Servlet-Reader、InputStream

 1 /**
 2  * Retrieves the body of the request as binary data using
 3  * a {@link ServletInputStream}.  Either this method or 
 4  * {@link #getReader} may be called to read the body, not both.
 5  *
 6  * @return a {@link ServletInputStream} object containing
 7  * the body of the request
 8  *
 9  * @exception IllegalStateException if the {@link #getReader} method
10  * has already been called for this request
11  *
12  * @exception IOException if an input or output exception occurred
13  */
14 public ServletInputStream getInputStream() throws IOException; 

 1 /**
 2  * Retrieves the body of the request as character data using
 3  * a <code>BufferedReader</code>.  The reader translates the character
 4  * data according to the character encoding used on the body.
 5  * Either this method or {@link #getInputStream} may be called to read the
 6  * body, not both.
 7  * 
 8  * @return a <code>BufferedReader</code> containing the body of the request 
 9  *
10  * @exception UnsupportedEncodingException  if the character set encoding
11  * used is not supported and the text cannot be decoded
12  *
13  * @exception IllegalStateException if {@link #getInputStream} method
14  * has been called on this request
15  *
16  * @exception IOException if an input or output exception occurred
17  *
18  * @see #getInputStream
19  */
20 public BufferedReader getReader() throws IOException;

 1     /**
 2      * Returns the value of a request parameter as a <code>String</code>,
 3      * or <code>null</code> if the parameter does not exist. Request parameters
 4      * are extra information sent with the request.  For HTTP servlets,
 5      * parameters are contained in the query string or posted form data.
 6      *
 7      * <p>You should only use this method when you are sure the
 8      * parameter has only one value. If the parameter might have
 9      * more than one value, use {@link #getParameterValues}.
10      *
11      * <p>If you use this method with a multivalued
12      * parameter, the value returned is equal to the first value
13      * in the array returned by <code>getParameterValues</code>.
14      *
15      * <p>If the parameter data was sent in the request body, such as occurs
16      * with an HTTP POST request, then reading the body directly via {@link
17      * #getInputStream} or {@link #getReader} can interfere
18      * with the execution of this method.
19      *
20      * @param name a <code>String</code> specifying the name of the parameter
21      *
22      * @return a <code>String</code> representing the single value of
23      * the parameter
24      *
25      * @see #getParameterValues
26      */
27     public String getParameter(String name);

 1 public ServletInputStream getInputStream() throws IOException {
 2     //getReader类似
 3   if (usingReader) {
 4     throw new IllegalStateException
 5         (sm.getString("coyoteRequest.getInputStream.ise"));
 6   }
 7     //getReader类似
 8   usingInputStream = true;
 9   if (inputStream == null) {
10       //getReader是new CoyoteReader(inputBuffer)
11       //getParameter时调用的是getStream，只是比getInputStream少了using的相关处理，
12       //同样是inputStream = new CoyoteInputStream(inputBuffer)
13     inputStream = new CoyoteInputStream(inputBuffer);
14   }
15   return inputStream;
16 }

 1 //如果调用过getInputStream或getReader，则不对再body处理。
 2 //之前已经对url上的查询参数做了处理，getParameter可以无障碍访问url上的查询参数，
 3 //之后的逻辑仅针对body
 4 if (usingInputStream || usingReader) {
 5   success = true;
 6   return;
 7 }
 8 
 9 if( !getConnector().isParseBodyMethod(getMethod()) ) {
10   success = true;
11   return;
12 }
13 
14 String contentType = getContentType();
15 if (contentType == null) {
16   contentType = "";
17 }
18 int semicolon = contentType.indexOf(‘;‘);
19 if (semicolon >= 0) {
20   contentType = contentType.substring(0, semicolon).trim();
21 } else {
22   contentType = contentType.trim();
23 }
24 //getParameter方法会处理multipart/form-data、application/x-www-form-urlencoded两种Content-Type（都是form），
25 //但getParameter只能获取到application/x-www-form-urlencoded的数据
26 if ("multipart/form-data".equals(contentType)) {
27     //多部会被放到parts容器中
28   parseParts(false);
29   success = true;
30   return;
31 }
32 if (!("application/x-www-form-urlencoded".equals(contentType))) {
33   success = true;
34   return;
35 }
36 //对application/x-www-form-urlencoded数据进一步处理，数据会存放在parameterMap中