Enhance type safety when getting tag values (#63)

This removes all uses of `ReadableHeader::getValue` which returns
`Object` and replaces them with methods that return specific types.
This simplifies the code and eliminates the need for the caller to
cast the result.

The method `RpmBaseTag::getDataType` was added to store the tag's
data type. The tag's data type is checked when the various
`ReadableHeader` methods are called.

Author: dwalluck

rpm/src/main/java/org/eclipse/packager/rpm/ReadableHeader.java

@@ -13,14 +13,22 @@
 
 package org.eclipse.packager.rpm;
 
-import java.util.Optional;
+import java.util.List;
 
 public interface ReadableHeader<T extends RpmBaseTag> {
-    /**
-     * Get the value from a header structure
-     *
-     * @param tag the tag
-     * @return the optional value
-     */
-    public Optional<Object> getValue(T tag);
+    boolean hasTag(T tag);
+
+    String getString(T tag);
+
+    Integer getInteger(T tag);
+
+    Long getLong(T tag);
+
+    List<String> getStringList(T tag);
+
+    List<Integer> getIntegerList(T tag);
+
+    List<Long> getLongList(T tag);
+
+    byte[] getByteArray(T tag);
 }

rpm/src/main/java/org/eclipse/packager/rpm/RpmBaseTag.java

@@ -23,5 +23,12 @@ public interface RpmBaseTag {
      *
      * @return the key value
      */
-    public Integer getValue();
+    Integer getValue();
+
+    /**
+     * Get the data type of the tag.
+     *
+     * @return the class representing the data type of this tag
+     */
+    Class<?> getDataType();
 }

rpm/src/main/java/org/eclipse/packager/rpm/RpmSignatureTag.java

@@ -17,31 +17,39 @@
 import java.util.Map;
 
 public enum RpmSignatureTag implements RpmBaseTag {
-    PUBKEYS(266),
-    DSAHEADER(267),
-    RSAHEADER(268),
-    SHA1HEADER(269),
-    LONGARCHIVESIZE(271),
-    SHA256HEADER(273),
-
-    SIZE(1000),
-    PGP(1002),
-    MD5(1004),
-    PAYLOAD_SIZE(1007),
-    LONGSIZE(5009);
+    PUBKEYS(266, String[].class),
+    DSAHEADER(267, byte[].class),
+    RSAHEADER(268, byte[].class),
+    SHA1HEADER(269, String.class),
+    LONGARCHIVESIZE(271, Long.class),
+    SHA256HEADER(273, String.class),
+
+    SIZE(1000, Integer.class),
+    PGP(1002, byte[].class),
+    MD5(1004, byte[].class),
+    PAYLOAD_SIZE(1007, Integer.class),
+    LONGSIZE(5009, Long.class);
 
     private final Integer value;
 
-    RpmSignatureTag(final Integer value) {
+    private final Class<?> dataType;
+
+    <T> RpmSignatureTag(final Integer value, final Class<T> dataType) {
         this.value = value;
+        this.dataType = dataType;
     }
 
     @Override
     public Integer getValue() {
         return this.value;
     }
 
-    private final static Map<Integer, RpmSignatureTag> all = new HashMap<>(RpmSignatureTag.values().length);
+    @Override
+    public Class<?> getDataType() {
+        return this.dataType;
+    }
+
+    private static final Map<Integer, RpmSignatureTag> all = new HashMap<>(RpmSignatureTag.values().length);
 
     static {
         for (final RpmSignatureTag tag : values()) {
@@ -52,4 +60,10 @@ public Integer getValue() {
     public static RpmSignatureTag find(final Integer value) {
         return all.get(value);
     }
+
+    @Override
+    public String toString() {
+        RpmSignatureTag tag = find(this.value);
+        return dataType.getSimpleName() + " " + (tag != null ? tag.name() + "(" + this.value + ")" : "UNKNOWN(" + this.value + ")");
+    }
 }

rpm/src/main/java/org/eclipse/packager/rpm/RpmTag.java

@@ -17,114 +17,121 @@
 import java.util.Map;
 
