buildSrc/src/main/java/cc/squirreljme/plugin/util/SimpleHTTPResponseBuilder.java

   1 // -*- Mode: Java; indent-tabs-mode: t; tab-width: 4 -*-
   2 // ---------------------------------------------------------------------------
   3 // SquirrelJME
   4 //     Copyright (C) Stephanie Gawroriski <xer@multiphasicapps.net>
   5 // ---------------------------------------------------------------------------
   6 // SquirrelJME is under the GNU General Public License v3+, or later.
   7 // See license.mkd for licensing and copyright information.
   8 // ---------------------------------------------------------------------------
   9
  10 package cc.squirreljme.plugin.util;
  11
  12 import java.io.ByteArrayOutputStream;
  13 import java.io.IOException;
  14 import java.io.InputStream;
  15 import java.util.Map;
  16 import java.util.TreeMap;
  17
  18 /**
  19  * Builder for HTTP responses.
  20  *
  21  * @since 2020/06/26
  22  */
  23 public final class SimpleHTTPResponseBuilder
  24 {
  25         /** Headers. */
  26         private final Map<String, String> _headers =
  27                 new TreeMap<>(String.CASE_INSENSITIVE_ORDER);
  28
  29         /** The status. */
  30         public SimpleHTTPStatus status;
  31
  32         /** The body. */
  33         private byte[] _body;
  34
  35         /**
  36          * Sets the header key and value.
  37          *
  38          * @param __key The key.
  39          * @param __value The value.
  40          * @since 2020/06/26
  41          */
  42         public void addHeader(String __key, String __value)
  43         {
  44                 this._headers.put(__key, __value);
  45         }
  46
  47         /**
  48          * Sets the response body.
  49          *
  50          * @param __bytes The bytes to use.
  51          * @throws NullPointerException On null arguments.
  52          * @since 2020/06/26
  53          */
  54         public void body(byte... __bytes)
  55                 throws NullPointerException
  56         {
  57                 if (__bytes == null)
  58                         throw new NullPointerException("NARG");
  59
  60                 this._body = __bytes.clone();
  61
  62                 // Ensure that the content length is updated
  63                 this.addHeader("Content-Length",
  64                         Integer.toString(__bytes.length));
  65         }
  66
  67         /**
  68          * Builds the request.
  69          *
  70          * @return The request.
  71          * @since 2020/06/26
  72          */
  73         public SimpleHTTPResponse build()
  74         {
  75                 return new SimpleHTTPResponse(this.status, this._headers, this._body);
  76         }
  77
  78         /**
  79          * Splices resources into the body.
  80          *
  81          * @param __basis The base class, may be {@code null} if not used.
  82          * @param __header The header.
  83          * @param __footer The footer.
  84          * @param __center The center body data.
  85          * @throws NullPointerException If the header/footer were specified and the
  86          * basis is {@code null}.
  87          * @since 2020/06/27
  88          */
  89         public void spliceResources(Class<?> __basis, String __header,
  90                 String __footer, byte... __center)
  91                 throws NullPointerException
  92         {
  93                 if (__basis == null && (__header != null || __footer != null))
  94                         throw new NullPointerException("NARG");
  95
  96                 // Write the response body
  97                 try (ByteArrayOutputStream baos = new ByteArrayOutputStream())
  98                 {
  99                         // Implant the header
 100                         byte[] buf = new byte[4096];
 101                         if (__header != null)
 102                                 try (InputStream in = __basis.getResourceAsStream(__header))
 103                                 {
 104                                         for (;;)
 105                                         {
 106                                                 int rc = in.read(buf);
 107
 108                                                 if (rc < 0)
 109                                                         break;
 110
 111                                                 baos.write(buf, 0, rc);
 112                                         }
 113                                 }
 114
 115                         // Write the center content here
 116                         if (__center != null)
 117                                 baos.write(__center);
 118
 119                         // Implant the footer
 120                         if (__footer != null)
 121                                 try (InputStream in = __basis.getResourceAsStream(__footer))
 122                                 {
 123                                         for (;;)
 124                                         {
 125                                                 int rc = in.read(buf);
 126
 127                                                 if (rc < 0)
 128                                                         break;
 129
 130                                                 baos.write(buf, 0, rc);
 131                                         }
 132                                 }
 133
 134                         // Send the client the body
 135                         this.body(baos.toByteArray());
 136                 }
 137
 138                 // Failed to write the body
 139                 catch (IOException|NullPointerException e)
 140                 {
 141                         throw new RuntimeException("Could not write response body.", e);
 142                 }
 143         }
 144
 145         /**
 146          * Sets the status.
 147          *
 148          * @param __status The status to use.
 149          * @return {@code this}.
 150          * @since 2020/06/26
 151          */
 152         public SimpleHTTPResponseBuilder status(SimpleHTTPStatus __status)
 153         {
 154                 this.status = __status;
 155
 156                 return this;
 157         }
 158 }