multipartstream.html

java 的上传功能很强大的实施上述事实上说是

<a name="503" href="#503">503</a>             <strong class="jxr_keyword">throws</strong> <a href="../../../../org/apache/commons/fileupload/MultipartStream.html">IllegalBoundaryException</a> {
<a name="504" href="#504">504</a>         <strong class="jxr_keyword">if</strong> (boundary.length != boundaryLength - BOUNDARY_PREFIX.length) {
<a name="505" href="#505">505</a>             <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> <a href="../../../../org/apache/commons/fileupload/MultipartStream.html">IllegalBoundaryException</a>(
<a name="506" href="#506">506</a>             <span class="jxr_string">"The length of a boundary token can not be changed"</span>);
<a name="507" href="#507">507</a>         }
<a name="508" href="#508">508</a>         System.arraycopy(boundary, 0, <strong class="jxr_keyword">this</strong>.boundary, BOUNDARY_PREFIX.length,
<a name="509" href="#509">509</a>                 boundary.length);
<a name="510" href="#510">510</a>     }
<a name="511" href="#511">511</a> 
<a name="512" href="#512">512</a> 
<a name="513" href="#513">513</a>     <em class="jxr_javadoccomment">/**</em>
<a name="514" href="#514">514</a> <em class="jxr_javadoccomment">     * &lt;p&gt;Reads the &lt;code&gt;header-part&lt;/code&gt; of the current</em>
<a name="515" href="#515">515</a> <em class="jxr_javadoccomment">     * &lt;code&gt;encapsulation&lt;/code&gt;.</em>
<a name="516" href="#516">516</a> <em class="jxr_javadoccomment">     *</em>
<a name="517" href="#517">517</a> <em class="jxr_javadoccomment">     * &lt;p&gt;Headers are returned verbatim to the input stream, including the</em>
<a name="518" href="#518">518</a> <em class="jxr_javadoccomment">     * trailing &lt;code&gt;CRLF&lt;/code&gt; marker. Parsing is left to the</em>
<a name="519" href="#519">519</a> <em class="jxr_javadoccomment">     * application.</em>
<a name="520" href="#520">520</a> <em class="jxr_javadoccomment">     *</em>
<a name="521" href="#521">521</a> <em class="jxr_javadoccomment">     * &lt;p&gt;&lt;strong&gt;TODO&lt;/strong&gt; allow limiting maximum header size to</em>
<a name="522" href="#522">522</a> <em class="jxr_javadoccomment">     * protect against abuse.</em>
<a name="523" href="#523">523</a> <em class="jxr_javadoccomment">     *</em>
<a name="524" href="#524">524</a> <em class="jxr_javadoccomment">     * @return The &lt;code&gt;header-part&lt;/code&gt; of the current encapsulation.</em>
<a name="525" href="#525">525</a> <em class="jxr_javadoccomment">     *</em>
<a name="526" href="#526">526</a> <em class="jxr_javadoccomment">     * @throws MalformedStreamException if the stream ends unexpecetedly.</em>
<a name="527" href="#527">527</a> <em class="jxr_javadoccomment">     */</em>
<a name="528" href="#528">528</a>     <strong class="jxr_keyword">public</strong> String readHeaders()
<a name="529" href="#529">529</a>     <strong class="jxr_keyword">throws</strong> <a href="../../../../org/apache/commons/fileupload/MultipartStream.html">MalformedStreamException</a> {
<a name="530" href="#530">530</a>         <strong class="jxr_keyword">int</strong> i = 0;
<a name="531" href="#531">531</a>         byte b;
<a name="532" href="#532">532</a>         <em class="jxr_comment">// to support multi-byte characters</em>
<a name="533" href="#533">533</a>         ByteArrayOutputStream baos = <strong class="jxr_keyword">new</strong> ByteArrayOutputStream();
<a name="534" href="#534">534</a>         <strong class="jxr_keyword">int</strong> size = 0;
<a name="535" href="#535">535</a>         <strong class="jxr_keyword">while</strong> (i &lt; HEADER_SEPARATOR.length) {
<a name="536" href="#536">536</a>             <strong class="jxr_keyword">try</strong> {
<a name="537" href="#537">537</a>                 b = readByte();
<a name="538" href="#538">538</a>             } <strong class="jxr_keyword">catch</strong> (IOException e) {
<a name="539" href="#539">539</a>                 <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> <a href="../../../../org/apache/commons/fileupload/MultipartStream.html">MalformedStreamException</a>(<span class="jxr_string">"Stream ended unexpectedly"</span>);
<a name="540" href="#540">540</a>             }
<a name="541" href="#541">541</a>             <strong class="jxr_keyword">if</strong> (++size &gt; HEADER_PART_SIZE_MAX) {
