此代码段位于\sdk\samples\android-19\connection\NetworkConnect\NetworkConnectSample\src\main\java.com\example\android\NetworkConnect\MainActivity.java中，该代码段根据Apache许可证2.0版授权，由Google编写。

/** Reads an InputStream and converts it to a String.
 * @param stream InputStream containing HTML from targeted site.
 * @param len Length of string that this method returns.
 * @return String concatenated according to len parameter.
 * @throws java.io.IOException
 * @throws java.io.UnsupportedEncodingException
 */
private String readIt(InputStream stream, int len) throws IOException, UnsupportedEncodingException {
    Reader reader = null;
    reader = new InputStreamReader(stream, "UTF-8");
    char[] buffer = new char[len];
    reader.read(buffer);
    return new String(buffer);
}

Use:

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.io.IOException;

public static String readInputStreamAsString(InputStream in)
    throws IOException {

    BufferedInputStream bis = new BufferedInputStream(in);
    ByteArrayOutputStream buf = new ByteArrayOutputStream();
    int result = bis.read();
    while(result != -1) {
      byte b = (byte)result;
      buf.write(b);
      result = bis.read();
    }
    return buf.toString();
}

如果您正在使用Google Collections/Guava，您可以执行以下操作：

InputStream stream = ...
String content = CharStreams.toString(new InputStreamReader(stream, Charsets.UTF_8));
Closeables.closeQuietly(stream);

请注意，InputStreamReader的第二个参数（即Charsets.UTF_8）不是必需的，但如果您知道编码（您应该这样做！）

我会使用一些Java8技巧。

public static String streamToString(final InputStream inputStream) throws Exception {
    // buffering optional
    try
    (
        final BufferedReader br
           = new BufferedReader(new InputStreamReader(inputStream))
    ) {
        // parallel optional
        return br.lines().parallel().collect(Collectors.joining("\n"));
    } catch (final IOException e) {
        throw new RuntimeException(e);
        // whatever.
    }
}

基本上与其他一些答案相同，只是更简洁。

我建议使用StringWriter类来解决这个问题。

StringWriter wt= new StringWriter();
IOUtils.copy(inputStream, wt, encoding);
String st= wt.toString();

最简单的方法，一行：

public static void main(String... args) throws IOException {
    System.out.println(new String(Files.readAllBytes(Paths.get("csv.txt"))));
}