001package votorola.g.net; // Copyright 2011, Michael Allan. Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Votorola Software"), to deal in the Votorola Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicence, and/or sell copies of the Votorola Software, and to permit persons to whom the Votorola Software is furnished to do so, subject to the following conditions: The preceding copyright notice and this permission notice shall be included in all copies or substantial portions of the Votorola Software. THE VOTOROLA SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE VOTOROLA SOFTWARE OR THE USE OR OTHER DEALINGS IN THE VOTOROLA SOFTWARE. 002 003import java.io.*; 004import java.net.*; 005import votorola.g.lang.*; 006 007 008/** A writer that outputs strings encoded in MIME format 009 * application/x-www-form-urlencoded. It does only rudimentary buffering. Feeding it 010 * truly massive strings will stretch the buffer to an inefficient size [FIX with 011 * trimToSize]. 012 * 013 * @see URLEncoder 014 */ 015public @ThreadSafe final class URLEncodedWriter extends Writer 016{ 017 018 019 /** Constructs a URLEncodedWriter. 020 * 021 * @see #encoding() 022 * @param _out the underlying writer. 023 */ 024 public URLEncodedWriter( String _encoding, Writer _out ) 025 { 026 if( _out == null ) throw new NullPointerException(); // fail fast 027 028 encoding = _encoding; 029 out = _out; 030 } 031 032 033 034 // ------------------------------------------------------------------------------------ 035 036 037 /** The assumed character encoding, as required by URLEncoder. 038 * 039 * @see URLEncoder 040 */ 041 public String encoding() { return encoding; } 042 043 044 private final String encoding; 045 046 047 048 // - A p p e n d a b l e -------------------------------------------------------------- 049 050 051 public @Override URLEncodedWriter append( char c ) throws IOException 052 { 053 write( c ); 054 return URLEncodedWriter.this; 055 } 056 057 058 059 public @Override URLEncodedWriter append( CharSequence csq ) throws IOException 060 { 061 synchronized( lock ) 062 { 063 b.append( csq ); 064 bCheck(); 065 } 066 return URLEncodedWriter.this; 067 } 068 069 070 071 public @Override URLEncodedWriter append( CharSequence csq, int start, int end ) 072 throws IOException 073 { 074 synchronized( lock ) 075 { 076 b.append( csq, start, end ); 077 bCheck(); 078 } 079 return URLEncodedWriter.this; 080 } 081 082 083 // - C l o s e a b l e ---------------------------------------------------------------- 084 085 086 public void close() throws IOException 087 { 088 synchronized( lock ) 089 { 090 if( !isClosed ) flush(); 091 092 isClosed = true; 093 } 094 out.close(); 095 } 096 097 098 private @ThreadRestricted("holds lock") boolean isClosed; 099 100 101 102 // - F l u s h a b l e ---------------------------------------------------------------- 103 104 105 public void flush() throws IOException 106 { 107 synchronized( lock ) 108 { 109 openCheck(); 110 bFlush(); 111 } 112 out.flush(); 113 } 114 115 116 117 // - W r i t e r ---------------------------------------------------------------------- 118 119 120 public @Override void write( char[] cbuf ) throws IOException 121 { 122 synchronized( lock ) 123 { 124 b.append( cbuf ); 125 bCheck(); 126 } 127 } 128 129 130 131 public void write( char[] cbuf, int off, int len ) throws IOException 132 { 133 synchronized( lock ) 134 { 135 b.append( cbuf, off, len ); 136 bCheck(); 137 } 138 } 139 140 141 142 public @Override void write( int c ) throws IOException 143 { 144 synchronized( lock ) 145 { 146 b.append( (char)c ); 147 bCheck(); 148 } 149 } 150 151 152 153 public @Override void write( String str ) throws IOException { append( str ); } 154 155 156 157 public @Override void write( String str, int off, int len ) throws IOException 158 { 159 append( str, off, off + len ); 160 } 161 162 163 164//// P r i v a t e /////////////////////////////////////////////////////////////////////// 165 166 167 @ThreadRestricted("holds lock") 168 private final StringBuilder b = new StringBuilder( /*initial capacity*/FLUSH_THRESHOLD + 150 ); 169 170 171 172 private @ThreadRestricted("holds lock") void bCheck() throws IOException 173 { 174 assert Thread.holdsLock( lock ); 175 openCheck(); 176 if( b.length() > FLUSH_THRESHOLD ) bFlush(); 177 } 178 179 180 181 private @ThreadRestricted("holds lock") void bFlush() throws IOException 182 { 183 assert Thread.holdsLock( lock ); 184 out.write( URLEncoder.encode( b.toString(), encoding )); 185 b.delete( 0, b.length() ); 186 } 187 188 189 190 private static final int FLUSH_THRESHOLD = 350; 191 192 193 194 @ThreadRestricted("holds lock") 195 private void openCheck() throws IOException // uphold the contract of Writer 196 { 197 assert Thread.holdsLock( lock ); 198 if( isClosed ) throw new IOException( "attempt to operate on a closed writer" ); 199 } 200 201 202 203 private final Writer out; 204 205 206 207}