hg/apifest08: task4/solution14/src/org/apidesign/apifest08/currency/Convertor.java@bf7622ec1713

     1 package org.apidesign.apifest08.currency;

     3 import java.util.ArrayList;

     4 import java.util.Collection;

     5 import java.util.Collections;

     6 import java.util.Date;

     7 import java.util.HashSet;

     8 import java.util.List;

     9 import java.util.Set;

    11 /** This is the skeleton class for your API. You need to make it public, so

    12  * it is accessible to your client code (currently in Task1Test.java) file.

    13  * <p>

    14  * Feel free to create additional classes or rename this one, just keep all

    15  * the API and its implementation in this package. Do not spread it outside

    16  * to other packages.

    17  */

    18 public final class Convertor {

    19     //version 1 fields

    21     private String currency1 = null;

    22     private String currency2 = null;

    23     private Rate rate = null;

    25     //version 2 field

    26     private List<TimeLimitedCurrencyRate> currencyRates = null;

    28     //version - for compatible mode

    29     private int instanceVersion = 0; //compatible mode because of problem with empty currency and CZE -> CZE (1:2) rate

    31     Convertor(String currency1, String currency2, Rate rate) {

    32         instanceVersion = 1;

    33         if ((currency1 == null) || (currency2 == null) || (rate == null)) {

    34             throw new IllegalArgumentException("All arguments have to be non-null.");

    35         }

    36         this.currency1 = currency1;

    37         this.currency2 = currency2;

    38         this.rate = rate;

    39     }

    41     Convertor(final CurrencyRate ... currencyRate) {

    42         instanceVersion = 2;

    44         if (currencyRate == null) {

    45             throw new IllegalArgumentException("Parameter cannot be null.");

    46         }

    47         if (currencyRate.length == 0) {

    48             throw new IllegalArgumentException("CurrencyRates cannot be empty.");

    49         }

    50         Set<Pair<String,String>> currencies = new HashSet<Pair<String,String>>();

    51         List<TimeLimitedCurrencyRate> curRates = new ArrayList<TimeLimitedCurrencyRate>();

    52         for (int i = 0; i < currencyRate.length; i++) {

    53             final CurrencyRate curRat = currencyRate[i];

    54             if (curRat == null) {

    55                 throw new IllegalArgumentException("Parameter cannot be null.");

    56             }

    57             //check that currencyRate is not defined twice

    58             Pair<String, String> curPair= new Pair<String, String>(curRat.getCurrency1(), curRat.getCurrency2());

    59             if (currencies.contains(curPair)) {

    60                 throw new IllegalArgumentException("Pair of currencies in a currency rate cannot be defined twice");

    61             }

    62             currencies.add(curPair);

    64             if (curRat instanceof TimeLimitedCurrencyRate) {

    65                 curRates.add((TimeLimitedCurrencyRate)curRat);

    66             } else {

    67                 curRates.add(new TimeLimitedCurrencyRate() { //create delegate which implements TimeLimitedCurrencyRate

    68                     public long getFromTime() {

    69                         return Long.MIN_VALUE;

    70                     }

    72                     public long getToTime() {

    73                         return Long.MAX_VALUE;

    74                     }

    76                     public String getCurrency1() {

    77                         return curRat.getCurrency1();

    78                     }

    80                     public String getCurrency2() {

    81                         return curRat.getCurrency2();

    82                     }

    84                     public Rate getRate() {

    85                         return curRat.getRate();

    86                     }

    87                 });

    88             }

    89         }

    90         this.currencyRates = Collections.unmodifiableList(curRates);

    91     }

    93     Convertor(final int fakeParameter, final TimeLimitedCurrencyRate ... currencyRate) { //use fake parameter just to specify which constructor should be invoked

    94         instanceVersion = 3;

    96         if (currencyRate == null) {

    97             throw new IllegalArgumentException("Parameter cannot be null.");

    98         }

    99         List<TimeLimitedCurrencyRate> curRates = new ArrayList<TimeLimitedCurrencyRate>();

   100         for (int i = 0; i < currencyRate.length; i++) {

   101             final TimeLimitedCurrencyRate curRat = currencyRate[i];

