实现InputStream的任意拷贝

ByteArrayOutputStream baos = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len;
while ((len = input.read(buffer)) > -1 ) {
baos.write(buffer, 0, len);
}
baos.flush();
// 打开一个新的输入流
InputStream is1 = new ByteArrayInputStream(baos.toByteArray());
InputStream is2 = new ByteArrayInputStream(baos.toByteArray());

将输入流拷贝成字节数组或输出流

public class StreamUtils{ // 在Spring的包下, 可以直接使用
// 把输入流读取成字符数组
public static byte[] copyToByteArray(@Nullable InputStream in) throws IOException {
if (in == null) {
return new byte[0];
}
ByteArrayOutputStream out = new ByteArrayOutputStream(BUFFER_SIZE);
copy(in, out);
return out.toByteArray();
}
// 把输入流拷贝到输出流
public static int copy(InputStream in, OutputStream out) throws IOException {
Assert.notNull(in, "No InputStream specified");
Assert.notNull(out, "No OutputStream specified");
int byteCount = 0;
byte[] buffer = new byte[BUFFER_SIZE];
int bytesRead = -1;
while ((bytesRead = in.read(buffer)) != -1) {
out.write(buffer, 0, bytesRead);
byteCount += bytesRead;
}
out.flush();
return byteCount;
}
// 读取输入流成字符串
public static String copyToString(@Nullable InputStream in, Charset charset) throws IOException {
if (in == null) {
return "";
}
StringBuilder out = new StringBuilder();
InputStreamReader reader = new InputStreamReader(in, charset);
char[] buffer = new char[BUFFER_SIZE];
int bytesRead = -1;
while ((bytesRead = reader.read(buffer)) != -1) {
out.append(buffer, 0, bytesRead);
}
return out.toString();
}
// 把字符串(根据编码)写到输出流
public static void copy(String in, Charset charset, OutputStream out) throws IOException {
Assert.notNull(in, "No input String specified");
Assert.notNull(charset, "No charset specified");
Assert.notNull(out, "No OutputStream specified");
Writer writer = new OutputStreamWriter(out, charset);
writer.write(in);
writer.flush();
}
}

写数据转成字节数组或输入流

ByteArrayOutputStream bos = new ByteArrayOutputStream(1024);
Writer writer = new OutputStreamWriter(bos, StandardCharsets.UTF_8);
Map<String, String[]> form = request.getParameterMap();
for (Iterator<String> nameIterator = form.keySet().iterator(); nameIterator.hasNext();) {
String name = nameIterator.next();
List<String> values = Arrays.asList(form.get(name));
for (Iterator<String> valueIterator = values.iterator(); valueIterator.hasNext();) {
String value = valueIterator.next();
writer.write(URLEncoder.encode(name, FORM_CHARSET.name()));
if (value != null) {
writer.write('=');
writer.write(URLEncoder.encode(value, FORM_CHARSET.name()));
if (valueIterator.hasNext()) {
writer.write('&');
}
}
}
if (nameIterator.hasNext()) {
writer.append('&');
}
}
writer.flush();
return new ByteArrayInputStream(bos.toByteArray());
}

将字节数组写到缓冲输出流

File file = new File(path);
FileOutputStream fos = null;
BufferedOutputStream bos = null;
try {
fos = new FileOutputStream(file);
bos = new BufferedOutputStream(fos);
bos.write(bytes);
} catch (Exception e) {
e.printStackTrace();
} finally {
if (bos != null) {
try {
bos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}

最后

以上就是优美鞋子为你收集整理的java中输入流&输出流&字节数组&字符之间的转换实现InputStream的任意拷贝将输入流拷贝成字节数组或输出流写数据转成字节数组或输入流将字节数组写到缓冲输出流的全部内容，希望文章能够帮你解决java中输入流&输出流&字节数组&字符之间的转换实现InputStream的任意拷贝将输入流拷贝成字节数组或输出流写数据转成字节数组或输入流将字节数组写到缓冲输出流所遇到的程序开发问题。

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