a, String b) {
try {
URL first = new URL(a);
String firstHost = first.getHost();
firstHost = firstHost.startsWith("www.") ? firstHost.substring(4) : firstHost;
URL second = new URL(b);
String secondHost = second.getHost();
secondHost = secondHost.startsWith("www.") ? secondHost.substring(4) : secondHost;
/*
Test if one is a substring of the other
*/
if (firstHost.contains(secondHost) || secondHost.contains(firstHost)) {
String[] firstPieces = firstHost.split("\\.");
String[] secondPieces = secondHost.split("\\.");
String[] longerHost = {""};
String[] shorterHost = {""};
if (firstPieces.length >= secondPieces.length) {
longerHost = firstPieces;
shorterHost = secondPieces;
} else {
longerHost = secondPieces;
shorterHost = firstPieces;
}
//int longLength = longURL.length;
int minLength = shorterHost.length;
int i = 1;
/*
Compare from the tail of both host and work backwards
*/
while (minLength > 0) {
String tail1 = longerHost[longerHost.length - i];
String tail2 = shorterHost[shorterHost.length - i];
if (tail1.equalsIgnoreCase(tail2)) {
//move up one place to the left
minLength--;
} else {
//domains do not match
return false;
}
i++;
}
if (minLength == 0) //shorter host exhausted. Is a sub domain
return true;
}
} catch (MalformedURLException ex) {
ex.printStackTrace();
}
return false;
}
Figure I'd leave it here for future reference of a similar problem.

I understand you are probably looking for a fancy solution using URL class or something but it is not required. Simply think of a way to extract "example.com" from each of the urls.
Note: example.com is essentially a different domain than say example.net. Thus extracting just "example" is technically the wrong thing to do.
We can divide a sample url say:
http://sub.example.com/page1.html
Step 1: Split the url with delimiter " / " to extract the part containing the domain.
Each such part may be looked at in form of the following blocks (which may be empty)
[www][subdomain][basedomain]
Step 2: Discard "www" (if present). We are left with [subdomain][basedomain]
Step 3: Split the string with delimiter " . "
Step 4: Find the total number of strings generated from the split. If there are 2 strings, both of them are the target domain (example and com). If there are >=3 strings, get the last 3 strings. If the length of last string is 3, then the last 2 strings comprise the domain (example and com). If the length of last string is 2, then the last 3 strings comprise the domain (example and co and uk)
I think this should do the trick (I do hope this wasn't a homework :D )
//You may clean this method to make it more optimum / better
private String getRootDomain(String url){
String[] domainKeys = url.split("/")[2].split("\\.");
int length = domainKeys.length;
int dummy = domainKeys[0].equals("www")?1:0;
if(length-dummy == 2)
return domainKeys[length-2] + "." + domainKeys[length-1];
else{
if(domainKeys[length-1].length == 2) {
return domainKeys[length-3] + "." + domainKeys[length-2] + "." + domainKeys[length-1];
}
else{
return domainKeys[length-2] + "." + domainKeys[length-1];
}
}
}

Get domain name from given url

Given a URL, I want to extract domain name(It should not include 'www' part). Url can contain http/https. Here is the java code that I wrote. Though It seems to work fine, is there any better approach or are there some edge cases, that could fail.
public static String getDomainName(String url) throws MalformedURLException{
if(!url.startsWith("http") && !url.startsWith("https")){
url = "http://" + url;
}
URL netUrl = new URL(url);
String host = netUrl.getHost();
if(host.startsWith("www")){
host = host.substring("www".length()+1);
}
return host;
}
Input: http://google.com/blah
Output: google.com

If you want to parse a URL, use java.net.URI. java.net.URL has a bunch of problems -- its equals method does a DNS lookup which means code using it can be vulnerable to denial of service attacks when used with untrusted inputs.
"Mr. Gosling -- why did you make url equals suck?" explains one such problem. Just get in the habit of using java.net.URI instead.
public static String getDomainName(String url) throws URISyntaxException {
URI uri = new URI(url);
String domain = uri.getHost();
return domain.startsWith("www.") ? domain.substring(4) : domain;
}
should do what you want.
Though It seems to work fine, is there any better approach or are there some edge cases, that could fail.
Your code as written fails for the valid URLs:
httpfoo/bar -- relative URL with a path component that starts with http.
HTTP://example.com/ -- protocol is case-insensitive.
//example.com/ -- protocol relative URL with a host
www/foo -- a relative URL with a path component that starts with www
wwwexample.com -- domain name that does not starts with www. but starts with www.
Hierarchical URLs have a complex grammar. If you try to roll your own parser without carefully reading RFC 3986, you will probably get it wrong. Just use the one that's built into the core libraries.
If you really need to deal with messy inputs that java.net.URI rejects, see RFC 3986 Appendix B:
Appendix B. Parsing a URI Reference with a Regular Expression
As the "first-match-wins" algorithm is identical to the "greedy"
disambiguation method used by POSIX regular expressions, it is
natural and commonplace to use a regular expression for parsing the
potential five components of a URI reference.
The following line is the regular expression for breaking-down a
well-formed URI reference into its components.
^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
12 3 4 5 6 7 8 9
The numbers in the second line above are only to assist readability;
they indicate the reference points for each subexpression (i.e., each
paired parenthesis).