   102             if (curRat == null) {

   103                 throw new IllegalArgumentException("Parameter cannot be null.");

   104             }

   106             curRates.add(curRat);

   107         }

   108         this.currencyRates = Collections.unmodifiableList(curRates);

   109     }

   111     public double convert(String fromCurrency, String toCurrency, int amount) {

   112         return convert(fromCurrency, toCurrency, amount, System.currentTimeMillis());

   113     }

   115     public double convert(String fromCurrency, String toCurrency, int amount, Date date) {

   116         if (date == null) {

   117             throw new IllegalArgumentException("Date cannot be null");

   118         }

   119         return convert(fromCurrency, toCurrency, amount, date.getTime());

   120     }

   122     public double convert(String fromCurrency, String toCurrency, int amount, long time) {

   123         if (instanceVersion == 1) {

   124             if ((fromCurrency == null) || (toCurrency == null)) {

   125                 throw new IllegalArgumentException("All arguments have to be non-null.");

   126             }

   128             if (currency1.equals(fromCurrency) && currency2.equals(toCurrency)) {

   129                 return rate.convertAtoB(amount);

   130             } else if (currency2.equals(fromCurrency) && currency1.equals(toCurrency)) {

   131                 return rate.convertBtoA(amount);

   132             } else {

   133                 throw new IllegalArgumentException("Convertor " + this.toString() +

   134                         " cannot work with currencies " + fromCurrency + " and " + toCurrency + ".");

   135             }

   136         } else { //instanceVersion >= 2

   137             //find suitable convertor

   138            for (TimeLimitedCurrencyRate curRate : currencyRates) {

   139                 if ((curRate.getCurrency1().equals(fromCurrency))&&

   140                         (curRate.getCurrency2().equals(toCurrency))&&

   141                         (curRate.getFromTime() <= time) &&

   142                         (curRate.getToTime() >= time))

   143                 {

   144                     return curRate.getRate().convertAtoB(amount);

   145                 }

   146             }

   147             //suitable convertor not found, try to find inverse convertor

   148             for (TimeLimitedCurrencyRate curRate : currencyRates) {

   149                 if ((curRate.getCurrency2().equals(fromCurrency))&&

   150                         (curRate.getCurrency1().equals(toCurrency))&&

   151                         (curRate.getFromTime() <= time) &&

   152                         (curRate.getToTime() >= time))

   153                 {

   154                     return curRate.getRate().convertBtoA(amount);

   155                 }

   156             }

   157             //even inverse convertor not found

   158             throw new IllegalArgumentException("Cannot work with selected currencies.");

   159         }

   160     }

   162     public double convert(String fromCurrency, String toCurrency, double amount) {

   163         return convert(fromCurrency, toCurrency, amount, System.currentTimeMillis());

   164     }

   166     public double convert(String fromCurrency, String toCurrency, double amount, Date date) {

   167         if (date == null) {

   168             throw new IllegalArgumentException("Date cannot be null");

   169         }

   170         return convert(fromCurrency, toCurrency, amount, date.getTime());

   171     }

   173     public double convert(String fromCurrency, String toCurrency, double amount, long time) {

   174         if (instanceVersion == 1) {

   175             if ((fromCurrency == null) || (toCurrency == null)) {

   176                 throw new IllegalArgumentException("All arguments have to be non-null.");

   177             }

   179             if (currency1.equals(fromCurrency) && currency2.equals(toCurrency)) {

   180                 return rate.convertAtoB(amount);

   181             } else if (currency2.equals(fromCurrency) && currency1.equals(toCurrency)) {

   182                 return rate.convertBtoA(amount);

   183             } else {

   184                 throw new IllegalArgumentException("Convertor " + this.toString() +

   185                         " cannot work with currencies " + fromCurrency + " and " + toCurrency + ".");

   186             }

   187         } else { //instanceVersion >= 2

   188             //find suitable convertor

   189             for (TimeLimitedCurrencyRate curRate : currencyRates) {

   190                 if ((curRate.getCurrency1().equals(fromCurrency))&&

   191                         (curRate.getCurrency2().equals(toCurrency))&&

   192                         (curRate.getFromTime() <= time) &&

   193                         (curRate.getToTime() >= time))

