Java文件和bytearray或Inputstream
题
我想使用jfugue在小程序中播放一些MIDI音乐。 MIDI模式有一个课程 - Pattern
- 加载模式的唯一方法是来自文件。现在,我不知道小程序如何加载文件,什么不加载,但是我正在使用使加载资产成为简单任务的框架(纸浆)。如果我需要从拉链目录中获取资产,我可以使用 Assets
提供的类 get()
和 getAsStream()
方法。 get()
将给定资产作为一个 ByteArray
, ,另一个 InputStream
.
我需要jfugue来加载模式 ByteArray
或者 InputStream
。在伪代码中,我想这样做:
Pattern.load(new File(Assets.get("mymidifile.midi")));
但是,没有任何文件构造函数可以使用bytearray。建议吗?
解决方案
的确,Jfugue不允许加载文件以外的任何东西,这是可耻的,因为没有什么可以阻止使用任何其他类型的流:
public static final String TITLE = "Title";
public static Pattern loadPattern(File file) throws IOException {
InputStream in = new FileInputStream(file);
try {
return loadPattern(in);
} finally {
in.close();
}
}
public static Pattern loadPattern(URL url) throws IOException {
InputStream in = url.openStream();
try {
return loadPattern(in);
} finally {
in.close();
}
}
public static Pattern loadPattern(InputStream in) throws IOException {
return loadPattern(new InputStreamReader(in, "UTF-8")); // or ISO-8859-1 ?
}
public static Pattern loadPattern(Reader reader) throws IOException {
if (reader instanceof BufferedReader) {
return loadPattern(reader);
} else {
return loadPattern(new BufferedReader(reader));
}
}
public static Pattern loadPattern(BufferedReader bread) throws IOException {
StringBuffer buffy = new StringBuffer();
Pattern pattern = new Pattern();
while (bread.ready()) {
String s = bread.readLine();
if ((s != null) && (s.length() > 1)) {
if (s.charAt(0) != '#') {
buffy.append(" ");
buffy.append(s);
} else {
String key = s.substring(1, s.indexOf(':')).trim();
String value = s.substring(s.indexOf(':')+1, s.length()).trim();
if (key.equalsIgnoreCase(TITLE)) {
pattern.setTitle(value);
} else {
pattern.setProperty(key, value);
}
}
}
}
return pattern;
}
更新(对于LoadMidi)
public static Pattern loadMidi(InputStream in) throws IOException, InvalidMidiDataException
{
MidiParser parser = new MidiParser();
MusicStringRenderer renderer = new MusicStringRenderer();
parser.addParserListener(renderer);
parser.parse(MidiSystem.getSequence(in));
Pattern pattern = new Pattern(renderer.getPattern().getMusicString());
return pattern;
}
public static Pattern loadMidi(URL url) throws IOException, InvalidMidiDataException
{
MidiParser parser = new MidiParser();
MusicStringRenderer renderer = new MusicStringRenderer();
parser.addParserListener(renderer);
parser.parse(MidiSystem.getSequence(url));
Pattern pattern = new Pattern(renderer.getPattern().getMusicString());
return pattern;
}
其他提示
如果我没有错,则模式文件包含纯文本。使用getAssTream()加载文件,然后使用
BufferedReader br = new BufferedReader(new InputStreamReader(yourStream));
//...
String pattern = convertToString(br); // you should implement convertToString yourself. It's easy. Read the java.io APIs.
yourstream是getAssTream()返回的输入流。然后使用add(字符串...模式)方法加载图案:
add(pattern);
您可以使用此代码(取自 Pattern.loadPattern()
方法):
InputStream is = ...; // Get a stream from the Asset object
// Prepare a pattern object
Pattern pattern = new Pattern();
// Now start reaing from the stream
StringBuffer buffy = new StringBuffer();
BufferedReader bread = new BufferedReader(new InputStreamReader(is));
while (bread.ready()) {
String s = bread.readLine();
if ((s != null) && (s.length() > 1)) {
if (s.charAt(0) != '#') {
buffy.append(" ");
buffy.append(s);
} else {
String key = s.substring(1, s.indexOf(':')).trim();
String value = s.substring(s.indexOf(':')+1, s.length()).trim();
if (key.equalsIgnoreCase(TITLE)) {
pattern.setTitle(value);
} else {
pattern.setProperty(key, value);
}
}
}
}
bread.close();
pattern.setMusicString(buffy.toString());
// Your pattern is now ready
您可以读取字节数组并将其变成字符串。
问题将是Inputstream。有一个StringBufferInputStream,但对StringReader的支持进行了弃用。
byte [] b = Assets.get();
InputStream is = new StringBufferInputStream(new String(b));
Pattern.load(is);
你不想使用 File
, ,你想使用 java.io.ByteArrayInputStream
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