 public enum RpmTag implements RpmBaseTag {
-    NAME(1000),
-    VERSION(1001),
-    RELEASE(1002),
-    EPOCH(1003),
-    SUMMARY(1004),
-    DESCRIPTION(1005),
-    BUILDTIME(1006),
-    BUILDHOST(1007),
-    SIZE(1009),
-    DISTRIBUTION(1010),
-    VENDOR(1011),
-    LICENSE(1014),
-    PACKAGER(1015),
-    GROUP(1016),
-    URL(1020),
-    OS(1021),
-    ARCH(1022),
-    PREINSTALL_SCRIPT(1023),
-    POSTINSTALL_SCRIPT(1024),
-    PREREMOVE_SCRIPT(1025),
-    POSTREMOVE_SCRIPT(1026),
-    FILE_SIZES(1028),
-    FILE_MODES(1030),
-    FILE_RDEVS(1033),
-    FILE_MTIMES(1034),
-    FILE_DIGESTS(1035),
-    FILE_LINKTO(1036),
-    FILE_FLAGS(1037),
-    FILE_USERNAME(1039),
-    FILE_GROUPNAME(1040),
-    SOURCE_PACKAGE(1044),
-    FILE_VERIFYFLAGS(1045),
-    ARCHIVE_SIZE(1046),
-    PROVIDE_NAME(1047),
-    REQUIRE_FLAGS(1048),
-    REQUIRE_NAME(1049),
-    REQUIRE_VERSION(1050),
-    CONFLICT_FLAGS(1053),
-    CONFLICT_NAME(1054),
-    CONFLICT_VERSION(1055),
-    RPMVERSION(1064),
-    TRIGGER_SCRIPTS(1065),
-    TRIGGER_NAME(1066),
-    TRIGGER_VERSION(1067),
-    TRIGGER_FLAGS(1068),
-    TRIGGER_INDEX(1069),
-    VERIFY_SCRIPT(1079),
-    CHANGELOG_TIMESTAMP(1080),
-    CHANGELOG_AUTHOR(1081),
-    CHANGELOG_TEXT(1082),
-    PREINSTALL_SCRIPT_PROG(1085),
-    POSTINSTALL_SCRIPT_PROG(1086),
-    PREREMOVE_SCRIPT_PROG(1087),
-    POSTREMOVE_SCRIPT_PROG(1088),
-    VERIFY_SCRIPT_PROG(1091),
-    TRIGGERSCRIPT_PROG(1092),
-    OBSOLETE_NAME(1090),
-    FILE_DEVICES(1095),
-    FILE_INODES(1096),
-    FILE_LANGS(1097),
-    PREFIXES(1098),
-    PROVIDE_FLAGS(1112),
-    PROVIDE_VERSION(1113),
-    OBSOLETE_FLAGS(1114),
-    OBSOLETE_VERSION(1115),
-    DIR_INDEXES(1116),
-    BASENAMES(1117),
-    DIRNAMES(1118),
-    OPTFLAGS(1122),
-    PAYLOAD_FORMAT(1124),
-    PAYLOAD_CODING(1125),
-    PAYLOAD_FLAGS(1126),
-    PLATFORM(1132),
-    PRETRANSACTION_SCRIPT(1151),
-    POSTTRANSACTION_SCRIPT(1152),
-    PRETRANSACTION_SCRIPT_PROG(1153),
-    POSTTRANSACTION_SCRIPT_PROG(1154),
-    LONGSIZE(5009),
-    FILE_DIGESTALGO(5011),
-    RECOMMEND_NAME(5046),
-    RECOMMEND_VERSION(5047),
-    RECOMMEND_FLAGS(5048),
-    SUGGEST_NAME(5049),
-    SUGGEST_VERSION(5050),
-    SUGGEST_FLAGS(5051),
-    SUPPLEMENT_NAME(5052),
-    SUPPLEMENT_VERSION(5053),
-    SUPPLEMENT_FLAGS(5054),
-    ENHANCE_NAME(5055),
-    ENHANCE_VERSION(5056),
-    ENHANCE_FLAGS(5057),
+    NAME(1000, String.class),
+    VERSION(1001, String.class),
+    RELEASE(1002, String.class),
+    EPOCH(1003, Integer.class),
+    SUMMARY(1004, String[].class),
+    DESCRIPTION(1005, String[].class),
+    BUILDTIME(1006, Integer.class),
+    BUILDHOST(1007, String.class),
+    SIZE(1009, Integer.class),
+    DISTRIBUTION(1010, String.class),
+    VENDOR(1011, String.class),
+    LICENSE(1014, String.class),
+    PACKAGER(1015, String.class),
+    GROUP(1016, String[].class),
+    URL(1020, String.class),
+    OS(1021, String.class),
+    ARCH(1022, String.class),
+    PREINSTALL_SCRIPT(1023, String.class),
+    POSTINSTALL_SCRIPT(1024, String.class),
+    PREREMOVE_SCRIPT(1025, String.class),
+    POSTREMOVE_SCRIPT(1026, String.class),
+    FILE_SIZES(1028, Integer[].class),
+    FILE_MODES(1030, Short[].class),
+    FILE_RDEVS(1033, Short[].class),
+    FILE_MTIMES(1034, Integer[].class),
+    FILE_DIGESTS(1035, String[].class),
+    FILE_LINKTO(1036, String[].class),
+    FILE_FLAGS(1037, Integer[].class),
+    FILE_USERNAME(1039, String[].class),
+    FILE_GROUPNAME(1040, String[].class),
+    SOURCE_PACKAGE(1044, String.class),
+    FILE_VERIFYFLAGS(1045, Integer[].class),
+    ARCHIVE_SIZE(1046, Integer.class),
+    PROVIDE_NAME(1047, String[].class),
+    REQUIRE_FLAGS(1048, Integer[].class),
+    REQUIRE_NAME(1049, String[].class),
+    REQUIRE_VERSION(1050, String[].class),
+    CONFLICT_FLAGS(1053, Integer[].class),
+    CONFLICT_NAME(1054, String[].class),
+    CONFLICT_VERSION(1055, String[].class),
+    RPMVERSION(1064, String.class),
+    TRIGGER_SCRIPTS(1065, String[].class),
+    TRIGGER_NAME(1066, String[].class),
+    TRIGGER_VERSION(1067, String[].class),
+    TRIGGER_FLAGS(1068, Integer[].class),
+    TRIGGER_INDEX(1069, Integer[].class),
+    VERIFY_SCRIPT(1079, String.class),
+    CHANGELOG_TIMESTAMP(1080, Integer[].class),
+    CHANGELOG_AUTHOR(1081, String[].class),
+    CHANGELOG_TEXT(1082, String[].class),
+    PREINSTALL_SCRIPT_PROG(1085, String[].class),
+    POSTINSTALL_SCRIPT_PROG(1086, String[].class),
+    PREREMOVE_SCRIPT_PROG(1087, String[].class),
+    POSTREMOVE_SCRIPT_PROG(1088, String[].class),
+    OBSOLETE_NAME(1090, String[].class),
+    VERIFY_SCRIPT_PROG(1091, String[].class),
+    TRIGGERSCRIPT_PROG(1092, String[].class),
+    FILE_DEVICES(1095, Integer[].class),
+    FILE_INODES(1096, Integer[].class),
+    FILE_LANGS(1097, String[].class),
+    PREFIXES(1098, String[].class),
+    PROVIDE_FLAGS(1112, Integer[].class),
+    PROVIDE_VERSION(1113, String[].class),
+    OBSOLETE_FLAGS(1114, Integer[].class),
+    OBSOLETE_VERSION(1115, String[].class),
+    DIR_INDEXES(1116, Integer.class),
+    BASENAMES(1117, String[].class),
+    DIRNAMES(1118, String[].class),
+    OPTFLAGS(1122, String.class),
+    PAYLOAD_FORMAT(1124, String.class),
+    PAYLOAD_CODING(1125, String.class),
+    PAYLOAD_FLAGS(1126, String.class),
+    PLATFORM(1132, String.class),
+    PRETRANSACTION_SCRIPT(1151, String.class),
+    POSTTRANSACTION_SCRIPT(1152, String.class),
+    PRETRANSACTION_SCRIPT_PROG(1153, String[].class),
+    POSTTRANSACTION_SCRIPT_PROG(1154, String[].class),
+    LONGSIZE(5009, Long.class),
+    FILE_DIGESTALGO(5011, Integer.class),
+    RECOMMEND_NAME(5046, String[].class),
+    RECOMMEND_VERSION(5047, String[].class),
+    RECOMMEND_FLAGS(5048, Integer[].class),
+    SUGGEST_NAME(5049, String[].class),
+    SUGGEST_VERSION(5050, String[].class),
+    SUGGEST_FLAGS(5051, Integer[].class),
+    SUPPLEMENT_NAME(5052, String[].class),
+    SUPPLEMENT_VERSION(5053, String[].class),
+    SUPPLEMENT_FLAGS(5054, Integer[].class),
+    ENHANCE_NAME(5055, String[].class),
+    ENHANCE_VERSION(5056, String[].class),
+    ENHANCE_FLAGS(5057, Integer[].class),
 