import java.net.*;
import java.io.*;
public class ParseURL {
public static void main(String[] args) throws Exception {
URL aURL = new URL("http://example.com:80/docs/books/tutorial"
+ "/index.html?name=networking#DOWNLOADING");
System.out.println("protocol = " + aURL.getProtocol()); //http
System.out.println("authority = " + aURL.getAuthority()); //example.com:80
System.out.println("host = " + aURL.getHost()); //example.com
System.out.println("port = " + aURL.getPort()); //80
System.out.println("path = " + aURL.getPath()); // /docs/books/tutorial/index.html
System.out.println("query = " + aURL.getQuery()); //name=networking
System.out.println("filename = " + aURL.getFile()); ///docs/books/tutorial/index.html?name=networking
System.out.println("ref = " + aURL.getRef()); //DOWNLOADING
}
}
Read more

Here is a short and simple line using InternetDomainName.topPrivateDomain() in Guava: InternetDomainName.from(new URL(url).getHost()).topPrivateDomain().toString()
Given http://www.google.com/blah, that will give you google.com. Or, given http://www.google.co.mx, it will give you google.co.mx.
As Sa Qada commented in another answer on this post, this question has been asked earlier: Extract main domain name from a given url. The best answer to that question is from Satya, who suggests Guava's InternetDomainName.topPrivateDomain()
public boolean isTopPrivateDomain()
Indicates whether this domain name is composed of exactly one
subdomain component followed by a public suffix. For example, returns
true for google.com and foo.co.uk, but not for www.google.com or
co.uk.
Warning: A true result from this method does not imply that the
domain is at the highest level which is addressable as a host, as many
public suffixes are also addressable hosts. For example, the domain
bar.uk.com has a public suffix of uk.com, so it would return true from
this method. But uk.com is itself an addressable host.
This method can be used to determine whether a domain is probably the
highest level for which cookies may be set, though even that depends
on individual browsers' implementations of cookie controls. See RFC
2109 for details.
Putting that together with URL.getHost(), which the original post already contains, gives you:
import com.google.common.net.InternetDomainName;
import java.net.URL;
public class DomainNameMain {
public static void main(final String... args) throws Exception {
final String urlString = "http://www.google.com/blah";
final URL url = new URL(urlString);
final String host = url.getHost();
final InternetDomainName name = InternetDomainName.from(host).topPrivateDomain();
System.out.println(urlString);
System.out.println(host);
System.out.println(name);
}
}

I wrote a method (see below) which extracts a url's domain name and which uses simple String matching. What it actually does is extract the bit between the first "://" (or index 0 if there's no "://" contained) and the first subsequent "/" (or index String.length() if there's no subsequent "/"). The remaining, preceding "www(_)*." bit is chopped off. I'm sure there'll be cases where this won't be good enough but it should be good enough in most cases!
Mike Samuel's post above says that the java.net.URI class could do this (and was preferred to the java.net.URL class) but I encountered problems with the URI class. Notably, URI.getHost() gives a null value if the url does not include the scheme, i.e. the "http(s)" bit.
/**
* Extracts the domain name from {#code url}
* by means of String manipulation
* rather than using the {#link URI} or {#link URL} class.
*
* #param url is non-null.
* #return the domain name within {#code url}.
*/
public String getUrlDomainName(String url) {
String domainName = new String(url);
int index = domainName.indexOf("://");
if (index != -1) {
// keep everything after the "://"
domainName = domainName.substring(index + 3);
}
index = domainName.indexOf('/');
if (index != -1) {
// keep everything before the '/'
domainName = domainName.substring(0, index);
}
// check for and remove a preceding 'www'
// followed by any sequence of characters (non-greedy)
// followed by a '.'
// from the beginning of the string
domainName = domainName.replaceFirst("^www.*?\\.", "");
return domainName;
}

I made a small treatment after the URI object creation
if (url.startsWith("http:/")) {
if (!url.contains("http://")) {
url = url.replaceAll("http:/", "http://");
}
} else {
url = "http://" + url;
}
URI uri = new URI(url);
String domain = uri.getHost();
return domain.startsWith("www.") ? domain.substring(4) : domain;

In my case i only needed the main domain and not the subdomain (no "www" or whatever the subdomain is) :
public static String getUrlDomain(String url) throws URISyntaxException {
URI uri = new URI(url);
String domain = uri.getHost();
String[] domainArray = domain.split("\\.");
if (domainArray.length == 1) {
return domainArray[0];
}
return domainArray[domainArray.length - 2] + "." + domainArray[domainArray.length - 1];
}
With this method the url "https://rest.webtoapp.io/llSlider?lg=en&t=8" will have for domain "webtoapp.io".

val host = url.split("/")[2]

