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25 
26 package java.util.zip;
27 
28 import java.nio.ByteBuffer;
29 import java.nio.CharBuffer;
30 import java.nio.charset.Charset;
31 import java.nio.charset.StandardCharsets;
32 import java.nio.charset.CharsetDecoder;
33 import java.nio.charset.CharsetEncoder;
34 import java.nio.charset.CoderResult;
35 import java.nio.charset.CodingErrorAction;
36 import java.util.Arrays;
37 import sun.nio.cs.ArrayDecoder;
38 import sun.nio.cs.ArrayEncoder;
39 
40 /**
41  * Utility class for zipfile name and comment decoding and encoding
42  */
43 
44 final class ZipCoder {
45 
toString(byte[] ba, int length)46     String toString(byte[] ba, int length) {
47         CharsetDecoder cd = decoder().reset();
48         int len = (int)(length * cd.maxCharsPerByte());
49         char[] ca = new char[len];
50         if (len == 0)
51             return new String(ca);
52         // UTF-8 only for now. Other ArrayDeocder only handles
53         // CodingErrorAction.REPLACE mode. ZipCoder uses
54         // REPORT mode.
55         if (isUTF8 && cd instanceof ArrayDecoder) {
56             int clen = ((ArrayDecoder)cd).decode(ba, 0, length, ca);
57             if (clen == -1)    // malformed
58                 throw new IllegalArgumentException("MALFORMED");
59             return new String(ca, 0, clen);
60         }
61         ByteBuffer bb = ByteBuffer.wrap(ba, 0, length);
62         CharBuffer cb = CharBuffer.wrap(ca);
63         CoderResult cr = cd.decode(bb, cb, true);
64         if (!cr.isUnderflow())
65             throw new IllegalArgumentException(cr.toString());
66         cr = cd.flush(cb);
67         if (!cr.isUnderflow())
68             throw new IllegalArgumentException(cr.toString());
69         return new String(ca, 0, cb.position());
70     }
71 
toString(byte[] ba)72     String toString(byte[] ba) {
73         return toString(ba, ba.length);
74     }
75 
getBytes(String s)76     byte[] getBytes(String s) {
77         CharsetEncoder ce = encoder().reset();
78         char[] ca = s.toCharArray();
79         int len = (int)(ca.length * ce.maxBytesPerChar());
80         byte[] ba = new byte[len];
81         if (len == 0)
82             return ba;
83         // UTF-8 only for now. Other ArrayDeocder only handles
84         // CodingErrorAction.REPLACE mode.
85         if (isUTF8 && ce instanceof ArrayEncoder) {
86             int blen = ((ArrayEncoder)ce).encode(ca, 0, ca.length, ba);
87             if (blen == -1)    // malformed
88                 throw new IllegalArgumentException("MALFORMED");
89             return Arrays.copyOf(ba, blen);
90         }
91         ByteBuffer bb = ByteBuffer.wrap(ba);
92         CharBuffer cb = CharBuffer.wrap(ca);
93         CoderResult cr = ce.encode(cb, bb, true);
94         if (!cr.isUnderflow())
95             throw new IllegalArgumentException(cr.toString());
96         cr = ce.flush(bb);
97         if (!cr.isUnderflow())
98             throw new IllegalArgumentException(cr.toString());
99         if (bb.position() == ba.length)  // defensive copy?
100             return ba;
101         else
102             return Arrays.copyOf(ba, bb.position());
103     }
104 
105     // assume invoked only if "this" is not utf8
getBytesUTF8(String s)106     byte[] getBytesUTF8(String s) {
107         if (isUTF8)
108             return getBytes(s);
109         if (utf8 == null)
110             utf8 = new ZipCoder(StandardCharsets.UTF_8);
111         return utf8.getBytes(s);
112     }
113 
114 
toStringUTF8(byte[] ba, int len)115     String toStringUTF8(byte[] ba, int len) {
116         if (isUTF8)
117             return toString(ba, len);
118         if (utf8 == null)
119             utf8 = new ZipCoder(StandardCharsets.UTF_8);
120         return utf8.toString(ba, len);
121     }
122 
isUTF8()123     boolean isUTF8() {
124         return isUTF8;
125     }
126 
127     private Charset cs;
128     private CharsetDecoder dec;
129     private CharsetEncoder enc;
130     private boolean isUTF8;
131     private ZipCoder utf8;
132 
ZipCoder(Charset cs)133     private ZipCoder(Charset cs) {
134         this.cs = cs;
135         this.isUTF8 = cs.name().equals(StandardCharsets.UTF_8.name());
136     }
137 
get(Charset charset)138     static ZipCoder get(Charset charset) {
139         return new ZipCoder(charset);
140     }
141 
decoder()142     private CharsetDecoder decoder() {
143         if (dec == null) {
144             dec = cs.newDecoder()
145               .onMalformedInput(CodingErrorAction.REPORT)
146               .onUnmappableCharacter(CodingErrorAction.REPORT);
147         }
148         return dec;
149     }
150 
encoder()151     private CharsetEncoder encoder() {
152         if (enc == null) {
153             enc = cs.newEncoder()
154               .onMalformedInput(CodingErrorAction.REPORT)
155               .onUnmappableCharacter(CodingErrorAction.REPORT);
156         }
157         return enc;
158     }
159 }
160