-    PAYLOAD_DIGEST(5092),
-    PAYLOAD_DIGEST_ALGO(5093),
-    PAYLOAD_DIGEST_ALT(5097);
+    PAYLOAD_DIGEST(5092, String[].class),
+    PAYLOAD_DIGEST_ALGO(5093, Integer.class),
+    PAYLOAD_DIGEST_ALT(5097, String[].class);
 
     private final Integer value;
 
-    RpmTag(final Integer value) {
+    private final Class<?> dataType;
+
+    <T> RpmTag(final Integer value, Class<T> dataType) {
         this.value = value;
+        this.dataType = dataType;
     }
 
     @Override
     public Integer getValue() {
         return this.value;
     }
 
-    private final static Map<Integer, RpmTag> all = new HashMap<>(RpmTag.values().length);
+    public Class<?> getDataType() {
+        return this.dataType;
+    }
+
+    private static final Map<Integer, RpmTag> all = new HashMap<>(RpmTag.values().length);
 
     static {
         for (final RpmTag tag : values()) {
@@ -135,4 +142,10 @@ public Integer getValue() {
     public static RpmTag find(final Integer value) {
         return all.get(value);
     }
+
+    @Override
+    public String toString() {
+        RpmTag tag = find(this.value);
+        return dataType.getSimpleName() + " " + (tag != null ? tag.name() + "(" + this.value + ")" : "UNKNOWN(" + this.value + ")");
+    }
 }