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src/java.base/share/classes/sun/nio/cs/StandardCharsets.java.template

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rev 17455 : 8184665: Skip name and alias checks for standard Charsets
Reviewed-by: sherman


  34 import java.util.Iterator;
  35 import java.util.Map;
  36 import sun.security.action.GetPropertyAction;
  37 
  38 public class StandardCharsets extends CharsetProvider {
  39 
  40     _INCLUDE_ALIASES_TABLES_
  41     _INCLUDE_ALIASES_MAP_
  42     _INCLUDE_CLASSES_MAP_
  43     _INCLUDE_CACHE_MAP_
  44 
  45     // Maps canonical names to class names
  46     private final Map<String,String> classMap;
  47     // Maps alias names to canonical names
  48     private final Map<String,String> aliasMap;
  49     // Maps canonical names to cached instances
  50     private final Map<String,Charset> cache;
  51 
  52     private static final String packagePrefix = "sun.nio.cs";
  53 






  54     public StandardCharsets() {
  55         this.aliasMap = new Aliases();
  56         this.classMap = new Classes();
  57         this.cache = new Cache();
  58     }
  59 
  60     private String canonicalize(String csn) {
  61         String acn = aliasMap.get(csn);
  62         return (acn != null) ? acn : csn;
  63     }
  64 
  65     // Private ASCII-only version, optimized for interpretation during startup
  66     //
  67     private static String toLower(String s) {
  68         int n = s.length();
  69         boolean allLower = true;
  70         for (int i = 0; i < n; i++) {
  71             int c = s.charAt(i);
  72             if (((c - 'A') | ('Z' - c)) >= 0) {
  73                 allLower = false;


  86         }
  87         return new String(ca);
  88     }
  89 
  90     private Charset lookup(String charsetName) {
  91         init();
  92         String csn = canonicalize(toLower(charsetName));
  93 
  94         // Check cache first
  95         Charset cs = cache.get(csn);
  96         if (cs != null)
  97             return cs;
  98 
  99         // Do we even support this charset?
 100         String cln = classMap.get(csn);
 101         if (cln == null)
 102             return null;
 103 
 104         // As all charset class names added to classMap are string literals we
 105         // can check identity here as an optimization
 106         if (cln == "US_ASCII") {
 107             return cache(csn, new US_ASCII());
 108         }
 109         if (cln == "ISO_8859_1") {
 110             return cache(csn, new ISO_8859_1());
 111         }
 112         if (cln == "UTF_8") {
 113             return cache(csn, new UTF_8());
 114         }
 115 
 116         // Instantiate the charset and cache it
 117         try {
 118             @SuppressWarnings("deprecation")
 119             Object o = Class.forName(packagePrefix + "." + cln,
 120                                      true,
 121                                      this.getClass().getClassLoader()).newInstance();
 122             return cache(csn, (Charset)o);
 123         } catch (ClassNotFoundException |
 124                  IllegalAccessException |
 125                  InstantiationException x) {
 126             return null;
 127         }
 128     }
 129 
 130     private Charset cache(String csn, Charset cs) {
 131         cache.put(csn, cs);
 132         return cs;




  34 import java.util.Iterator;
  35 import java.util.Map;
  36 import sun.security.action.GetPropertyAction;
  37 
  38 public class StandardCharsets extends CharsetProvider {
  39 
  40     _INCLUDE_ALIASES_TABLES_
  41     _INCLUDE_ALIASES_MAP_
  42     _INCLUDE_CLASSES_MAP_
  43     _INCLUDE_CACHE_MAP_
  44 
  45     // Maps canonical names to class names
  46     private final Map<String,String> classMap;
  47     // Maps alias names to canonical names
  48     private final Map<String,String> aliasMap;
  49     // Maps canonical names to cached instances
  50     private final Map<String,Charset> cache;
  51 
  52     private static final String packagePrefix = "sun.nio.cs";
  53 
  54     public static final String US_ASCII = "US-ASCII";
  55 
  56     public static final String ISO_8859_1 = "ISO-8859-1";
  57 
  58     public static final String UTF_8 = "UTF-8";
  59 
  60     public StandardCharsets() {
  61         this.aliasMap = new Aliases();
  62         this.classMap = new Classes();
  63         this.cache = new Cache();
  64     }
  65 
  66     private String canonicalize(String csn) {
  67         String acn = aliasMap.get(csn);
  68         return (acn != null) ? acn : csn;
  69     }
  70 
  71     // Private ASCII-only version, optimized for interpretation during startup
  72     //
  73     private static String toLower(String s) {
  74         int n = s.length();
  75         boolean allLower = true;
  76         for (int i = 0; i < n; i++) {
  77             int c = s.charAt(i);
  78             if (((c - 'A') | ('Z' - c)) >= 0) {
  79                 allLower = false;


  92         }
  93         return new String(ca);
  94     }
  95 
  96     private Charset lookup(String charsetName) {
  97         init();
  98         String csn = canonicalize(toLower(charsetName));
  99 
 100         // Check cache first
 101         Charset cs = cache.get(csn);
 102         if (cs != null)
 103             return cs;
 104 
 105         // Do we even support this charset?
 106         String cln = classMap.get(csn);
 107         if (cln == null)
 108             return null;
 109 
 110         // As all charset class names added to classMap are string literals we
 111         // can check identity here as an optimization
 112         if (cln == US_ASCII) {
 113             return cache(csn, new US_ASCII());
 114         }
 115         if (cln == ISO_8859_1) {
 116             return cache(csn, new ISO_8859_1());
 117         }
 118         if (cln == UTF_8) {
 119             return cache(csn, new UTF_8());
 120         }
 121 
 122         // Instantiate the charset and cache it
 123         try {
 124             @SuppressWarnings("deprecation")
 125             Object o = Class.forName(packagePrefix + "." + cln,
 126                                      true,
 127                                      this.getClass().getClassLoader()).newInstance();
 128             return cache(csn, (Charset)o);
 129         } catch (ClassNotFoundException |
 130                  IllegalAccessException |
 131                  InstantiationException x) {
 132             return null;
 133         }
 134     }
 135 
 136     private Charset cache(String csn, Charset cs) {
 137         cache.put(csn, cs);
 138         return cs;


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