<a name="542" href="#542">542</a>                 <strong class="jxr_keyword">throw</strong> <strong class="jxr_keyword">new</strong> <a href="../../../../org/apache/commons/fileupload/MultipartStream.html">MalformedStreamException</a>(
<a name="543" href="#543">543</a>                         <span class="jxr_string">"Header section has more than "</span> + HEADER_PART_SIZE_MAX
<a name="544" href="#544">544</a>                         + <span class="jxr_string">" bytes (maybe it is not properly terminated)"</span>);
<a name="545" href="#545">545</a>             }
<a name="546" href="#546">546</a>             <strong class="jxr_keyword">if</strong> (b == HEADER_SEPARATOR[i]) {
<a name="547" href="#547">547</a>                 i++;
<a name="548" href="#548">548</a>             } <strong class="jxr_keyword">else</strong> {
<a name="549" href="#549">549</a>                 i = 0;
<a name="550" href="#550">550</a>             }
<a name="551" href="#551">551</a>             baos.write(b);
<a name="552" href="#552">552</a>         }
<a name="553" href="#553">553</a> 
<a name="554" href="#554">554</a>         String headers = <strong class="jxr_keyword">null</strong>;
<a name="555" href="#555">555</a>         <strong class="jxr_keyword">if</strong> (headerEncoding != <strong class="jxr_keyword">null</strong>) {
<a name="556" href="#556">556</a>             <strong class="jxr_keyword">try</strong> {
<a name="557" href="#557">557</a>                 headers = baos.toString(headerEncoding);
<a name="558" href="#558">558</a>             } <strong class="jxr_keyword">catch</strong> (UnsupportedEncodingException e) {
<a name="559" href="#559">559</a>                 <em class="jxr_comment">// Fall back to platform default if specified encoding is not</em>
<a name="560" href="#560">560</a>                 <em class="jxr_comment">// supported.</em>
<a name="561" href="#561">561</a>                 headers = baos.toString();
<a name="562" href="#562">562</a>             }
<a name="563" href="#563">563</a>         } <strong class="jxr_keyword">else</strong> {
<a name="564" href="#564">564</a>             headers = baos.toString();
<a name="565" href="#565">565</a>         }
<a name="566" href="#566">566</a> 
<a name="567" href="#567">567</a>         <strong class="jxr_keyword">return</strong> headers;
<a name="568" href="#568">568</a>     }
<a name="569" href="#569">569</a> 
<a name="570" href="#570">570</a> 
<a name="571" href="#571">571</a>     <em class="jxr_javadoccomment">/**</em>
<a name="572" href="#572">572</a> <em class="jxr_javadoccomment">     * &lt;p&gt;Reads &lt;code&gt;body-data&lt;/code&gt; from the current</em>
<a name="573" href="#573">573</a> <em class="jxr_javadoccomment">     * &lt;code&gt;encapsulation&lt;/code&gt; and writes its contents into the</em>
<a name="574" href="#574">574</a> <em class="jxr_javadoccomment">     * output &lt;code&gt;Stream&lt;/code&gt;.</em>
<a name="575" href="#575">575</a> <em class="jxr_javadoccomment">     *</em>
<a name="576" href="#576">576</a> <em class="jxr_javadoccomment">     * &lt;p&gt;Arbitrary large amounts of data can be processed by this</em>
<a name="577" href="#577">577</a> <em class="jxr_javadoccomment">     * method using a constant size buffer. (see {@link</em>
<a name="578" href="#578">578</a> <em class="jxr_javadoccomment">     * #MultipartStream(InputStream,byte[],int,</em>
<a name="579" href="#579">579</a> <em class="jxr_javadoccomment">     *   MultipartStream.ProgressNotifier) constructor}).</em>
<a name="580" href="#580">580</a> <em class="jxr_javadoccomment">     *</em>
<a name="581" href="#581">581</a> <em class="jxr_javadoccomment">     * @param output The &lt;code&gt;Stream&lt;/code&gt; to write data into. May</em>
<a name="582" href="#582">582</a> <em class="jxr_javadoccomment">     *               be null, in which case this method is equivalent</em>
<a name="583" href="#583">583</a> <em class="jxr_javadoccomment">     *               to {@link #discardBodyData()}.</em>
<a name="584" href="#584">584</a> <em class="jxr_javadoccomment">     *</em>
<a name="585" href="#585">585</a> <em class="jxr_javadoccomment">     * @return the amount of data written.</em>
<a name="586" href="#586">586</a> <em class="jxr_javadoccomment">     *</em>
<a name="587" href="#587">587</a> <em class="jxr_javadoccomment">     * @throws MalformedStreamException if the stream ends unexpectedly.</em>
