java - 使用 Swizzle Stream 替换流中的字符串

Question

我已经尝试使用 Swizzle Stream 库来替换输入流中的标记。

  String RESOURCE_PATH = "FakePom.xml";
  InputStream pomIS = JarFinderServlet.class.getClassLoader().getResourceAsStream( RESOURCE_PATH );

  if( null == pomIS )
     throw new MavenhoeException("Can't read fake pom template - getResourceAsStream( RESOURCE_PATH ) == null");

  Map map = ArrayUtils.toMap(  new String[][]{
     {"@GRP@", artifactInfo.getGroup() },
     {"@ART@", artifactInfo.getName() },
     {"@VER@", artifactInfo.getVersion() },
     {"@PACK@", artifactInfo.getPackaging() },
     {"@NAME@", artifactInfo.getFileName() },
     {"@DESC@", req.getQueryString() },
  } );


  //  This does not replace anything, no idea why. //
  ReplaceStringsInputStream replacingIS = new ReplaceStringsInputStream(pomIS, map);
  ReplaceStringInputStream replacingIS2 = new ReplaceStringInputStream(pomIS, "@VER@", "0.0-AAAAA");
  ReplaceStringInputStream replacingIS3 = new ReplaceStringInputStream(pomIS, "@", "#");

  ServletOutputStream os = resp.getOutputStream();
  IOUtils.copy( replacingIS, os );
  replacingIS.close();

这没有用。它只是不更换。于是我使出了“PHP之道”……

  String pomTemplate = IOUtils.toString(pomIS)
  .replace("@GRP@", artifactInfo.getGroup() )
  .replace("@ART@", artifactInfo.getName() )
  .replace("@VER@", artifactInfo.getVersion() )
  .replace("@PACK@", artifactInfo.getPackaging() )
  .replace("@NAME@", artifactInfo.getFileName() )
  .replace("@DESC@", req.getQueryString() );

  ServletOutputStream os = resp.getOutputStream();
  IOUtils.copy( new StringInputStream(pomTemplate), os );
  os.close();

有效。

怎么了？

Answer 1

IOUtils.copy 调用 read(byte[]) 方法而不是 read()，它被 ReplaceStringInputStream 的父类(super class) FixedTokenReplacementInputStream 覆盖。您应该自己实现复制，例如，如下所示:

try {
int b;
while ((b = pomIS.read()) != -1) {
    os.write(b);
}} finally { os.flush();os.close(); }