   194                 {

   195                     return curRate.getRate().convertAtoB(amount);

   196                 }

   197             }

   198             //suitable convertor not found, try to find inverse convertor

   199             for (TimeLimitedCurrencyRate curRate : currencyRates) {

   200                 if ((curRate.getCurrency2().equals(fromCurrency))&&

   201                         (curRate.getCurrency1().equals(toCurrency))&&

   202                         (curRate.getFromTime() <= time) &&

   203                         (curRate.getToTime() >= time))

   204                 {

   205                     return curRate.getRate().convertBtoA(amount);

   206                 }

   207             }

   208             //even inverse convertor not found

   209             throw new IllegalArgumentException("Cannot work with selected currencies.");

   210         }

   211     }

   213     /**

   214      * Returns currency rates. If instantiated with constructor from vesion 1

   215      * it creates new collection with one CurrencyRate.

   216      * Note, it can cause exception because of empty currencies or same currencies.

   217      */

   218     public Collection<CurrencyRate> getCurrencyRates() {

   219         if (instanceVersion == 1) {

   220             List<CurrencyRate> ret = new ArrayList<CurrencyRate>();

   221             ret.add(new CurrencyRateImpl(currency1, currency2, rate)); //here it checks that currency rate is not nonsense

   222             return Collections.unmodifiableCollection(ret);

   223         } else { //instanceVersion >= 2

   224             List<CurrencyRate> ret = new ArrayList<CurrencyRate>(currencyRates);

   225             return Collections.unmodifiableCollection(ret);

   226         }

   227     }

   229     public Collection<TimeLimitedCurrencyRate> getTimeLimitedCurrencyRates() {

   230         if (instanceVersion == 1) {

   231             List<TimeLimitedCurrencyRate> ret = new ArrayList<TimeLimitedCurrencyRate>();

   232             ret.add(new CurrencyRateImpl(currency1, currency2, rate)); //here it checks that currency rate is not nonsense

   233             return Collections.unmodifiableCollection(ret);

   234         } else { //instanceVersion >= 2

   235             List<TimeLimitedCurrencyRate> ret = new ArrayList<TimeLimitedCurrencyRate>(currencyRates);

   236             return Collections.unmodifiableCollection(ret);

   237         }

   238     }

   240     @Override

   241     public String toString() {

   242         if (instanceVersion == 1) {

   243             return currency1 + currency2;

   244         } else { //instanceVersion == 2

   245             return super.toString(); //better be compatible in future :-)

   246         }

   247     }

   249     @Override

   250     public boolean equals(Object obj) {

   251         if (instanceVersion == 1) {

   252             if (obj == null) {

   253                 return false;

   254             }

   255             if (getClass() != obj.getClass()) {

   256                 return false;

   257             }

   258             final Convertor other = (Convertor) obj;

   259             if (this.currency1 != other.currency1 && (this.currency1 == null || !this.currency1.equals(other.currency1))) {

   260                 return false;

   261             }

   262             if (this.currency2 != other.currency2 && (this.currency2 == null || !this.currency2.equals(other.currency2))) {

   263                 return false;

   264             }

   265             if (this.rate != other.rate && (this.rate == null || !this.rate.equals(other.rate))) {

   266                 return false;

   267             }

   268             return true;

   269         } else { //instanceVersion == 2

   270             return super.equals(obj); //better be compatible in future :-)

   271         }

   272     }

   274     @Override

   275     public int hashCode() {

   276         if (instanceVersion == 1) {

   277             int hash = 5;

   278             hash = 67 * hash + (this.currency1 != null ? this.currency1.hashCode() : 0);

   279             hash = 67 * hash + (this.currency2 != null ? this.currency2.hashCode() : 0);

   280             hash = 67 * hash + (this.rate != null ? this.rate.hashCode() : 0);

   281         return hash;

   282         } else { //instanceVersion == 2

   283             return super.hashCode(); //better be compatible in future :-)

   284         }

   285     }

   286 }

author	Jaroslav Tulach <jaroslav.tulach@apidesign.org>
	Fri, 17 Oct 2008 17:35:52 +0200
changeset 67	bf7622ec1713
parent 61	58ec6da75f6f
permissions	-rw-r--r--