<a name="588" href="#588">588</a> <em class="jxr_javadoccomment">     * @throws IOException              if an i/o error occurs.</em>
<a name="589" href="#589">589</a> <em class="jxr_javadoccomment">     */</em>
<a name="590" href="#590">590</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">int</strong> readBodyData(OutputStream output)
<a name="591" href="#591">591</a>             <strong class="jxr_keyword">throws</strong> MalformedStreamException, IOException {
<a name="592" href="#592">592</a>         <strong class="jxr_keyword">final</strong> InputStream istream = newInputStream();
<a name="593" href="#593">593</a>         <strong class="jxr_keyword">return</strong> (<strong class="jxr_keyword">int</strong>) Streams.copy(istream, output, false);
<a name="594" href="#594">594</a>     }
<a name="595" href="#595">595</a> 
<a name="596" href="#596">596</a>     <em class="jxr_javadoccomment">/**</em>
<a name="597" href="#597">597</a> <em class="jxr_javadoccomment">     * Creates a new {@link ItemInputStream}.</em>
<a name="598" href="#598">598</a> <em class="jxr_javadoccomment">     * @return A new instance of {@link ItemInputStream}.</em>
<a name="599" href="#599">599</a> <em class="jxr_javadoccomment">     */</em>
<a name="600" href="#600">600</a>     <a href="../../../../org/apache/commons/fileupload/MultipartStream.html">ItemInputStream</a> newInputStream() {
<a name="601" href="#601">601</a>         <strong class="jxr_keyword">return</strong> <strong class="jxr_keyword">new</strong> <a href="../../../../org/apache/commons/fileupload/MultipartStream.html">ItemInputStream</a>();
<a name="602" href="#602">602</a>     }
<a name="603" href="#603">603</a> 
<a name="604" href="#604">604</a>     <em class="jxr_javadoccomment">/**</em>
<a name="605" href="#605">605</a> <em class="jxr_javadoccomment">     * &lt;p&gt; Reads &lt;code&gt;body-data&lt;/code&gt; from the current</em>
<a name="606" href="#606">606</a> <em class="jxr_javadoccomment">     * &lt;code&gt;encapsulation&lt;/code&gt; and discards it.</em>
<a name="607" href="#607">607</a> <em class="jxr_javadoccomment">     *</em>
<a name="608" href="#608">608</a> <em class="jxr_javadoccomment">     * &lt;p&gt;Use this method to skip encapsulations you don't need or don't</em>
<a name="609" href="#609">609</a> <em class="jxr_javadoccomment">     * understand.</em>
<a name="610" href="#610">610</a> <em class="jxr_javadoccomment">     *</em>
<a name="611" href="#611">611</a> <em class="jxr_javadoccomment">     * @return The amount of data discarded.</em>
<a name="612" href="#612">612</a> <em class="jxr_javadoccomment">     *</em>
<a name="613" href="#613">613</a> <em class="jxr_javadoccomment">     * @throws MalformedStreamException if the stream ends unexpectedly.</em>
<a name="614" href="#614">614</a> <em class="jxr_javadoccomment">     * @throws IOException              if an i/o error occurs.</em>
<a name="615" href="#615">615</a> <em class="jxr_javadoccomment">     */</em>
<a name="616" href="#616">616</a>     <strong class="jxr_keyword">public</strong> <strong class="jxr_keyword">int</strong> discardBodyData()
<a name="617" href="#617">617</a>     <strong class="jxr_keyword">throws</strong> MalformedStreamException,
<a name="618" href="#618">618</a>     IOException {
<a name="619" href="#619">619</a>         <strong class="jxr_keyword">return</strong> readBodyData(<strong class="jxr_keyword">null</strong>);
<a name="620" href="#620">620</a>     }
<a name="621" href="#621">621</a> 
<a name="622" href="#622">622</a> 
<a name="623" href="#623">623</a>     <em class="jxr_javadoccomment">/**</em>
<a name="624" href="#624">624</a> <em class="jxr_javadoccomment">     * Finds the beginning of the first &lt;code&gt;encapsulation&lt;/code&gt;.</em>
<a name="625" href="#625">625</a> <em class="jxr_javadoccomment">     *</em>
<a name="626" href="#626">626</a> <em class="jxr_javadoccomment">     * @return &lt;code&gt;true&lt;/code&gt; if an &lt;code&gt;encapsulation&lt;/code&gt; was found in</em>
<a name="627" href="#627">627</a> <em class="jxr_javadoccomment">     *         the stream.</em>
<a name="628" href="#628">628</a> <em class="jxr_javadoccomment">     *</em>
<a name="629" href="#629">629</a> <em class="jxr_javadoccomment">     * @throws IOException if an i/o error occurs.</em>
<a name="630" href="#630">630</a> <em class="jxr_javadoccomm