All the above are good. This one seems really simple to me and easy to understand. Excuse the quotes. I wrote it for Groovy inside a class called DataCenter.
static String extractDomainName(String url) {
int start = url.indexOf('://')
if (start < 0) {
start = 0
} else {
start += 3
}
int end = url.indexOf('/', start)
if (end < 0) {
end = url.length()
}
String domainName = url.substring(start, end)
int port = domainName.indexOf(':')
if (port >= 0) {
domainName = domainName.substring(0, port)
}
domainName
}
And here are some junit4 tests:
#Test
void shouldFindDomainName() {
assert DataCenter.extractDomainName('http://example.com/path/') == 'example.com'
assert DataCenter.extractDomainName('http://subpart.example.com/path/') == 'subpart.example.com'
assert DataCenter.extractDomainName('http://example.com') == 'example.com'
assert DataCenter.extractDomainName('http://example.com:18445/path/') == 'example.com'
assert DataCenter.extractDomainName('example.com/path/') == 'example.com'
assert DataCenter.extractDomainName('example.com') == 'example.com'
}

try this one : java.net.URL;
JOptionPane.showMessageDialog(null, getDomainName(new URL("https://en.wikipedia.org/wiki/List_of_Internet_top-level_domains")));
public String getDomainName(URL url){
String strDomain;
String[] strhost = url.getHost().split(Pattern.quote("."));
String[] strTLD = {"com","org","net","int","edu","gov","mil","arpa"};
if(Arrays.asList(strTLD).indexOf(strhost[strhost.length-1])>=0)
strDomain = strhost[strhost.length-2]+"."+strhost[strhost.length-1];
else if(strhost.length>2)
strDomain = strhost[strhost.length-3]+"."+strhost[strhost.length-2]+"."+strhost[strhost.length-1];
else
strDomain = strhost[strhost.length-2]+"."+strhost[strhost.length-1];
return strDomain;}

There is a similar question Extract main domain name from a given url. If you take a look at this answer , you will see that it is very easy. You just need to use java.net.URL and String utility - Split

One of the way I did and worked for all of the cases is using Guava Library and regex in combination.
public static String getDomainNameWithGuava(String url) throws MalformedURLException,
URISyntaxException {
String host =new URL(url).getHost();
String domainName="";
try{
domainName = InternetDomainName.from(host).topPrivateDomain().toString();
}catch (IllegalStateException | IllegalArgumentException e){
domainName= getDomain(url,true);
}
return domainName;
}
getDomain() can be any common method with regex.

private static final String hostExtractorRegexString = "(?:https?://)?(?:www\\.)?(.+\\.)(com|au\\.uk|co\\.in|be|in|uk|org\\.in|org|net|edu|gov|mil)";
private static final Pattern hostExtractorRegexPattern = Pattern.compile(hostExtractorRegexString);
public static String getDomainName(String url){
if (url == null) return null;
url = url.trim();
Matcher m = hostExtractorRegexPattern.matcher(url);
if(m.find() && m.groupCount() == 2) {
return m.group(1) + m.group(2);
}
return null;
}
Explanation :
The regex has 4 groups. The first two are non-matching groups and the next two are matching groups.
The first non-matching group is "http" or "https" or ""
The second non-matching group is "www." or ""
The second matching group is the top level domain
The first matching group is anything after the non-matching groups and anything before the top level domain
The concatenation of the two matching groups will give us the domain/host name.
PS : Note that you can add any number of supported domains to the regex.

If the input url is user input. this method gives the most appropriate host name. if not found gives back the input url.
private String getHostName(String urlInput) {
urlInput = urlInput.toLowerCase();
String hostName=urlInput;
if(!urlInput.equals("")){
if(urlInput.startsWith("http") || urlInput.startsWith("https")){
try{
URL netUrl = new URL(urlInput);
String host= netUrl.getHost();
if(host.startsWith("www")){
hostName = host.substring("www".length()+1);
}else{
hostName=host;
}
}catch (MalformedURLException e){
hostName=urlInput;
}
}else if(urlInput.startsWith("www")){
hostName=urlInput.substring("www".length()+1);
}
return hostName;
}else{
return "";
}
}

To get the actual domain name, without the subdomain, I use:
private String getDomainName(String url) throws URISyntaxException {
String hostName = new URI(url).getHost();
if (!hostName.contains(".")) {
return hostName;
}
String[] host = hostName.split("\\.");
return host[host.length - 2];
}
Note that this won't work with second-level domains (like .co.uk).

// groovy
String hostname ={url -> url[(url.indexOf('://')+ 3)..-1]​.split('/')[0]​ }
hostname('http://hello.world.com/something') // return 'hello.world.com'
hostname('docker://quay.io/skopeo/stable') // return 'quay.io'

const val WWW = "www."
fun URL.domain(): String {
val domain: String = this.host
return if (domain.startsWith(ConstUtils.WWW)) {
domain.substring(ConstUtils.WWW.length)
} else {
domain
}
}

I use regex solution
public static String getDomainName(String url) {
return url.replaceAll("http(s)?://|www\\.|wap\\.|/.*", "");
}
It cleans url from "http/https/www./wap." and from all unnecessary things after / like "/questions" in "https://stackoverflow.com/questions" and we get just "stackoverflow.com"

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.